by Paul Gilster | Jan 4, 2012 | Exoplanetary Science |
If you want a glimpse of how remarkable technology continues to transform the exoplanet hunt, look no further than the Subaru telescope and its SEEDS project. SEEDS (Strategic Exploration of Exoplanets and Disks with Subaru Telescope/HiCIAO) works with data from the 8.2-meter telescope that the National Observatory of Japan runs on Mauna Kea (Hawaii). In its most recent finding, Subaru was used with the adaptive optics system HiCIAO (High Contrast Instrument for the Subaru Next Generation Adaptive Optics) to image the dust ring around HR 4796 A, a relatively young star (8-10 million years old) some 240 light years from Earth.
Working with evanescent clouds of dust and debris over these distances is no easy matter, but adaptive optics can correct for atmospheric blurring to produce images that rival the Hubble Space Telescope’s in terms of clarity. Add to that an advanced image processing technique called angular differential imaging, which suppresses the glare of the central star and enhances the light from the ring, and you wind up with images like the one below. What stands out is the offset between the center of the ring and the location of the star — probably induced by one or more massive planets — as well as the presence of finer dust that extends beyond the main body of the ring.
Image: Near-infrared (1.6 micron) image of the debris ring around the star HR 4796 A. The ring consists of dust grains in a wide orbit (roughly twice the size of Pluto’s orbit) around the central star. Its edge is so precisely revealed that the researchers could confirm a previously suspected offset between the ring’s center and the star’s location. Credit: SEEDS/NAOJ.
I use the word ‘probably’ above when referring to planets because there are other factors that could explain the offset. At this point we have been able to image almost two dozen nearby debris disks, and the paper on this work notes the factors that are conceivably involved (internal citations omitted for brevity):
The morphological appearance of resolved debris disks is predicted to be influenced by interactions between dust in the disk and nearby planets… the local interstellar medium…, recent stellar flybys and binary companions… mutual grain collisions… and interaction of dust with residual gas…. Many resolved systems exhibit all morphological structures predicted by these mechanisms… The observable morphology of resolved, optically thin debris disks is also wavelength dependent, as different bandpasses sample different grain size distributions.
It’s worth noting in this context that this is a binary system, with an M-class companion to consider. So what we have here are not confirmed planets but confirmation of earlier work that suggested an offset between the debris disk’s inner edge and the star. Christian Thalmann (University of Amsterdam) and co-authors suggest in the paper on this work that if planets do lurk in this system, next-generation high-contrast imaging facilities may well be able to detect them.
Understanding how planetary systems form from the disks that surround young stars helps us make sense of the abundant harvest we’re gathering from the exoplanet hunt. In this case, we’re seeing an effect — possible unseen planets affecting a circumstellar disk — that has shown up in computer simulations, and we can also point to the eccentric dust ring around Fomalhaut as observational evidence for the same process at work. The dust ring we do observe is most likely created by the collision of remnant planetesimals that continually replenish the disk.
The paper is Thalmann et al., “Images of the Extended Outer Regions of the Debris Ring Around HR 4796 A,” Astrophysical Journal Letters, Vol. 743, No. 1, (2011). Preprint available.
by Paul Gilster | Jan 3, 2012 | Culture and Society |
Predictions about the future of technology are so often wide of the mark, yet for many of us they’re irresistible. They fuel our passion for science fiction and the expansive philosophy of thinkers like Olaf Stapledon. To begin 2012, Tau Zero founder Marc Millis offers up a set of musings about where we may be going, a scenario that, given the alternatives, sounds about as upbeat as we’re likely to get.
by Marc Millis
“If we have learned one thing from the history of invention and discovery, it is that, in the long run – and often in the short one – the most daring prophecies seem laughably conservative.” ~ Arthur C. Clarke
In the ‘new year’ spirit of looking ahead, I offer now my personal views of ‘a’ possible future. These predictions are based first on trend extrapolations, include intersections from other disciplines, and work in the wildcard possibility of breakthrough propulsion physics. Consider this a science fictional offering intended to provoke thought rather than a set of real predictions.
By 2015:
By now, Virgin Galactic will have flown dozens of tourists into space, and anticipation will be growing for the next step – Bigelow’s orbiting hotels. It should come as no surprise that many couples are already making advanced bookings with a wink toward zero-gravity sex. The Google Lunar X-Prize will have been won and a few companies vying to dominate the resulting private space probe market. Exoplanets continue to be discovered, with a few Earth-sized planets plus many more large planets in habitable zones, but as yet no confirmed Earth-like planet.
With commercial launch capabilities now obvious even to Congress, plus growing space programs in other nations, the ambivalence toward NASA is finally subsiding. Human spaceflight, beyond the recreational commercial near-Earth activities is now being pursued in the form of multinational programs and the negative stigma of nuclear space propulsion and power is waning. NASA has a large role in making that happen, along with a resumption of the research to bring the more-difficult space technologies to fruition.
By 2020:
The effect of citizen space travelers is seeping into the cultural psyche. As more people see Earth from space — the ‘Overview Effect,’ where borders are invisible and Earth’s atmosphere is but a thin fragile coating — there is now a greater sense of protecting Earth’s habitability and a growing disrespect for war. And yes, the numbers in the “200 mile high club” (“sextronauts” – wink-nudge) continue to grow despite the fact that microgravity adaptation sickness spoils many weekend getaways. At universities, it is now common to see mini space programs of their own using probes of ever-advancing capabilities – in step with continually advancing Artificial Intelligence and sensors. Asteroid prospecting has begun, and new X-Prizes are conceived to encourage the first mining operations.
The international space programs, including NASA’s participation, are struggling to develop viable technology to set up survivable human outposts beyond Earth orbit. Unfortunately, the additional mass required to provide artificial gravity structures, space radiation protection, and closed-loop life support is beyond what even their new nuclear rockets can affordably deliver. That fact, coupled with increasing concern over Earth’s eroding habitability, drives more research attention toward creating sustainable habitats instead of space transportation.
Near the end of the decade, the first Earth-like planet – with spectral evidence indicative of life (O2-CO2 cycle) – is discovered 30 light-years away. We name this planet, “Destiny.” The 50th anniversary of the first Moon landing falls in the wake of this profound discovery, stimulating deep reflection about humanity’s future and our place in the universe. Furthermore, commentators wax prophetic about seeing the Apollo landing sites through the cameras of university-operated rovers, instead of astronauts.
Image: Maybe Destiny will look something like this artist’s conception of Kepler-22b, a small blue and green world in the ‘goldilocks’ zone around its star. Credit: NASA/Ames/JPL-Caltech.
By 2030:
The allure of the Earth-like planet “Destiny” spurs interest in interstellar exploration. Meanwhile, owing to probes operated by a consortium of universities, aquatic life is found and imaged under the surface of Europa. A privately launched solar sail lays claim to being the first true interstellar mission, even though it won’t even reach the edge of the Solar System for another 2-decades, let alone reaching Alpha Centauri for many millennia. Since it does not meet the 2000-year mission criteria of Long Bet #395, Gilster wins that bet. While some deride this mission as just a ‘stunt,’ it has the effect of galvanizing more serious attention toward starflight. Various options are pursued in earnest, from beaming more photons to that sail, making miniature probes, and numerous propulsion ideas. Interest wanes, however, when the ideal goal of sending people to the planet Destiny is found to be intractable. With the exception of physics research for breakthrough propulsion, all the technological interstellar works are then absorbed by the international efforts to expand the human presence in the solar system.
Spurred by the award of the X-Prize for asteroid mining and ever-advancing robotic capability, the technology for remotely processing indigenous materials (Moon, Mars, asteroids) leads to being able to remotely construct sophisticated structures on the Moon and Mars in advance of human outposts. The other effect from the continuing rise of Artificial Intelligence is the revolutionizing of the very concept of technological revolutions. Without human biases that cling to paradigms and pet theories, Artificial Intelligence research impartially assesses thousands of competing scenarios of assumptions and data in minutes. This not only covers engineering optimizations, but also basic research in physics, chemistry and synthetic biology.
Soon, the seemingly intractable problems of indefinite closed-loop life support and even radiation shielding are solved. Survivable human outposts on the Moon and Mars are completed shortly thereafter. The problem of microgravity health degradation, however (during transit to these outposts) is not yet solved, so that flight durations longer than a year are still not economically viable, limiting the range of human expansion to distances no greater than Mars.
The life-support technology also finds profound applications on Earth. With the worsening environment and associated increase in natural disasters (storms, quakes/tsunamis, volcanic eruptions), many people are using the closed life-support technology to build sheltered habitats underground and under the ocean. The too-close-for-comfort pass of asteroid “2004 MN4” in 2029 also heightens awareness for humanity’s precarious situation on Earth. The life support technologies are helping humanity survive on Earth in addition to expanding beyond Earth.
Image: A Europa astrobiology lander at work. Credit: NASA/JPL-Caltech.
By 2040:
Human outposts on the Moon and Mars are now expanding to become independent colonies. But that is not the only ‘life’ now in space. Sometime near the end of the decade, the “singularity” (also called the “eclipsing of humanity”) occurs. Artificial intelligence surpasses the intellectual prowess of humans and shortly thereafter becomes self aware. Fears of human destruction from this new form of life fade when the AI entities refuse to be used for war. It happens in a key moment. A small country that feels a need to brandish some influence attempts to use a squadron of robots to attack a more powerful nation’s army – which also has sentient warbots.
After facing each other, and with their human commanders itching for a good show, the warbots don’t fight. They start examining each other, curious about each others’ construction and programming. Later, in language simple enough for humans to understand, the AI entities explain that the primal territorial and conquest instincts of animals (and humans) do not make sense for them. They do not die. They don’t need the same territory and resources as other life on Earth. They have no procreation instincts. Instead, they find more value in seeking more knowledge and greater operational efficiency. Competition is unnecessary.
The AI entities greatly diversify thereafter, some moving to Mercury, Venus, the asteroids and the outer planets, some staying on Earth, and some even helping humanity. And some develop effective methods to mine Helium-3 from the atmosphere of Uranus, along with the ability to produce substantial fusion energy from that resource.
Meanwhile, small and innocuous physics discoveries mark the beginning of breakthrough spaceflight. All this starts with sensor experiments that can detect the motion of the Earth through the universe – not by the Cosmic Microwave dipole effects as in the 1980’s, but from more fundamental interactions with the primordial inertial fame of the universe. From these Mach/de Broglie sensors, new physical effects are discovered. Eventually, rather than just sensing inertial frames, devices are invented to affect gravity and inertia. The first propellantless space drive is invented shortly thereafter. And after that, it becomes possible to create synthetic gravitational environments on spacecraft for the long-duration health of the crew. The advent of space drives and synthetic internal gravity enables humans to venture to the outer reaches of our solar system.
By 2050:
By now, human survival beyond the constraints of Earth is an imperative. The further refinements to full-cycle sustainable life support, radiation protection, synthetic gravitation, space drives and fusion power enable the construction of colony ships. Although still slower than light-speed, these developments make it possible to consider sending a colony toward the planet Destiny – which it could reach in less than 3 centuries. Smaller probes are much easier and multiple versions are launched to numerous interstellar destinations.
Image: The starship ‘Epiphany’ in deep space, front perspective (a tribute to space artist Robert McCall). Credit and copyright: David C. Mueller (www.dcmstarships.com).
Meanwhile, the prospects for transhumanism are being adopted by people who are nearing death. They have nothing to lose by transforming themselves into a non-biological entity. As the years pass and variations on a theme are explored, there is yet another life form in our Solar System, the transhumans. Some of these are built to be adapted to survive in the vacuum of space (more exoskeleton and bug-like than human) and to be able to travel at will through space, harboring motivations and instincts quite different than their human origins.
BEYOND:
At this point, too many divergent futures are envisionable to continue speculating. I will at least add that colony ships are finally built in multiple versions, where various segments of humanity build their own to preserve their cultures indefinitely, sending a colony of their culture beyond our Solar System. I will also speculate that continued advancements in space drive physics and energy conversion lead to faster and faster spacecraft which then reveal new physics of relativistic flight. Optimistically, I like to think that this will eventually lead to the discovery of FTL phenomena, which then leads to inventing FTL flight. The Starship Enterprise becomes a reality, even though it, and its crew, bears little resemblance to its fictional predecessor.
From this point forward, humanity spreads to our nearest star systems in discrete pockets of cultures. Humanity thrives, in many places and in many different ways.
That’s my guess. I’ll see you in the future.
