Woven Light: The Orphan Obscura

by Paul Gilster on October 2, 2015

Heath Rezabek began exploring Vessel, an evolving strategy for preserving Earth’s cultures and biology, in these pages back in 2013. A librarian and writer in Austin TX, Heath went on to push these ideas into the realm of science fiction, in the form of a series of excerpts from a longer work that is still emerging. The concluding post in this sequence appears below, though you’ll be hearing more about ‘Woven Light.’ A novel is emerging from this haunting look at how, at various points in our future and with a wide range of technologies, we will interact with the artifacts and stored experience of our past. Heath’s helpful synopsis begins the post.

by Heath Rezabek


For some time, I have had in hand the final chapter – for now – of the Woven Light speculative fiction series as published on Centauri Dreams from 2013 to present. At Paul’s invitation, I am prefacing the final installment with some notes on the series as a whole.

The series began as a way to explore ideas surrounding the prospects for human or posthuman space travel, and the role which might be played by very long term archives in the resilience of life’s efforts to endure. I am not finished with the themes explored in the series, but for now it is time to shelve this particular approach to the storyline, along with its characters.

After feedback last year at the Turkey City Writer’s Workshop in Austin Texas, and encouragement from a few other parties, I am pursuing a new approach to the story arc, from an entirely different time and place in its imaginary history. The goal is to produce a cohesive and more linear novel, exploring world(s) we’ve only glimpsed so far; the Centauri Dreams installments of Woven Light are a (somewhat fragmented and dreamlike) hint at what is to come.

Here follow episode summaries of each of the published episodes, with links to their versions here.

Vessel Haven (I). We are introduced to an entity called Tracer Aakanthia [9T33], who is exploring a holographic archival site. We meet Aben Ramer, encountering a mock-up of a Vessel Haven – a very long term archive – at the Burning Man festival, circa 2023.

Adamantine (II). 
We meet Mentor Kaasura, who is exploring a ruinous region, the site of an ancient disaster. He rests at a pilgrimage shelter. We learn about an artificial life project meant to provide a guiding sentience for a starship. The sentience is named Avatamsaka; the starship – a lightsail – is named Saudade. We also learn about two offshoots of humanity: the Avaai and the Ghemaai.

Augmented Dreamstate (III). 
We meet Aben’s mother, Thea, an author of speculative fiction, as she struggles with a draft of her work. We meet Dr. Jota Kaasura, who bears an unknown relation to Mentor Kaasura from the prior installment. Dr. Kaasura is working on a project called Augmented Dreamstate, which allows the immersive visualization, exploration, and recording of scenarios. He explores one such: the scene on the day of a disaster.

Proteaa (IV). 
We explore a spaceborne habitat derived from an idea of Freeman Dyson, which he’d referred to as an Ark Egg. Here they are called Precursorae, and within them dwell beings called Proteaa. Vannevar Bush’s Memex is considered, along with an exercise developed by Thea Ramer for coaxing concepts out of a flux of random ideas: Wildcards. Dr. Kaasura meets someone unexpected, and dreams of drifting habitats far from the Precursorae.

Lesson Arcs (V). 
Thea Ramer publishes her novel, The Tracer Guild, but life has other plans. Years later, Aben Ramer meets Dr. Kaasura, and lays the groundwork for him to meet with Thea. In another time and place, perhaps aboard our lightsails, we meet Vaarea Ramer, one of the Ghemaai, immersed in worldbuilding lessons that are passed from mind to mind.

Age of Release (VI). 
Mentor Kaasura explores deep passages woven of light, beyond the shelter’s door. Far flung from there, a fog of mind called Ancient Light sifts the space between stars, finding worlds where planetbound life had nearly reached the Age of Release. Aben Ramer determines researches in one of his favorite spots for thinking, and makes a new friend.

For those who would like a plain manuscript version, in sequential order, this PDF can be found here. It includes a short Appendix of previously unreleased developmental fragments from the drafting table].

I look forward to sharing future excerpts from the new effort with Centauri Dreams as well, should Paul welcome it.

Here, at last, is the final installment (for now!) of Woven Light: A special series for Centauri Dreams, 2013-2015.

Woven Light: The Orphan Obscura (VII)

Across town, mother wasn’t doing so well.

Sorting had led to spreads, as Thea rediscovered cards she’d scribbled on years ago, and laid them out the way she remembered, five across to find three akin. She’d pull them aside, and then would remember. How it had felt: To write with an explorer’s eyes, cresting a hill to shine the light of awareness on inevitable mountains.

Eyes closed, still she could see Ityl-Atys spread below her. Wings outspread, a raptor keen and bright of eye . . . She could see the bazaar, the outlying districts, the towers of abandon. Red streaks in distant sun spread golden rivulets, a quilt of sands for all below them.


Image 1: Based on photograph CC BY Michal Huniewicz.

And below, she remembered, delved Vaachez, his dusted hat long since traded in fair exchange for a rough and partial map; his map now guidance through at least one dimension of battered space.

Thea read an untold chapter to herself. So easily, but traceless. No recorder. This time, no traces. She only wanted to know.

~ I only want to know. ~

Vaachez made his way along the higher moraine, beams and slabs settled well for this stratum, clearstone lending its glow to light his way.

His pack was both lighter and more burdensome now, its baubles and bits traded for rarified things needed further down, when stealth failed him. So far, trading had sufficed. But trading had grown more scarce since the post where Oaami, his guide, had bowed, and remained behind. “All I have left to offer, I have whispered to this map,” she had said; and handing it to him, she had turned to her ascent.

From there, he had endured the broken way with only scrapes and the parching isolation of stealth to test him.

In time, even the need for stealth had faded, as the last small settlements carven into these caverns had scattered, and subsided altogether. But the weight he carried now was of most use down here; his ascent would depend on encountering someone else descending, the only ones for whom such things would hold the value they held for him now.

He’d had no word of other tracers when he’d ducked into the shade of the lower bazaar. He couldn’t depend on them. So far as he knew, he was the only pathfinder still drawn to this old mystery.

He had to know. Ascent or an ending, he only wanted to know.

Vaachez worked his way slowly around the edge of a drop, a good ten stories, rusty cable scraping the leather of his gloves, smell of dust and sunbeams still (thank the moon) refined by his breather.

Around the bend; only a little further, if this map was anything at all.

Across the way, just then, he glimpsed it: a bird of some sort, winged its way across the chamber above this blockage. Setting sunlight from a shaft far above them caught its wingtips: a dash of burnished wings. A piercing cry. Alight and keen, now, on the opposite ledge.

A clambering clatter in the softlight, ancient ledgers falling still. Vaachez stood, staring straight at the watcher and pierced right through in return. He couldn’t make out the size of the bird, but its shape was nearly regal. So sharp and feral, whittled by chance and opportunity.

It shifted one leg; he did the same. Nothing gave. Exhaling, Vaachez turned to see the rumored landing not a dozen streetwidths on. From there, by map, the ruins descended in wide slabs and steps, far enough that by the time he reached the fabled site, dusk would have fallen far above. Already the air was quickly cooling.

Inhaling again: ~ All things struggle ~. Exhaling again: ~ On each other we depend. ~ Vaachez switched his grip upon the cable, and stepped ahead.

From its perch, the great raptor could see the dustling balance and edge onwards, surefooted and determined.

Hours later, now sharpened in the cool air from his slow descent of switchbacks, he rested. Vaachez stood again on solid slabwork, trying to adjust his eyes to blue shadows. On beams and slabs around him, he thought at one point he had glimpsed vegetation. How possible was that, so far down below? He climbed the final rise, a silent beachhead, and stood before . . .

At first he saw a mountain. Before his mind could calm his heart he felt it sink at the thought of another climb. But no: this was an illusion. Peak there was, quite clearly rising, all in dusky blue and — yes — clad in clambering green. Darkling down below, it rose and reared at the peak as a beam full of moonlight was filtered down to impossible pools at the base of the beamwork.

And beamwork it was: a steeple of sorts, tentpoled and rising, rooted in its subterranean oasis, foundations wide at the base. There, perhaps, it sat: the Orphan, Obscura. How could he know?

Seeing himself at a ledge, an impassable drop to the oasis below, he stopped, and sat, and stared.

By now his eyes had adjusted quite well to the indigo dark, and he could see and sense that the ruin was extensive, though not as massive as some above ground. But sheltered in this space, this domed duskland, it seemed as if a miniature of something vast. Truth enough was that he couldn’t tell. It couldn’t be as large as it seemed. The space was so quiet, the air so still, the sound of water trickling so clear in the silence it carved.

Inhaling again; exhaling again.

Behind him, a cry: and a winged shadow passed not so far above his shoulder, on his right. Friend from the ledge-crossing, it needed a name. And as it made its way across the gap to perch on rising angles, he decided its name was Zinn.

The distance was greater than he’d thought; the edifice was huge. It slumber was deep. Its voice . . .

He sat before the Orphan. He would speak with it, or nothing.


Image 2: Based on photograph CC BY-SA Al Jazeera

Letting his focus go soft, he steadied his gaze and his breathing, until before him in the settled shape of the ruins he could see a seated figure, Grandfather Silence, casting long shadows. And as his gaze drifted, it fell like the dust, and settled on wellsprings deep at the base . . . And tilted his gaze as he found there a gap of a threshold. Uncertain, he still saw what seemed like — another. Seated at the entry, a tiny mountain settled down beneath the mountainous shadow. Who would break the stillness? Who would answer?

He broke the stillness. ~ I sit before you, a traveller and a friend. I have heard only whispers, but even rumors have a cause. ~

Only dust in deep night air, so slowly.

~ I am called Vaachez. I am an orphan like you. ~

And as Zinn watched, the figure sat with silence.

And the silence stretched on, and on.

~ He has come a long way, ~ croaked Zinn. ~ He has come to know your tale. ~

The Orphan Obscura stirred then, and murmured; ~ He knows it already. ~

Zinn shook and settled, a flutter and a silence like an avian shrug. ~ He may have forgotten. ~

~ Then he is not the one to discover it anew. ~

Zinn cocked one eye, and sized the dustling up and down. ~ He may be the last. Their house is fading. ~

~ He may be the first. Their house is a seedling. ~ The Orphan Obscura shifted something, from one place inside its expanse to another.

~ If he leaves without knowing, he leaves without purpose. ~

Obscura muttered. ~ If he leaves without knowing, he leaves too soon. ~

Perturbed by this back and forth, Zinn took wing, sailing up into the rafters, and swinging down towards the base, where Vaachez’ watery eyes were still fixed. And landing there, she found a pile.

~ What is this heap? ~ She picked at the leaves.

~ It sits and waits. ~ Obscura surveyed a shallow pool at its feet, located a treasure.

~ No time to wait! ~ A fluttering dance. ~ The sun is near! The moon is full! The sleepy stir and soon they’ll wake; for what, a pile? A heap of memories? ~ Zinn darted down to peck at something shiny.

~ A heap of time, slow and intact. That is no small thing. ~ Obscura turned a stone slowly in its gaze, and beneath the stars its etchings caught the ancient light. ~ I have done what I can. ~

Zinn circled the stack of remnants there, wondering if Vaachez could read at such a distance.

She decided he could, and took wing.

~ You’ve done what you can; and so have I. ~

Vaachez sat, parched and quite lonely. The bird had flown suddenly, surely, up and beyond the loose strata far above him. He was alone with his vigil.

Before him slumped a place where forgotten things slept, and waited for a stronger will than his to wake them. But Zinn had been right about one thing: his eyes were keen. And he could read, in that cairn of debris far below, a secret hint of kindness.
Vaachez mulled his reckonings.

All about him, far above him, intolerable weight bent, balanced over its remnants. The Orphan Obscura was not alone, and several more of its kind lay at rest, he knew, slumbering guardians at the roots of other citistates. But if they were all as drowsy as Obscura, there was no way the long work of the Tracer-Guild, and the pathfinders before them, and the dreamhunters before that, could ever come to fruition.

~ Sojourner, peace. You are not alone; nor am I. ~

Vaachez opened his eyes, not realizing they’d been closed, to see the color changed in this space from dusk to slow dawning. He leaned in, peering closely at the form at ruin’s threshold, before the climbing light in this chamber swamped his eyes. Already it was growing violet.

~ A thousand ruins does not a remembrance make. ~ Vaachez furrowed, scolded the fading night.

~ A thousand and one. It takes only one, unruined and found, to spark a rekindling.
~ Obscura raised its gaze, and still could see the moon. Something on its surface glinted, and it too was unalone.

Vaachez rose. Of course the citistate Orphans weren’t the only Orphans out there. Just the most encumbered.

He would find another. He would find a site intact. Would he have to leave the Tracer-Guild, or would they understand?

He looked down at the water, hoping it wasn’t a trick of the mind. He’d need to fill his skins before he made his ascent. Shifting his glance to his rope, he surveyed the situation. He had to get down there, and he had to get back up.

Now that he knew what the seated one sat with, he believed he could see a way. Weighing his chance in his hands, he took it.

The cavern was filled with sudden sun.

– – –

Thea awoke, late afternoon blazing low on mountaintops.

“Shit. You’re kidding me.”

Why no recorder? She was out of practice, and should have known she’d fall asleep. She turned to sit, fumbling for her pad. What was it? A greenish-blue tent in a forest; winter trees overhead; a nightingale?

“Stop and go back.” She clenched her eyes shut and hit record.

“There was a tent, and a full moon. Someone sat and watched and waited. A birdsong, down at the base of the tent… A pile of leaves? A pile of papers? Stones? A pile of something.”


“But there was a glimmer in there, underneath or beside it… And I got the impression there are others. Other campsites I guess . . .”

Thea picked at a quilt thread.

“. . . In greener forests . . .”

Greener than green. “All those years, I was afraid of ending this thing.” She looked over at her bedside shelves, at her work, paperbacked.

“Work. I’ve got work to do. At least I should finish the report. Where’s Aben?” She went to send a message, then remembered her son was a grown man already.
Bluer than blue. “I lost it. I’ll try again tomorrow. This time I’ll record from the start. It’s never the same, but it should be related.”

She shut it off, and went to splash her face, and sat at the kitchen table to read back what she had so far.

~ So reluctant. ~

Thea Ramer looked at her life and she sighed.

~ Just sit with it. ~

The sunset lit the pictureframes, the plants and books, the shiny coat of little Dakini, the calico kitten up on her shelves. Golder than gold.


Image 3: Based on photograph CC BY-SA Ryan Cadby

– – –

Notes on the Deployment of Survey Swarm 2B “Peripheral Vision”
(New York City, Friday September 1, 2023)

The second phase of our survey project utilized a reoptimized scanning algorithm which sought to double the scale and resolution of the initial test survey. My lab at Cornell had developed the algorithm based on analysis of the 2022 data which had suggested that the storage format could accommodate far greater density than we were requiring.

Project lead for the algorithm now known as Peripheral Vision was Ph.D. Candidate Kim Tran, under my supervision. I take full responsibility for what ultimately ensued.

Once site preparations had been completed, the fleet of 64 surveyors were arranged in their starting hexagonal configuration, facing inwards towards the calibration artifact, precisely as specified. The target artifact was a solid tungsten sphere, measuring 20cm in diameter.

The process as planned was for the swarm to self-arrange into a dome configuration around the calibration artifact, and then to commence scanning at n=1 resolution.

Once that scan had been completed, each surveyor was then to pair randomly with another of its peers, the two swapping position to rescan at the same resolution from the new position as an error check and redundant sample.

Finally, once all 32 pairs had completed this process, each would re-select a different random partner, swap positions, and reset their scanning matrices to twice the resolution of the prior pass.

They were then to widen their distance from each other — and thus the swarm’s distance from the artifact — by twice their prior distance, and the process was then to be repeated. The scanning was to cease after four iterations, with a failsafe killswitch coded to kick in after that point if anything in the process had impeded the scan.

– – –

Thea stared through her words, sunken in recollection of what had happened that day.

It could have been much worse. They had lost the swarm, and several technicians had been sent to the ER with concussive shock from the blast. Really, the blast could have been much worse. It all could have been much, much worse.

And then there was the dataset. She turned from her words to stare instead through the dataset.

Aleph. The Myriad Arcana.

When initiated, it had seemed as if the swarm had failed from the start. They failed to reposition at greater distance after the first scan, or the next. Focal beams of bluelight saturated the chamber, tracing and retracing the sample sphere. One sweep; two sweeps; four; then more. Still they hovered, frantically scanning the sphere.

Because sampling had continued to double, even though the surveyors were not repositioning at all, the failsafe code was not engaged. Or perhaps that code knew something its technicians didn’t: it was only when the manual killswitch had been kicked that the surveyors blew to shrapnel, taking out half the observation deck’s retaining wall.

Thea and her team had driven the evacuation, and so she could see light of day beyond the lockdown door when the swarm blew. Flat she laid on pavement, primal fear rekindled to a flaring all around her.

But because the doubling data had shed itself instantly abroad, syncing and resyncing in distributed backups as planned, they still had the bulk of its tattered core. For better or worse it had been unquarantined, because of course they’d immediately want to vouchsafe the data as it streamed from the site… No-one had asked about this yet in the investigation; still it kept her sleepless.

The dataset was so dense that it had already been dubbed a data core by some of her students, and they had only just begun to sample its surface. It had swamped and choked their servers as it had formed, and then their distributed syncs and backups. But now it sat, inert and crystalline, arrayed as woven light; and it could be viewed. Visualized and contemplated, spinning like an ashen star in problem space.

Because it was so large, it had been a lucky break that the syncs had been distributed from the start, or they would never have been able to glimpse it as a whole at all. Yet now, each time they did, each time they sampled a slice and arrayed it with others, they found both gaps and gifts which shouldn’t have been there.

Elements too nearly related for their sampling process to be verified as random.

Samples whose content seemed nothing to do with tungsten.

Avatamsaka had been unborn.



An Asteroid Deflection Investigation

by Paul Gilster on October 1, 2015

Yesterday’s post on what we’re learning about Rosetta’s comet (67P/Churyumov–Gerasimenko) briefly touched on the issue of changing the orbit of such bodies for use in resource extraction. Moving the comet Grigg-Skjellerup is part of the plot of Neal Stephenson’s novel Seveneves, where the idea is to support a growing human population in space with the comet’s huge reserves of water. Just how hard it would be to move a comet is made clear by how a proposed near-term mission approaches the question of deflecting a small asteroid.

The mission, discussed at the ongoing European Planetary Science Congress in Nantes, is called AIDA, for Asteroid Impact and Deflection Assessment. A joint mission being developed by the European Space Agency and NASA, AIDA is actually a two-pronged affair. ESA is leading the Asteroid Impact Mission (AIM), while NASA is behind the Double Asteroid Redirection Test (DART). The plan is to rendezvous with the asteroid (65803) Didymos and its tiny satellite (known informally as ‘Didymoon’) for scientific study and a deflection test.

Think about this comparison: Comet Grigg-Skjellerup (studied by the Giotto probe in 1992, though from a considerable distance) is approximately 2.6 kilometers in diameter. Didymos is about 750 meters in diameter, and the Didymoon about 160 meters across. It’s the Didymoon that ESA and NASA plan on deflecting, driving the DART spacecraft into it as AIM observes and analyzes the plume of ejected material. With AIM remaining on the job, further mapping and monitoring will study the impact area and reveal any changes in Didymoon’s orbit.


Image: Arrival of AIM at Didymos and Didymoon. Credit: ESA.

Thus the spread between a near-future science fiction story (the acquisition of Grigg-Skjellerup for resources in Seveneves) and present-day technology — we can assume that Stephenson’s comet-catcher has some powerful propulsive assets compared to what we can deploy today. But the novel explains all this on its own terms and I’ll say no more about it. As to AIDA, the words of Patrick Michel give us the gist. Michel is lead on the AIM Investigation team:

“To protect Earth from potentially hazardous impacts, we need to understand asteroids much better – what they are made of, their structure, origins and how they respond to collisions. AIDA will be the first mission to study an asteroid binary system, as well as the first to test whether we can deflect an asteroid through an impact with a spacecraft. The European part of the mission, AIM, will study the structure of Didymoon and the orbit and rotation of the binary system, providing clues to its origin and evolution. Asteroids represent different stages in the rocky road to planetary formation, so offer fascinating snapshots into the Solar System’s history.”


Image: Impact on Didymoon, as observed by AIM and its deployed CubeSats. Credit: ESA.

AIM would launch in October of 2020, with rendezvous at (65803) Didymos in May of 2022. Didymos rotates rapidly, about once every 2.26 hours, and is considered the most accessible asteroid of its size from Earth. Didymoon orbits Didymos every 11.9 hours at an altitude of 1.1 kilometers — the name Didymos (Greek for ‘twin’) was chosen by astronomer Joe Montani, who discovered the objects, when light-curve analysis revealed the binary nature of the asteroid. While Didymos is thought to be a ‘chondrite’ (stony) asteroid, we know nothing about the mass and density of Didymoon, a lack that AIM and DART would be able to correct in short order.

The AIM mission has echoes of Rosetta, for like the latter, it carries a lander. MASCOT-2, built by the German aeronautics and space research center (DLR) will probe the internal structure of Didymoon, emitting low-frequency radar waves that will pass through the object, allowing AIM to chart the deep structure of the asteroid even as it measures Didymoon’s density and maps the surface at visible and infrared wavelengths. DART’s impact with Didymoon is scheduled for October of 2022. I also notice that AIM is scheduled to deploy three CubeSats to assist with impact observations and to test communication links between satellites in deep space.

DART itself is a 300 kg impactor that is designed to carry no scientific payload other than a 20-cm aperture CCD camera to support guidance during the impact approach phase. Launch is currently proposed for July of 2021. The impact at 6.25 kilometers per second is expected to produce a velocity change in the range of 0.4 mm/s, which should change the relative orbit of Didymos and Didymoon but create only a slight change in the binary’s heliocentric orbit.

Related: NASA has funded a concept design study and analysis for a mission called Psyche, which would investigate the interesting asteroid of the same name. Psyche is thought to be the survivor of a collision with another object that stripped off the outer layers of a protoplanet. About 200 kilometers in diameter, it is thought to be the most massive M-type asteroid, with a surface that is 90 percent iron. The Psyche mission, led by Linda Elkins-Tanton (Arizona State) would be an orbiter that would launch in 2020 and arrive in 2026.



Off on a Comet

by Paul Gilster on September 30, 2015

Imagine what you could do with a comet at your disposal. In Seveneves, Neal Stephenson’s new novel (William Morrow, 2015), a Musk-like character named Sean Probst decides to go after Comet Grigg-Skjellerup. A lunar catastrophe has doomed planet Earth and humanity is in a frantic rush to figure out how to save at least a fraction of the population by living off-world. Probst understands that a comet would be a priceless acquisition:

“You can’t make rocket fuel out of nickel. But with water we can make hydrogen peroxide — a fine thruster propellant — or we can split it into hydrogen and oxygen to run big engines…. We have to act immediately on long-lead-time work that addresses what we do know. And what we know is that we need to bring water to the Cloud Ark. Physics and politics conspire to make it difficult to bring it up from the ground. Fortunately, I own an asteroid mining company…”

And so on. Lest you think that was a spoiler, be advised that it’s just the tip of a story of Stephensonian complexity. In the world of the novel, even with virtually all the world’s resources committed to putting people and things into space, time is short, and moving a cometary mass will take years. Given today’s technology, we couldn’t move Grigg-Skjellerup the way Probst intends, but I kept thinking about comets and their resources as I pondered the latest news from a comet we’re getting to know very well thanks to Rosetta: 67P/Churyumov–Gerasimenko.

Traveling with a Comet

Rosetta reached Comet 67P/Churyumov–Gerasimenko in August of last year, so we’ve had a year of up-close study, with perihelion of the object’s 6.5 year orbit occurring on August 13 of this year. Watching a comet in action as it reaches perihelion and then recedes from the Sun is what the mission was designed for, and we’re learning that it was money well spent. As the European Space Agency recently reported, we now see a water ice cycle at work on the comet.

The work, which appears in Nature, draws on Rosetta’s Visible, InfraRed and Thermal Imaging Spectrometer (VIRTIS). Lead author Maria Cristina De Sanctis (INAF-IAPS, Rome) explains:

“We found a mechanism that replenishes the surface of the comet with fresh ice at every rotation: this keeps the comet ‘alive’… We saw the tell-tale signature of water ice in the spectra of the study region but only when certain portions were cast in shadow. Conversely, when the Sun was shining on these regions, the ice was gone. This indicates a cyclical behaviour of water ice during each comet rotation.”

The data come from September of 2014, focusing on a single square kilometer region on the comet’s ‘neck,’ an area that at the time was one of the comet’s most active. Rotating roughly every twelve hours, the studied block on 67P/Churyumov–Gerasimenko moved into and out of sunlight. The researchers believe that water ice on the surface and just below it sublimates when illuminated by the Sun, the gases flowing away from the comet into space. As the region again darkens, the surface cools, and subsurface water ice that briefly continues sublimating freezes out again as the vapor reaches the surface. A new layer of ice is formed, only to sublimate as the cycle starts again when the Sun illuminates that part of the surface.


Image: Maps of water ice abundance (left) and surface temperature (right) focusing on the Hapi ‘neck’ region of Comet 67P/Churyumov-Gerasimenko. By comparing the two series of maps, the scientists have found that, especially on the left side of each frame, water ice is more abundant on colder patches (white areas in the water ice abundance maps, corresponding to darker areas in the surface temperature maps), while it is less abundant or absent on warmer patches (dark blue areas in the water ice abundance maps, corresponding to brighter areas in the surface temperature maps). In addition, water ice was only detected on patches of the surface when they were cast in shadow. This indicates a cyclical behaviour of water ice during each comet rotation. Credit/Copyright: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; M.C. De Sanctis et al. (2015).

So we now have observational proof of the suspected water ice cycle on a cometary surface. The patch of the comet under study accounted for about three percent of the total amount of water vapor being emitted by the whole comet at the same time. Cometary activity, as you would expect, increased as 67P/Churyumov-Gerasimenko neared perihelion, producing abundant data from VIRTIS that will offer a further look as the object’s surface changes.

Further work appearing in Nature (and like the previous paper, discussed at the ongoing European Planetary Science Congress in Nantes, France) gives us a good reading on how the comet wound up with its unusual shape. The culprit: A low-speed collision between two separately formed comets. Lead author Matteo Massironi (University of Padova, Italy), an associate scientist of the OSIRIS team, used a 3D model to determine the slopes of over 100 terraced features seen on the comet’s surface, visualizing how they extended into the subsurface. The features were found to be coherently oriented around the comet’s lobes.

“It is clear from the images that both lobes have an outer envelope of material organised in distinct layers, and we think these extend for several hundred metres below the surface. You can imagine the layering a bit like an onion, except in this case we are considering two separate onions of differing size that have grown independently before fusing together.”

The ordered strata uncovered by Massironi and team show that a low-speed collision was the only way for the objects to merge while preserving the ordered strata found deep in the comet. So we can call 67P/Churyumov-Gerasimenko a ‘contact binary,’ one with a history that explains how it got its distinctive shape, which many people liken to a ‘rubber duck.’ Variations in the surface today are likely caused by different rates of sublimation. The frozen gases embedded within individual cometary layers are not necessarily distributed evenly throughout the comet.


Image (click to enlarge): Left: high-resolution OSIRIS images were used to visually identify over 100 terraces (green) or strata – parallel layers of material (red dashed lines) – in exposed cliff walls and pits all over the comet surface (top: Hathor and surrounding regions on comet’s small lobe; bottom: Seth region on comet’s large lobe). Middle: a 3D shape model was used to determine the directions in which the terraces/strata are sloping and to visualise how they extend into the subsurface. The strata ‘planes’ are shown superimposed on the shape model (left panel) and alone (right panel) and show the planes coherently oriented all around the comet, in two separate bounding envelopes (scale bar indicates angular deviation between plane and local gravity vector). Right: local gravity vectors visualised on the comet shape model perpendicular to the terrace/strata planes further realise the independent nature of the two lobes. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; M. Massironi et al. (2015)

Will we one day use comets the way Neal Stephenson’s character describes in Seveneves? Supporting a human presence in deep space will involve ‘living off the land’ and utilizing resources like these. We’ll doubtless one day look back on the pioneering work of the Rosetta team and remember how much Comet 67P/Churyumov-Gerasimenko had to teach us.

The paper on the water/ice cycle is De Sanctis et al., “The diurnal cycle of water ice on comet 67P/Churyumov–Gerasimenko,” Nature 525 (24 September 2015), 500-503 (abstract). The paper on the comet’s shape is Massironi et al., “Two independent and primitive envelopes of the bilobate nucleus of comet 67P,” Nature, published online 28 September 2015 (abstract).



On Habitability around Red Dwarf Stars

by Paul Gilster on September 29, 2015

Learning that there is flowing water on Mars encourages the belief that human missions there will have useful resources, perhaps in the form of underground aquifers that can be drawn upon not just as a survival essential but also to produce interplanetary necessities like rocket fuel. What yesterday’s NASA announcement cannot tell us, of course, is whether there is life on Mars today, though if the detected water is indeed flowing up from beneath the surface, it seems a plausible conjecture that some form of bacterial life may exist below ground, a life perhaps dating back billions of years.

I’ve speculated in these pages that we may in fact identify life around other stars — through studies of exoplanet atmospheres — before we find it elsewhere in our Solar System, given the length of time we have to wait before return missions to places like Enceladus and Europa can be mounted. Perhaps the Mars news can help us accelerate that schedule, at least where the Red Planet is concerned.

Meanwhile, we continue to construct models of habitability not just for Martian organisms, but for more advanced creatures on planets around other suns. As witness today’s topic, recent work out of the University of Washington that is showing us that what seemed to be a major problem for life on planets around red dwarfs may in some cases actually be a blessing.

Of Tides and Magnetic Fields

Our understanding about planets around red dwarf stars is that potentially habitable worlds are close enough to their star to be tidally locked, with one side always facing the star. We’re seeing interesting depictions of such worlds in recent science fiction, such as Stephen Baxter’s Proxima (Roc, 2014), where a habitable planet around Proxima Centauri undergoes ‘winters’ due not to axial tilt but varying levels of activity on the star itself. But tidal locking is problematic, as is the process of getting into it. Circularizing an orbit creates tidally generated heat that can affect surface conditions as well as any magnetic field.

Will planets like these have magnetic fields in the first place?According to Rory Barnes (University of Washington), the general belief among astronomers is that they’re unlikely, a conclusion the new work rejects. It’s an important issue because magnetic fields are believed to protect planetary atmospheres from the charged particles of the stellar wind, thus preventing them from being dissipated into space. Such fields can also protect surface life from dangerous radiation, as from flare-spitting M-dwarfs.


Image: An artist’s impression of the Gliese 667 system from one of the super-Earths that orbit Gliese 667C. Image credit: ESO/M. Kornmesser.

The new paper from Barnes and former UW postdoc Peter Driscoll (now at the Carnegie Institution for Science) takes a look at magnetic fields on planets around red dwarfs. Driscoll began with an examination of tidal effects. In our Solar System, think of Io, its surface punctuated by volcanic activity, to see tidal heating in action. Says Driscoll: “The question I wanted to ask is, around these small stars, where people are going to look for planets, are these planets going to be roasted by gravitational tides?”

And what would be the effect of tidal heating on magnetic fields over the aeons? To find out, Driscoll and Barnes used simulations of planets around stars ranging from 0.1 to 0.6 of a solar mass. Their finding is that tidal heating can help by making a planetary mantle more able to dissipate interior heat, a process that cools the core and thus helps in the creation of a magnetic field.

Thus we have a way to protect the surface of a red dwarf’s planet in an environment that can show a good deal of flare activity in the early part of the star’s lifespan. “I was excited to see that tidal heating can actually save a planet in the sense that it allows cooling of the core,” says Barnes. “That’s the dominant way to form magnetic fields.” A planet in the habitable zone of a red dwarf in its early flare phase may have just the protection it needs to allow life.

But note the mass threshold described in the paper:

…tides are more influential around low mass stars. For example, planets around 0.2 Msun stars with eccentricity of 0.4 experience a tidal runaway greenhouse for 1 Gyr and would be tidally dominated for 10 Gyr. These time scales would increase if the orbits were fixed, for example by perturbations by a secondary planetary companion. We find a threshold at a stellar mass of 0.45Msun, above which the habitable zone is not tidally dominated. These stars would be favorable targets in the search for geologically habitable Earth-like planets as they are not overwhelmed by strong tides.

With stellar mass as the key, as explored in the paper over a range of masses and orbital eccentricities, various outcomes emerge. Planets with low initial eccentricity experience only weak tides, while planets on highly eccentric orbits experience much stronger effects – high initial eccentricity and tight orbits around low mass stars produce extreme tides that help to circularize planetary orbits. As the mass of the star increases, the habitable zone moves to larger orbital distances and tidal dissipation decreases.

Given all these scenarios, helpful magnetic fields are only one possible outcome, and even when they form, they may not be sufficient to protect life. The Driscoll/Barnes model includes planetary cores that undergo super-cooling, thus solidifying and killing the magnetic dynamo. Also, hotter mantle temperatures and lower core cooling rates can weaken the magnetic field below the point at which it can protect the planet’s surface.

Other possibilities: Planets orbiting close to their star in highly eccentric orbits will experience enough tidal heating to produce a molten surface. Tidal heating can also produce high rates of volcanic eruption, producing a toxic environment for life (the atmospheres of such planets may well be detectable with future generations of space- and ground-based telescopes). Tidal heating effects are most extreme for planets in the habitable zone around very small stars, those less than half the mass of the Sun.

So we don’t exactly have a panacea that makes all red dwarf star planets in the habitable zone likely to support life. What we do have is a model showing that for worlds orbiting a star of above 0.45 solar masses, the tidal effects do not overwhelm the possibilities for surface life while they do allow the formation of a protective magnetic field. Some of the magnetic fields generated last for the lifetime of the planets.

Needed improvements in the model, the paper suggests, include factors like variable internal composition and dissipation in oceans or internal liquid layers. “With growing interest in the habitability of Earth-like exoplanets, the development of geophysical evolution models will be necessary to predict whether these planets have all the components that are conducive to life.”

The paper is Driscoll and Barnes, “Tidal Heating of Earth-like Exoplanets around M Stars: Thermal, Magnetic, and Orbital Evolutions,” Astrobiology Vol. 15, Issue 9 (22 September 2015). Abstract / preprint.



Pluto, Bonestell and Richard Powers

by Paul Gilster on September 28, 2015

Like the Voyagers and Cassini before it, New Horizons is a gift that keeps on giving. As I looked at the latest Pluto images, I was drawn back to Chesley Bonestell’s depiction of Pluto, a jagged landscape under a dusting of frozen-out atmosphere. Bonestell’s images in The Conquest of Space (Viking, 1949) took the post-World War II generation to places that were only dimly seen in the telescopes of the day, Pluto being the tiniest and most featureless of all.

But paging through my copy of the book, I’m struck by how, in the case of Pluto, even Bonestell’s imagination failed to do it justice. The sense of surprise that accompanies many of the incoming New Horizons images reminds me of Voyager’s hurried flyby of Neptune and the ‘canteloupe’ terrain it uncovered on Triton back in 1989. On Pluto, as it turns out, we have ‘snakeskin’ terrain, just as unexpected, and likewise in need of a sound explanation.


Image: In this extended color image of Pluto taken by NASA’s New Horizons spacecraft, rounded and bizarrely textured mountains, informally named the Tartarus Dorsa, rise up along Pluto’s day-night terminator and show intricate but puzzling patterns of blue-gray ridges and reddish material in between. This view, roughly 530 kilometers across, combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14, 2015, and resolves details and colors on scales as small as 1.3 kilometers. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Taken near the terminator, the image teases out a pattern of linear ridges. What exactly causes a striated surface like this on a world so far from the Sun? I fully understand William McKinnon’s almost startled reaction to the image. McKinnon (Washington University, St. Louis) is a New Horizons Geology, Geophysics and Imaging (GGI) team deputy lead:

“It’s a unique and perplexing landscape stretching over hundreds of miles. It looks more like tree bark or dragon scales than geology. This’ll really take time to figure out; maybe it’s some combination of internal tectonic forces and ice sublimation driven by Pluto’s faint sunlight.”

The Pluto image below has an abstract quality that combines with our awareness of its location to create an almost surreal response. I’m reminded more than anything else of some of Richard Powers’ science fiction covers — Powers was influenced by the surrealists (especially Yves Tanguy) and developed an aesthetic that captured the essence of the hardcovers and paperbacks he illustrated. This starkly set view of mountains of ice amidst smooth plains could be a detail in a Powers cover for Ballantine, for whom he worked in the 1950s and 60s.


Image: High-resolution images of Pluto taken by NASA’s New Horizons spacecraft just before closest approach on July 14, 2015, are the sharpest images to date of Pluto’s varied terrain – revealing details down to scales of 270 meters. In this 120-kilometer section taken from the larger, high-resolution mosaic, the textured surface of the plain surrounds two isolated ice mountains. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Just for fun, here’s a Powers piece to make the point. ‘The Shape Changer’ was painted in 1973 for a novel by Keith Laumer.


But back to Pluto itself. Below we have a high resolution image showing dune-like features and what this JHU/APL news release describes as “the older shoreline of a shrinking glacial ice lake, and fractured, angular, jammed-together water ice mountains with sheer cliffs.”


Image: High-resolution images of Pluto taken by NASA’s New Horizons spacecraft just before closest approach on July 14, 2015, reveal features as small as 250 meters across, from craters to faulted mountain blocks, to the textured surface of the vast basin informally called Sputnik Planum. Enhanced color has been added from the global color image. This image is about 530 kilometers across. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

The wide-angle Ralph Multispectral Visual Imaging Camera (MVIC) gives us a view of Pluto’s colors in the image below, as John Spencer (GGI deputy lead, SwRI) explains:

“We used MVIC’s infrared channel to extend our spectral view of Pluto. Pluto’s surface colors were enhanced in this view to reveal subtle details in a rainbow of pale blues, yellows, oranges, and deep reds. Many landforms have their own distinct colors, telling a wonderfully complex geological and climatological story that we have only just begun to decode.”


Image: NASA’s New Horizons spacecraft captured this high-resolution enhanced color view of Pluto on July 14, 2015. The image combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC). The image resolves details and colors on scales as small as 1.3 kilometers. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Finally, we trace the distribution of methane across Pluto’s surface, seeing higher concentrations on the bright plains and crater rims, much less in darker regions.

“It’s like the classic chicken-or-egg problem,” said Will Grundy, New Horizons surface composition team lead from Lowell Observatory in Flagstaff, Arizona. “We’re unsure why this is so, but the cool thing is that New Horizons has the ability to make exquisite compositional maps across the surface of Pluto, and that’ll be crucial to resolving how enigmatic Pluto works.”


Image: The Ralph/LEISA infrared spectrometer on NASA’s New Horizons spacecraft mapped compositions across Pluto’s surface as it flew past the planet on July 14, 2015. On the left, a map of methane ice abundance shows striking regional differences, with stronger methane absorption indicated by the brighter purple colors, and lower abundances shown in black. Data have only been received so far for the left half of Pluto’s disk. At right, the methane map is merged with higher-resolution images from the spacecraft’s Long Range Reconnaissance Imager (LORRI). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

In a chapter of The Conquest of Space called “The Solar Family,” Chesley Bonestell described what was then known about the nine planets of the Solar System, taking readers through the search for the ‘Trans-Neptune,’ the world we would learn to call Pluto. Everything about the Trans-Neptune turned out to defy expectations, he explains, noting that most astronomers of the time assumed it would be of about Neptune’s size, of low density and in an orbit far beyond Neptune’s. He writes:

Since everything turned out to be different from expectations, it is not surprising that a few of the old guard which did the theorizing tend to feel that Pluto is not the ninth planet they had been looking for, but an unexpected and unsuspected extra member of the solar family. The real ‘Trans-Neptune’ might still be undiscovered.

Even then, Pluto’s status as a planet seems to have been ambiguous, and today we hear speculations about another world in a far more distant orbit that could influence the trajectories of outer system objects like Sedna. In every way, it seems, Pluto has stirred the imagination while confounding our theories. The continuing dataflow from New Horizons deepens that tradition, and perhaps also contains the clues we’ll need to resolve Pluto’s mysteries.



Seeing Alien Power Beaming

by Paul Gilster on September 25, 2015

We’ve long discussed intercepting not only beacons but stray radio traffic from other civilizations. The latter may be an all but impossible catch for our technology, but there is a third possibility: Perhaps we can intercept the ‘leakage’ from a beamed power infrastructure used to accelerate another civilization’s spacecraft. The idea has been recently quantified in the literature, and Jim Benford examines it here in light of a power-beaming infrastructure he has studied in detail on the interplanetary level. The CEO of Microwave Sciences, Benford is a frequent contributor to these pages and an always welcome voice on issues of SETI and its controversial cousin METI (Messaging to Extraterrestrial Intelligence).

by James Benford


Beaming of power to accelerate sails for a variety of missions has been a frequent topic on this site. It has long been pointed out that beaming of power for interplanetary commerce has many advantages. Beaming power for space transportation purposes can involve earth-to-space, space-to-earth, and space-to-space transfers using high-power microwave beams, millimeter-wave beams or lasers. The power levels are high and transient and could easily dwarf any of our previous leakage to space.

We should be mindful of the possibilities of increased leakage from Earth in the future, if we build large power beaming systems. It has been previously noted that such leakage from other civilizations might be an observable [1].

Now workers at Harvard have quantified the leakage from beaming for space propulsion, its observables and some implications for SETI. The paper is “SETI via Leakage From Light Sails in Exoplanetary Systems,” by James Guillochon and Abraham Loeb (http://arxiv.org/abs/1508.03043). Theirs is the first work to show quantitatively that beam-powered sailship leakage is an observable for SETI.

Studies have shown that leakage of TV and radio broadcast signals such as TV are essentially undetectable from one star to another. But the driving of sails by powerful beams of radiation is far more focused than isotropic communication signals, and of course far more powerful. Therefore they could be far more easily detected. These are not SETI signals so much as an easily detected aspect of advanced civilizations.

Fast track to Mars

The mission Guillochon and Loeb study is one that previous workers have quantified: interplanetary supply missions using unmanned spacecraft. The ship is a sail with payload, a sailship, propelled via microwave beam from Earth to Mars. Previous work was described here and in New Scientist (see New Sail Design to Reach 60 Kilometers Per Second in Centauri Dreams and “Solar super-sail could reach Mars in a month,” in New Scientist (29 January 2005).

The Mars mission is shown in figure 1: a beam-driven sailship transits from Earth to Mars. An interstellar observer sees the beam accelerating the sail because the beam overlaps the sail to some extent at all distances.

Fig 1 Benford

Figure 1. Schematic of Mars cargo mission via microwave beaming, not to scale. The path of the sailship is the dashed arrow. The inset is the beam profile shown in green overlaying the sail of diameter Ds. The beam always overlaps the sail to some extent.

The beam is accelerated from near Earth and is decelerated by a similar system near Mars. Parameters for the mission are based on my papers on Cost-Optimized SETI Beacons and Sailships [2,3]: 1-ton sailship accelerated to 100 km/sec, beam power 1.5 TW, power duration 3 hours, beam frequency 68 GHz, acceleration 1 gee, transmitter aperture 1.5 km, sail diameter 300 m, sail surface density 4 10-5 kg/m2. (For background, see A Path Forward for Beamed Sails and Detecting a ‘Funeral Pyre’ Beacon).

The calculation in the paper presumes the two planets are in conjunction for the voyage, the distance between the planets at this point is 0.5 AU, and the path, although shown bending in Fig. 1, is in fact almost a straight line between the two planets. Figure 2 shows the trajectory. This yields a 9 day transit time when traveling at 100km/s. Figure 3 shows the launch and arrival trajectories of the sailship.

Fig. 2 Benford

Figure 2. Sail flight from Earth (blue orbit at 12 o’clock) to Mars(red orbit).

Fig. 3 Benford

Figure 3. Top (bottom) panel shows sailship’s launch (arrival). Black curve shows sailship (gray segments, not to scale) leaving Earth (Mars), represented by the blue (red) curve. Blue (red) points represent Earth’s (Mars’) position at evenly spaced intervals. Green lines originating from the planets show beam direction.

The beam always overlaps the sail; that overlap will increase as the sail passes the limit for beam focusing with the given transmitter aperture. Beyond that distance the beam spot swells and the leakage rises as the sailship flies away, until the beam is turned off.

How to See Power Beams

At 100 parsecs (326 light years), beam intensity is estimated to be of order 1 Jansky, which is about 100 times the typical detectability of SETI radio searches. The sweeping action of the beam in Figure 2 has implications for observers. The receiving radio telescope will typically see a rising signal because the beam is beginning to sweep past, then a drop in signal as the sail’s shadow falls on the receiver, then a rise as the beam reappears, followed by a decline. In other words, the time varying history of intensity is a symmetric transient with two peaks with much less (or even nothing) in between. They estimate the timescale for the transit to be of order 10 seconds.

The transmitting and receiving systems will be used pretty constantly because they cost a lot to build, but launch expenses are low — basically the cost of the electrical energy. Because it is doing a transit from one planet to another, this gives an opportunity for us to use our growing knowledge of exoplanets in a clever way.

Because the rapidly accumulating information on exoplanets frequently produces all 6 elements needed to describe the orbits of the transiting planets, one can predict times when we will be in the line of sight of two planets which could be beaming power between each other to drive sailships. This ‘conjunction’ is a matter of our perspective; the two planets are not near each other, merely along our line of sight.

The Guillochon-Loeb paper quantifies this strategy for detecting such leakage transients. They estimate that if we monitor continuously, the probability of detection would be on the order of 1% per conjunction event. They state that “for a five-year survey with ~10 conjunctions per system, about 10 multiply-transiting, inhabited systems would need to be tracked to guarantee a detection” with our existing radio telescopes. Of course the key question is just which planets are inhabited, and that’s what SETI is trying to find out. The leakage would be evidence for that, so this statement is a bit circular.

The recently-announced Breakthrough Listen Initiative will have 25% of the observing time allocated on the Parkes and Green Bank telescopes, so could initiate such a search.


This first-of-its-kind calculation shows that the forthcoming Breakthrough Listen Initiative has a new observable to look for. With enough observing time, the prospects for SETI seem to now be improved. If alien civilizations are using power beaming, as we ourselves will likely do in future centuries, we may observe the leakage of these more advanced societies.

Although not mentioned in the paper, there are two implications:

ETI, having done the same thinking, would realize that they could be observed. They could put a message on the power beam and broadcast it for our receipt at no additional energy or cost. So by observing leakage from power beams we may well find a message embedded on the beam. That message may use optimized power-efficient designs such as spread spectrum and energy minimization [4-5]. That would be more sophisticated than the simple 1 Hz tones looked for back in the 20th Century (see Is Energy a Key to Interstellar Communication?).

When we in future build large power beaming systems we will likely put messages on them. That is, if we’ve addressed the METI issue, meaning that we’ve had enough discussion and agreement by mankind of what we wish to say [6].


1. Gregory Benford, James Benford and Dominic Benford, “Searching for Cost Optimized Interstellar Beacons”, Astrobiology, 10, 491-498 (2010).

2. James Benford, Gregory Benford and Dominic Benford “Messaging With Cost Optimized Interstellar Beacons”, Astrobiology, 10, 475-490, (2010).

3. James Benford, “StarshIp Sails Propelled by Cost-Optimized Directed Energy”, JBIS, 66, 85-95, (2013).

4. David Messerschmitt, “Interstellar communication: The case for spread spectrum”, Acta Astronautica, 81, 227-238, (2012).

5. David Messerschmitt, “Design for minimum energy in interstellar communication”, Acta Astronautica, 107, 20-39, (2015).

6. John Billingham and James Benford, “Costs and Difficulties of large-scale METI, and the Need for International Debate on Potential Risks”, JBIS, 67, 17-23, (2014).



Another Search for Kardashev Type III

by Paul Gilster on September 24, 2015

I have no idea whether we would be able to recognize a Kardashev Type III civilization if we saw one, but the search is necessary as we rule out some possibilities and examine others. As we saw yesterday, the Glimpsing Heat from Alien Technologies project at Penn State has examined data on 100,000 galaxies, finding 93 with mid-infrared readings that merit further study. One thing that we, operating with what we know about physics, would expect from a super-civilization is the production of waste heat, in the temperature range between 100 and 600 K, and that’s why previous searches for Dyson spheres have gone looking for such signatures.

But Kardashev Type III is an extreme reach. We’re talking about a civilization capable of using the energies not just of its own star but of its entire galaxy, and just how this would be done is a question about which we can only speculate. As Erik Zackrisson (Uppsala University) and colleagues do in a new paper that balances nicely against Michael Garrett’s recent study. The Zackrisson paper posits Dyson spheres as one way to harvest radiation energies, and takes as its inspiration a 1999 study by James Annis that considers this method in relation to detecting a galaxy-spanning civilization.

A Dyson sphere would partially shroud a star or, in its extreme form, completely surround it, making vast amounts of radiant energy available for the purposes of its builders. Annis wondered how a civilization building Dyson spheres throughout a galaxy would affect the light output of the galaxy. To study the matter, he suggested using the so-called Tully-Fisher relation, the correlation (in spiral galaxies) between galactic luminosity and rate of rotation.


Zackrisson follows Annis’ lead, knowing that if you can determine a galactic rotation velocity, you can use the Tully Fisher relation to come up with its intrinsic brightness. since the optical brightness of a galaxy shows a consistent relation to the maximum rotation velocity and radius of the galaxy. Annis, using a sample of 137 galaxies, looked for candidates that were darker than they should be, finding no outliers in his admittedly limited dataset. Michael Garrett also used a useful relation, in his case between the mid-infrared output of a galaxy and its radio emissions, one that has been shown to hold over a wide range of luminosity and redshifts, to look for cases where the relation failed.

Image: The Tully-Fisher relation shows that rotation curves can be correlated with luminosity. The higher the luminosity, the higher the maximum rotational velocity.

If there is a Kardashev Type III civilization building Dyson spheres on a galactic scale, its astroengineering projects should not affect the gravitational potential of the galaxy, but they should decrease the total optical luminosity, thus making the galaxy an outlier that would appear less luminous than it should. Zackrisson used Tully-Fisher on a sample of 1359 spiral galaxies drawn from a catalog of galaxies produced in 2007 by Christopher Springob and colleagues. The criterion for KIII candidate galaxies was the one used by Annis, that candidates should be ≥ 1.5 magnitudes below what would be expected from Tully-Fisher (the reasons for the choice have to do with limiting spurious detections and are explained at some length in the paper).

As with Michael Garrett’s study, we find little evidence of Kardashev Type III in the results. The conservative upper limit on the fraction of local disks that meet the criteria for a candidate KIII galaxy is ≲ 3%. But we need to drill down into this. Let me quote from the paper:

In this sample, a total of 11 objects are found to be significantly under-luminous (by a factor of 4 in the I-band) compared to the Tully-Fisher relation, and therefore qualify as Kardashev type III host galaxy candidates according to this test. However, by scrutinizing the optical morphologies and WISE 3.4–22 µm infrared fluxes of these objects, we find nothing that strongly supports the astroengineering interpretation of their unusually low optical luminosities.

So we do have a few anomalous galaxies that evidently owe their peculiarities to astrophysical causes not related to astroengineering on a K-III scale. The paper continues:

Hence, we conclude that their apparent positions in the Tully-Fisher diagram likely have mundane causes, with underestimated distances being the most probable explanation for most of the candidates. Under the assumption that none of them are bona fide KIII objects, we set a tentative upper limit of ≲ 0.3% on the fraction of disk galaxies harbouring KIII civilizations.


Image: This Hubble image shows the scatterings of bright stars and thick dust that make up spiral galaxy Messier 83, otherwise known as the Southern Pinwheel Galaxy. One of the largest and closest barred spirals to us, this galaxy has hosted a large number of supernova explosions, and appears to have a double nucleus lurking at its core. What we have yet to find in galaxies like these is any sign of KIII civilizations. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgement: William Blair (Johns Hopkins University).

Does this mean that galaxy-spanning civilizations do not exist? The answer is no: The paper examines a specific scenario, that such civilizations would construct myriad Dyson spheres to harvest radiation energy, and that the waste heat of these constructions would be observable. We are a species whose experience of technology is negligible compared to a KIII culture, so we cannot know what kind of options they would have available after millions of years of technological development. All we can say for sure based on a study like this is that there is no evidence of massive deployment of Dyson spheres in any of the galaxies studied.

I don’t say this to in any way minimize the value of such work. We can’t know if something is there unless we look for it. We keep looking, then, while trying to imagine what civilizations far in advance of our own might do to use the maximum energy available to them. Ruling out one scenario is cause for a re-calibration of our assumptions and a continuing search.

The paper is Zackrisson et al., “Extragalactic SETI: The Tully-Fisher Relation as a Probe of Dysonian Astroengineering in Disk Galaxies,” in press at The Astrophysical Journal (preprint). The Annis paper is “Placing a limit on star-fed Kardashev type III civilisations,” JBIS 52, pp.33-36 (1999).



No Sign of Galactic Super-Civilizations

by Paul Gilster on September 22, 2015

‘Dysonian SETI’ is all about studying astronomical data in search of evidence of advanced civilizations. As such, it significantly extends the SETI paradigm both backwards and forwards in time. It moves forward because it offers entirely new search space in not just our own galaxy but galaxies throughout the visible universe. But it also moves backward in the sense that we can use vast amounts of stored observational data from telescopes both ground- and space-based to do the work. We don’t always need new instruments to do SETI, or even new observations. With Dysonian SETI, we can do a deep dive into our increasingly abundant digital holdings.

At Penn State, Jason Wright and colleagues Matthew Povich and Steinn Sigurðsson have been conducting the Glimpsing Heat from Alien Technologies (G-HAT) project, which scans data in the infrared from the Wide-field Infrared Survey Explorer (WISE) mission and the Spitzer Space Telescope. This is ground-breaking work that I’ve written about here on several occasions — see G-HAT: Searching For Kardashev Type III and SETI and Stellar Drift for recent articles. Jason Wright himself explained G-HAT in the Centauri Dreams article Glimpsing Heat from Alien Technologies.

Last April, G-HAT produced a paper that found only a small number of galaxies out of the 100,000 studied that showed higher levels of mid-infrared than would be expected, with the significant caveat that there are natural processes at work that could mimic what might conceivably be the waste heat of an advanced civilization, a Kardashev Type III culture deploying the energies of its entire galaxy. This is a finding that shows us, in Wright’s words, that “…out of the 100,000 galaxies that WISE could see in sufficient detail, none of them is widely populated by an alien civilization using most of the starlight in its galaxy for its own purposes.”

A fascinating finding in its own right, because we’re dealing with a large sample of galaxies that are billions of years old. The Kardashev model moves from Type II, a technology capable of using the entire energy output of its star, to Type III, a technology capable of using an entire galaxy’s luminous energies. If we assume a progression toward ever more capable energy harvesting like this, then abundant time has been available for Type III cultures to arise. Those interesting galaxies with a mid-infrared signature larger than expected will receive more study, to be sure, but the result at this point seems stark. None of the galaxies studied show signs of civilizations that are reprocessing 85 percent or more of their starlight into the mid-infrared.


Image: The Sombrero galaxy (M104), a bright nearby spiral galaxy. The prominent dust lane and halo of stars and globular clusters give this galaxy its name. If a Kardashev Type III civilization were engaged here, shouldn’t we be able to detect it? Credit: NASA/ESA and The Hubble Heritage Team (STScI/AURA).

But we keep looking, and those few anomalous galaxies from G-HAT still need explanation. Michael Garrett is general and scientific director for ASTRON (Netherlands Institute for Radio Astronomy). Garrett has been working with data on 93 candidate galaxies found in the most recent paper from G-HAT (citation below). These were the galaxies with mid-infrared values enough out of the ordinary to elicit attention. The G-HAT paper (lead author Roger Griffith) calls them “…the best candidates in the Local Universe for Type III Kardashev civilizations.”

The stellar energy supply of a galaxy as examined in the Kardashev taxonomy is roughly 1038 watts, with waste heat energy expected to be radiated in the mid-infrared (MIR) wavelengths, which means temperatures between 100 and 600 K. Garrett’s new paper notes that the 93 sources G-HAT has found would — if the radiation measured here were interpreted as waste heat — include galaxies reprocessing more than 25 percent of their starlight. But can we make that interpretation? Garrett is quick to add that there are many ways that emissions in the mid-infrared can develop through entirely natural astrophysical processes.

To make a determination about what is actually happening, Garrett relies on a relation known as the infrared radio correlation, which the paper calls a ‘fundamental relation’ for galaxies that holds over a wide range of different redshifts and covers at least five orders of magnitude in luminosity. It extends, as the paper notes, well into the FIR/Mid-Infrared and sub-millimetre domains. The tight correlation between infrared and radio emissions was originally uncovered with data from the IRAS (Infrared Astronomical Satellite) mission, launched in 1983. And it takes us into interesting territory as a diagnostic tool, as the paper notes:

The physical explanation for the tightness of the correlation is that both the non-thermal radio emission and the thermal IR emission are related to mechanisms driven by massive star formation. For galaxies in which the bulk of the Mid-IR emission is associated with waste heat processes, there is no obvious reason why artificial radio emission would be similarly enhanced. While the continuum radio emission level might increase through the use of advanced communication systems, the amount of waste energy deposited in the radio domain is likely to be many orders of magnitude less than that expected at Mid-IR wavelengths.

The Garrett paper, then, looks at the 93 G-HAT sources in terms of the mid-infrared radio correlation, with the assumption that galaxies associated with Type III civilizations should appear as outliers. The result: The correlation holds as expected. The likely interpretation is that the excesses of radiation in mid-infrared wavelengths are due to natural heat sources rather than the heat of a titanic civilization going about its business. Garrett puts the point bluntly: “The original research at Penn State has already told us that such systems are very rare but the new analysis suggests that this is probably an understatement, and that advanced Kardashev Type III civilisations basically don’t exist in the local Universe.”

In an email this morning, I ran today’s post by Jason Wright, who said that Garrett’s study was the kind of thing the G-HAT team had hoped for, an investigation into what might have caused the galactic anomalies by other methods. He also noted that even with this information, we can’t absolutely rule out a K-III:

“Kardashev’s original line of research was to estimate the power available to a KIII to transmit radio waves that we would detect at Earth. Determining that these galaxies are radio bright in a way correlated with their MIR is a good bit of information to have, but it doesn’t rule anything out (they do seem to be consistent with starbursts, as expected, but they’re not inconsistent with KIII’s). On the other hand, there’s no reason I can think of that bright radio emissions from leaked communications would follow the MIR-radio correlation for starbursts (what a coincidence that would be!).”

Or is a Kardashev Type III civilization advanced enough that it produces low waste heat emissions in ways that are beyond our understanding? Whatever the case, the paper adds that the correlation method can be extended into the search for possible Kardashev Type II civilizations within our own or nearby galaxies:

…it should be noted that the IR-radio correlation is also known to hold on sub-galactic scales (e.g. Murphy (2006). A comparison of resolved Mid-IR and radio images of nearby galaxies on kpc scales can also be useful in identifying artificial mid-IR emission from advanced civilisations that lie between the Type II and Type III types. While Wright et al. (2014a) venture that Type III civilisations should emerge rapidly from Type IIs, it might be that some specific galactic localities are preferred – see for example Cirkovic & Bradbury (2006) or are to be best avoided e.g. the galactic centre. A comparison of the resolved radio and mid-IR structures can therefore also be relevant to future searches of waste heat associated with advanced civilisations.

The paper is Garrett, “The application of the Mid-IR radio correlation to the G^ sample and the search for advanced extraterrestrial civilisations,” accepted at Astronomy & Astrophysics (abstract). The Griffith paper on recent G-HAT results is Griffith et al., “The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. III. The Reddest Extended Sources in WISE,” Astrophysical Journal Supplement Series Vol. 217, No. 2, published 15 April 2015 (abstract / preprint).



Pluto as ‘Planet’

by Paul Gilster on September 21, 2015

I have never been exactly indignant about the demotion of Pluto to ‘dwarf planet’ status but I do think it’s curious and in at least one respect too arbitrary for my taste. I’ll buy the idea that a planet needs to be round because of its own gravity, and I’ll sign off on the notion that to be a planet, an object has to be in orbit around the Sun (even though we do have apparent wandering planets in the interstellar deep, far from any star). But the International Astronomical Union also decided in its 2006 deliberations that a planet has to ‘clear’ its neighborhood of debris, thus sweeping out its orbit over time. That one, of course, is controversial.

Assuming the Earth is a planet, why are we worried about things like Near Earth Asteroids (NEAs)? Our planet clearly hasn’t swept out its neighborhood, not when we can number problematic asteroids in the thousands. Jupiter is estimated to have about 100,000 trojan asteroids in its orbital path as well, and Alan Stern, principal investigator for New Horizons, has pointed out on more than one occasion that if Neptune (obviously a planet) had cleared its orbit, Pluto itself wouldn’t be there, and the whole discussion might never have come up.

For that matter, we would not be having this discussion now if not for continuing discoveries in the Kuiper Belt that more or less force the issue. Eris was found in 2005, a world more massive than Pluto and first thought to be larger as well, leading to the temporary designation of it as the ‘tenth planet,’ and raising the question of what to do about a Kuiper Belt that might be stuffed with such objects. Here the matter seems to be one of simple redundancy. Nine, or eight, planets, is acceptable. Several thousand is not — it seems to devalue the notion altogether.

I can see why working this out is still controversial. Meanwhile, from a purely aesthetic point of view, I have a hard time looking at the image below and seeing it as anything other than a planet. Or, as I have said before, the larger component of a binary planetary system.

Fig1_Pluto-Mountains-Plains 9-17-15

Image: Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured a near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 3,500 meters high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto’s tenuous but distended atmosphere. The image was taken from a distance of 18,000 kilometers to Pluto; the scene is 380 kilometers across. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

We see mountains here, plains, glaciers, but what really catches the eye is the multi-layered haze in Pluto’s thin nitrogen atmosphere. Here we’re looking at more than a dozen such layers extending all the way from the surface up to 100 kilometers. Mountains falling into shadow at sunset and a bank of low-lying haze near the terminator give us the sense of looking at a place in a constant state of change, a world laden with active patterns of weather. We seem to have the Plutonian version of a ‘hydrological’ cycle here, substituting nitrogen for water ice.

“We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system,” said Alan Howard, a member of the mission’s Geology, Geophysics and Imaging team from the University of Virginia, Charlottesville. “Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow, and returns to the seas through glacial flow.”

Call this world what you will, the imagery is getting better and better. Here are some recent releases.


Image: In this small section of the larger crescent image of Pluto, taken by NASA’s New Horizons just 15 minutes after the spacecraft’s closest approach on July 14, 2015, the setting sun illuminates a fog or near-surface haze, which is cut by the parallel shadows of many local hills and small mountains. The image was taken from a distance of 18,000 kilometers, and the width of the image is 185 kilometers. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Fig3_Overview_reduced-Annotated 9-17-15

Image: Sputnik Planum is the informal name of the smooth, light-bulb shaped region on the left of this composite of several New Horizons images of Pluto. The brilliantly white upland region to the right may be coated by nitrogen ice that has been transported through the atmosphere from the surface of Sputnik Planum, and deposited on these uplands. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.


Image: Ice (probably frozen nitrogen) that appears to have accumulated on the uplands on the right side of this 630-kilometer wide image is draining from Pluto’s mountains onto the informally named Sputnik Planum through the 3- to 8- kilometer wide valleys indicated by the red arrows. The flow front of the ice moving into Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.


Image: This image covers the same region as the image above, but is re-projected from the oblique, backlit view shown in the new crescent image of Pluto. The backlighting highlights the intricate flow lines on the glaciers. The flow front of the ice moving into the informally named Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. This image is 630 kilometers across. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.



Greg Matloff: Conscious Stars Revisited

by Paul Gilster on September 18, 2015

It’s no exaggeration to say that without Greg Matloff, there would have been no Centauri Dreams. After reading his The Starflight Handbook (Wiley, 1989) and returning to it for years, I began working on my own volume in 2001. Research for that book would reveal Matloff’s numerous contributions in the journals, especially on solar sail technologies, where he illustrated early on the methods and materials needed for interstellar applications. A professor of physics at New York City College of Technology (CUNY) as well as Hayden Associate at the American Museum of Natural History, Dr. Matloff is the author of, among others, Deep Space Probes (Springer, 2005) and Solar Sails: A Novel Approach to Interplanetary Travel (with Les Johnson and Giovanni Vulpetti; Copernicus, 2008). His latest, Starlight, Starbright, is now available from Curtis Press, treating the controversial subject of today’s essay.

by Greg Matloff


Introduction: Motivations

As any web search will reveal, most of my research contributions have been in the fields of in-space propulsion, SETI, Earth-protection from asteroid impacts, planetary atmospheres, extra-solar planet detection and spacecraft navigation. Since I have consulted for NASA on solar-sail applications, I have trained myself to err on the side of conservatism. However, a true scientist cannot ignore observational data. He or she must base hypothesis and theories upon such results, not upon previous experience, ideology and dogma.

Image: Gregory Matloff (left) being inducted into the International Academy of Astronautics by JPL’s Ed Stone.

Until 2011, I never expected that I might contribute to the fascinating debate regarding the origin and nature of consciousness. On one side are the epiphenomenonalists, who believe that consciousness is a mere byproduct of bio-chemical activity in the complex brains of higher organisms. On the other side are the panpsychists, who believe that a universal field responsible for consciousness, sometimes referred to as “proto-consciousness,” reacts with matter to produce conscious activity at all levels. The philosophical arguments were fascinating, but to me as a scientist they were a bit disappointing. There seemed to be no way of elevating the argument from the realm of deductive philosophy to the realm of observational/experimental science.

But in 2011, as documented in my June 12, 2012 contribution to this blog – Star Consciousness: An Alternative to Dark Matter – I learned (much to my surprise) that it may be possible now to construct simple models of universal consciousness and test them against observational evidence.

I was primed for this work by several factors. First, an early mentor of mine and a coauthor of several astronautics papers, was the late Evan Harris Walker. With expertise in plasma and quantum physics, Harris (as his friends called him) was a pioneer in the infant field of quantum consciousness. Although I am far from an expert in quantum mechanics, I was fascinated by Harris’ attempt to explain consciousness by the quantum tunneling of wave functions through potential wells created by the inter-synaptic spacing in mammal brains [1].

After the success of The Starflight Handbook and other contributions to interstellar travel studies, I was asked by Apollo 11 astronaut Buzz Aldrin in the early 1990’s to join the team of scientific consultants for a science-fiction novel he was co-authoring with John Barnes [2]. For plot purposes, Buzz required the stable, long-term existence of a Jupiter-like planet at a 1 Astronomical Unit (AU) distance from a Sun-like star. When he asked me to check the possibility of such a planet, I was initially very pessimistic. When I told Buzz that most exoplanet experts believed that the Hydrogen-Helium atmosphere of such a planet would likely evaporate quickly (in cosmic terms), he asked me to check this assumption. I located an appropriate equation in a space science handbook and calculated the estimated lifetime of the giant planet’s atmosphere. I was surprised and Buzz was gratified to learn that the lifetime of the Jovian’s atmosphere at 1 AU would be billions of years. At that point in my career, I was an adjunct professor and consultant. Since I was unable to locate a derivation for the subject equation, I elected not to challenge scientific orthodoxy and attempt to publish these results in a scientific journal. After the discovery of “hot Jupiters” circling Sunlike stars a few years later, I became credited (by Paul Gilster and others) with predicting the existence of hot Jupiters in a science-fiction novel, but not in a peer-reviewed journal. I vowed to never repeat this mistake again and hold back data, if my results challenged established paradigms.

The third influence pointing me in the direction of conscious stars was an undergraduate, liberal arts student at New York City College of Technology. Between the time I became a tenure-track professor in 2003 and my retirement from full-time teaching in 2011, I organized and coordinated the astronomy program at New York City College of Technology (NYCCT). In the first term of the NYCCT astronomy sequence, students learn about astronomical history, aspects of classical and modern physics and solar-system astronomy. In the second term, they investigate the astrophysics of the Sun, stars, and galaxies, cosmology, and the prospects for extraterrestrial life. In one Astronomy 2 section, I was lecturing about dark matter. The existence of this mysterious substance has been invited to explain anomalous stellar motions. When a liberal arts undergraduate interrupted the lecture, I learned that he doubted dark matter’s existence. His supposition was that physics is at an analogous stage to the situation in 1900. A major shift in physical paradigms may be necessary to explain the many anomalies (including dark matter) building up in observational astrophysics.

In 2011, it all came together. Kelvin Long, who edits the Journal of the British Interplanetary Society (JBIS), invited me to participate in a one-day symposium at the London headquarters of the BIS to celebrate the work of Olaf Stapledon, a British science-fiction author and philosopher who has greatly influenced astronomical and astronautical thought. In his 1937 masterwork Star Maker, Stapledon predicted nuclear energy, nuclear war, interstellar travel, space habitats and rearrangement of solar systems by intelligent extraterrestrials. Because I usually author papers on these topics and have often cited Star Maker, I elected to avoid astrotechnology in my contribution to this BIS symposium and instead concentrate on a core aspect of Stapledon’s philosophy: that the stars and indeed the entire universe are in some sense conscious.

A Toy Model of Stellar Consciousness and Astrophysical Evidence

Many people have written about consciousness. Since there is no agreed upon definition of this quality, I decided to investigate a symptom of stellar consciousness. This is Stapleton’s supposition that a fraction of stellar motions around the centers of their galaxies is volitional. According to Stapledon, stars obey the canons of a cosmic dance as they travel through space. Many researchers consider the seat of consciousness in humans and other lifeforms to be neurons or tubules [1,3,4]. I have little knowledge regarding the intimate details of the stellar interior. But I am pretty sure that neurons and tubules do not exist within stars. However, most cooler stars, including the Sun, do have simple molecules in their upper layers.

Contrary to what many of us learned in high school chemistry, the Van der Waals forces that hold the atoms in molecules together are not purely electromagnetic. Some of this attraction is due to the so-called Casimir Effect [5]. Vacuum is not truly empty. Instead, in tiny intervals of space and time, there are enormous fluctuations of energy and matter. Generally, positive and negative energies in these fluctuations exactly balance. But in the opinion of most cosmologists, the Big Bang was a stabilized vacuum fluctuation. All the matter, energy, space and time in the universe inflated from a tiny volume of dynamic vacuum during this event.

An echo of this most creative event in the universe’s history occurs in every molecule. Not all vacuum fluctuations can fit between adjacent molecules. A fraction of the Van der Waals force holding molecules together is produced by the pressure of these vacuum fluctuations.

With astrophysicist Bernard Haisch [6], I assumed that a proto-consciousness field operates through vacuum fluctuations or is identical to these fluctuations. I developed a very simple “toy model” in which this field produces a form of primitive consciousness by its interaction with molecular matter in the Casimir Effect (Fig. 1).

Fig. 1. A “Toy Model” of Proto-Panpsychism.


But models, no matter how simple or complex, are useful in physics only if they can be validated through experiment or observation. So I conducted a Google search for “Star Kinematics Anomaly and Discontinuity”.

Contrary to my expectation, what appeared on my screen was amazing. There was a Soviet-era Russian astronomer named Pavel Parenago (1906-1960). In addition to his astronomical contributions, Dr. Parenago was a very clever man. Unlike many of his colleagues, he avoided an extended vacation in a very cold place by dedicating a monograph to the most highly evolved human of all times – Joseph Stalin!

The anomaly named after Parenago, which is referred to as “Parenago’s Discontinuity”—is his observation that cool, low-mass stars in our galactic vicinity (such as the Sun) move around the center of the Milky Way galaxy a bit faster than their hotter, higher-mass sisters.

I used two sources to quantify Parenago’s Discontinuity for nearby main sequence stars. One was a chapter in Allen’s Astrophysical Quantities, a standard reference in astrophysics [7]. The second was a compilation of observations of 5610 main sequence stars using the European Space Agency (ESA) Hipparcos space observatory out to a distance of ~260 light years [8]. Figure 2, a graph presenting this data, is also included in my June 12, 2012 contribution to this blog and the JBIS paper based on my contribution to the BIS Stapledon symposium [9].

In Fig. 2, star motion in the direction of galactic rotation is plotted against star (B-V) color index, which is a measure of the difference between star radiant output in the blue range of the spectrum and the center of the human eye’s visual sensitivity. Hot, blue, massive stars have low and negative (B-V) color indices. From Table 19.1 of Ref. 7, G spectral class main sequence stars such as the Sun have (B-V) color indices in the range of about 0.6-0.7.

Fig 2: Solar Motion in Direction of Galactic Rotation (V) for Main Sequence Stars vs. Star Color Index (B-V). Diamond Data Points are from Gilmore & Zelik. Square. Data Points are from Binney et al.


Note in Fig. 2 that cooler stars to the right of the discontinuity move as much as ~20 kilometers per second faster than their hotter sisters around the center of the galaxy. As discussed in the June 12, 2012 contribution to this blog and in Ref. 9, Parenago’s Discontinuity occurs near the point where stable molecules begin to appear in stellar spectra.

Recent Work and Consideration of Alternative Hypotheses

Science is essentially a testing ground of alternative hypotheses to explain observational and experimental data. Since data points to at least the local reality of Parenago’s Discontinuity, some astrophysicists have developed rival explanations to Volitional Stars.

One possibility is stellar boil-off from local stellar nurseries. Perhaps this results in faster motions for cooler, low mass stars. But this process should result in a greater velocity dispersion in low mass stars, not a higher velocity of revolution around the galaxy’s center. Also, stellar nurseries typically live for tens of millions of years [10]. Why is there no discontinuity in the motions of short-lived O and B stars?

If Parenago’s Discontinuity is a local phenomena extending out a few hundred light years from the Sun, at least one other alternative explanation is possible. This is the Spiral Arms Density Waves concept [11]. The matter density of the interstellar medium is not uniform. Although the typical density of ions and neutral atoms in the Sun’s vicinity (the so-called Intercloud Medium) is less than 0.1 per cubic centimeter, matter density in the cooler, mostly neutral diffuse nebula that operate as stellar nurseries in the spiral arms of our galaxy is orders of magnitude greater. If a dense diffuse nebula passed through our galactic vicinity in the distant past, low-mass, cool, redder stars might be dragged along faster by the dense cloud than hot, blue, more massive stars.

There are at least two ways to check the validity of the Spiral Arms Density Waves hypothesis. One is to investigate the typical size of diffuse nebula in the Milky Way galaxy. The second is to check observational consequences of this hypothesis.

In a recent book, I reviewed the sizes of diffuse nebula in Messier’s compilation [12]. As part of a recent research paper, I performed a similar review of the more comprehensive Herschel catalog and an on-line listing of New General Catalog (NGC) deep-sky objects [13]. These results are summarized in Fig. 3.

Fig 3: Fraction of Galactic Bright Diffuse Nebulae with Diameters > D Light Years from Messier (Blue), Herschel (Green) and Atlas of the Universe—NGC (Yellow) Compilations.


Note in Fig. 3 that, in all three compilations of deep-sky objects, diffuse nebulae with diameters greater than a few hundred light years are rare. Since the Hipparcos main sequence dataset used in Ref. 8 includes stars in a ~500 light year diameter sphere, Fig. 3 does not support the Spiral Arms Density Wave hypothesis.

But there is worse news for this hypothesis, also derived from Hipparcos data. Giant stars are considerably brighter than their less evolved counterparts on the main sequence and
are consequently visible over greater distances. Richard Branham, an astrophysicist based in Argentina, has analyzed the kinematics of thousands of giant stars in the Hipparcos data set [14]. His conclusion that Parenago’s Discontinuity is present in these results is demonstrated in Fig. 4.

Fig 4: Giant Star Motion (V) in Direction of Sun’s Galactic Revolution. The reduction of Branham’s data to produce Fig. 4 is discussed in Chap. 23 of Ref. 12.


Note that Fig. 4 is not as neat as the corresponding results for main sequence stars in Fig. 2. This may be due to uncertainty in the > 1,000 light year distance estimates for many of the stars in Branham’s Sample.

An interpretation of the above results is that a local explanation for Parenago’s Discontinuity is unlikely. Existing galactic diffuse nebula are simply too small (and widely separated, as discussed in Ref. 12) to produce a stellar kinematics anomaly over a radius greater than 1,000 light years.

However, although the existing data does not support Spiral Arms Density Waves, the sample of stars, which numbers in the thousands, is not large enough to rule out this and other local explanations for Parenago’s Discontinuity. After all, the Milky Way galaxy contains more than a hundred billion stars.

Within the next few years, astrophysicists should know conclusively whether Parenago’s Discontinuity is a local or galactic phenomenon. In December 2013, the European Space Agency (ESA) launched Gaia as a more capable successor to the Hipparcos space observatory. While Hippasrcos accurately determined the distance and motions of perhaps 100,000 stars,
Gaia should gather similar data over the next few years for about a billion stars in the Milky Way galaxy. Gaia, its mission and capabilities are discussed in more detail in Ref. 12.

Fig 5: The European Space Agency’s Gaia Space Observatory (Courtesy ESA).


But even before the data from Gaia is analyzed and released, astronomers using different equipment have gathered preliminary data that may lead to the falsification of the Spiral Arms Density Waves hypothesis. Note in Fig. 6 the structure of M51, a typical nearby spiral galaxy not dissimilar from the Milky Way. The revolution of this galaxy is in the counterclockwise direction, from our point of view. Hundreds of millions of years are required for one
complete revolution [15].

A team of astronomers have carefully analyzed the light received from the leading and lagging edges of spiral arms of twelve nearby spiral galaxies. For the Spiral Arms Density Waves Hypothesis to be correct, differences should be observable between these two locations. Sadly for Density Waves (and happily for Volitional Stars), such an effect was not noticed.

Fig 6: The Whirlpool Galaxy M51 (courtesy NASA).


Since the universe contains ~100 billion spiral galaxies, this result is not conclusive. Using new telescopes, about 300 spirals should be observed to statistically rule out Density Waves. Density Waves is apparently limping, but it cannot yet be completely ruled out.

If observations from Gaia indicate that Parenago’s Discontinuity is a galactic phenomenon rather than a local phenomenon, some astrophysicists will attempt to develop explanations that are alternatives to Volitional Stars. As discussed in Ref. 13, this will be challenging. The only reasonable galaxy-wide explanation might be a collision between the Milky Way galaxy and another large galaxy in the distant past. While such a collision might have produced a galaxy-wide “starburst” episode of rapid star formation, simulations indicate that the ultimate result of such galaxy smash-ups is a giant elliptical galaxy, not a spiral such as the Milky Way.

Volitional Star Kinematics

In my June 12, 2012 contribution to this blog, I considered methods that a volitional star could use to adjust its galactic velocity. One possibility was stellar jets.

Many infant stars eject high-velocity matter streams (Fig. 7). Surprisingly, some of them are unipolar or unidirectional, ejecting more material in one direction than others [16]. In April 2015, Paul Gilster e-mailed a link indicating that solar winds from mature stars like the Sun
enter interstellar space in a complex system of jets [17]. The complexity of these jets is at least partially due to solar galactic motion and the interaction between the solar and galactic magnetic fields. Uni-directional matter jets from infant and young stars are discussed in greater detail in Chap. 15 of Ref. 12.

Fig 7: A Jet of High-Velocity Material Ejected From an Infant Star (courtesy NASA).


If Gaia observations reveal that Parenago’s Discontinuity is a galaxy-wide phenomenon, attention might turn to these unidirectional stellar jets. Are they generally aligned to accelerate molecule-bearing stars in the direction of their galactic motion? Since star galactic revolution velocities generally increase with distance from the galactic center, do jet velocities increase as well?

Although unidirectional material jets from infant and mature stars is one method that a volitional star could use, there is another possibility. This is the admittedly very controversial possibility of a weak psychokinetic (PK) force. Much has been written about the investigation of PK and related paranormal phenomena funded by US intelligence agencies.

As I have described in my earlier treatments of this subject, this is the only scientific controversy that I am privileged to know participants on opposing sides. On one hand are the physicists who claim that Uri Geller, the alleged psychic who scored best on their screening tests, could not possibly have cheated on these tests. On the other hand, I met a retired Time-Warner editor at a cocktail party years ago who demonstrated that Geller’s signature fork bending could be duplicated as a magic trick, and who also claimed to have enlisted a magician The Amazing Randi, to further investigate Geller.

Many web sources conclude that Geller is indeed a trained magician. When my friend Dr. Eric Davis of the Institute for Advanced Studies at Austin (Texas) mentioned (while reviewing a draft copy of Ref. 12) that there is no confirmation of Geller actually having attended a magician’s college, I decided to check what I consider the best reference available on the Geller-Randi controversy. I carefully checked a book by MIT physics professor David Kaiser on this topic and learned that Dr. Davis is apparently correct [18].

Eric Davis also sent me an electronic copy of a report he authored for the US Air Force in 2005. Many countries other than the US have investigated PK and related phenomena in studies funded by government agencies. Some of the results are positive and have reportedly been replicated [19, 20].

As discussed in Refs. 9 and 12 and my June 12, 2012 submission to this blog, a PK force required to accelerate a Sun-like star by 20 km/s during a ~1-billion-year time interval is many orders of magnitude less than that required to bend a kitchen utensil. Perhaps it is time for experimental physicists to put the Geller-Randi controversy aside and perform a new set of carefully controlled experiments to test the existence or non-existence of a weak PK effect.

One possibility discussed by others is to include professional magicians on the experiment design team. Another possibility, raised by a responder to my June 12, 2012 contribution to this blog, is to perform PK tests on the interaction between human subjects and an Einstein-Bose condensate. As further discussed in Ref. 12, an Einstein-Bose condensate is a macroscopic state of matter in which all of the particles share the same quantum state. A human subject might be instructed to see if he or she could “will” the condensate to climb the enclosure wall repeatedly to the same level. This would test not only the validity of PK but the assumption that consciousness is related to quantum phenomena.

Conclusions: A Learning Experience

Since 2011, I have spent a large fraction of my creative time investigating whether the Volitional Star hypothesis can be considered scientific. As reviewed in Ref. 12, it is certainly a venerable concept. Shamans, astrologers, philosophers, mystery-cult members, poets, and fiction authors have considered this possibility for millennia.

It is also interesting that at least a few scientists have walked this path before me. Although the concepts of stellar or universal consciousness are certainly not in the scientific mainstream at present, scientific speculation along these lines is becoming more respectable.

One creative group that apparently welcomes these concepts is fine artists. The chapter frontispiece art in Ref. 12 created by C Bangs has been presented in several artistic forums, including the Arts Program at the 9th IAA Symposium on the Future of Space Exploration, which was held in Turin, Italy in July 2015. A version of one of these images is presented as Fig. 8. Modifications of 18 of these images on 11” X 14” panels painted on both sides in the form of an accordion book are on display at the Manhattan gallery that C Bangs is affiliated with: Central Booking Art Space, 21 Ludlow Street.

Fig 8: Modified Version of C Bangs Chapter frontispiece from Starlight, Starbright.


Recently, with my assistance, C prepared an Artist’s Book entitled Star Bright?. In July 2015, Star Bright? was collected by the Prints and Illustrated Books division of the Museum of Modern Art in Manhattan.

It is of course very premature to claim that the work presented here has proven the case for volitional stars. The toy model of proto-panpsychism is certainly too simple to have much traction in the theoretical world. But it is not impossible that this work might move panpsychism from the realm of deductive philosophy to the realm of observational astrophysics.


1. E. H. Walker, “The Nature of Consciousness,” Mathematical Biosciences, 7, 131-178 (1970). Also see E. H. Walker, The Physics of Consciousness, Perseus, Cambridge, MA (2000).

2. B. Aldrin and J. Barnes, Encounter with Tiber, Warner, NY (1996).

3. L. Margulis, “The Conscious Cell”, Annals of the New York Academy of Sciences, 929, 55-70 (2001).

4. S. Hameroff, “Consciousness, the Brain, and Spacetime Geometry”, Annals of the New York Academy of Sciences, 929, 74-104 (2001) and R. Penrose, “Consciousness, the Brain, and Spacetime Geometry: An Addendum”, Annals of the New York Academy of Sciences, 929, 105-110 (2001).

5. H. Genz, Nothingness: The Science of Empty Space, Perseus, Cambridge, MA (1999).

6. B. Haisch, The God Theory, Weiser, San Francisco, CA (2006).

7. G. F. Gilmore and M. Zelik, “Star Populations and the Solar Neighborhood,” in Allen’s Astrophysical Quantities, 4th ed. A. N. Cox ed., Springer-Verlag, NY (2000), Chap. 19.

8. J. J. Binney, W. Dehnen, N. Houk, C. A. Murray, and M. J. Preston, “Kinematics of Main Sequence Stars from Hipparcos Data,” Proceedings of the ESA Symposium Hipparcos Venice
, SP-402, Venice, Italy, 13-15 May 1997, pp. 473-477 (July, 1997).

9. G. L. Matloff, “Olaf Stapledon and Conscious Stars: Philosophy or Science?”, JBIS, 65, 5-6 (2012).

10. E. Chaisson and S. McMillan, Astronomy Today, 6th ed., Pearson-Addison/Wesley, San Francisco, CA (2008), Chap. 19.

11. R. S. DeSimone, X. Wu, and S. Tremaine, ”The Stellar Velocity Distribution of the Stellar Neighborhood”, Monthly Notices of the Royal Astronomical Society, 350, 627-643 (2004).

12. G. L. Matloff and C Bangs, Starlight, Starbright: Are Stars Conscious?, Curtis Press, UK (2015).

13. G. L. Matloff, “The Non-Locality of Parenago’s Discontinuity and Universal Self Organization”, IAA-FSE-15-06-03. Presented at 9th IAA Symposium on the Future of Space Exploration, Turin, Italy, July 7-9, 2015. Published in Conference Proceedings.

14. R. L. Branham, “The Kinematics and Velocity Ellipsoid of GIII Stars,” Revisita Mexicana de Astronomia y Astrofisica, 47, 197-209 (2011).

15. K. Foyle, H.-W. Rix, C. Dobbs, A. Leroy, and F. Walter, “Observational Evidence Against Long-Lived Spiral Arms in Galaxies,” Astrophysical Journal, 735 (2), Article ID = 101 (2011), arXiv: 1105.5141 [astro-ph.CO].

16. F. Namouni, “On the Flaring of Jet-Sustaining Accretion Disks”, Astrophysical Journal, 659, 1505-1510 (2007).

17. I. O’Neill, “Sun May Blast Two Jets of Plasma into Interstellar Space”, news.discovery.com, (March 4, 2015). Also see “A New View of the Solar System: Astrophysical Jets Driven by the Sun”, bu.edu (February 19, 2015).

18. D. Kaiser, How the Hippies Saved Physics, Norton, NY (2011).

19. E. W. Davis, “Teleportation: Mind and Intelligence”, Report to the US Air Force Future Technology Branch, Future Concepts and Transformation Division Workshop, Mitre Corporation, McLean VA (Oct. 21, 2005).

20. E. W. Davis, “Teleportation Physics Study,” Final Report AFRL-PR-ED-TR-2003-0034, Air Force Research Laboratory, Air Force Materiel Command, Edwards AFB, CA (2004): https://www.fas.org/sgp/eprint/teleport.pdf