NEOWISE: New Data Release, Implications

The Wide-field Infrared Survey Explorer (WISE) has been featured often in these pages, usually in terms of brown dwarfs and the possibility of uncovering a small star or brown dwarf closer than Proxima Centauri. But while we still have no evidence of such, we do have abundant data on brown dwarfs, as well as a useful compendium of objects that come close to the Earth. For WISE, launched in 2009 and placed into hibernation in 2011 upon completion of its primary mission, was reactivated in 2013 as NEOWISE. The goal is now the observation of asteroids and comets both near and far by way of characterizing their size and composition. Amy Mainzer (JPL), NEOWISE principal investigator, points to the mission's success: "NEOWISE continues to expand our catalog and knowledge of these elusive and important objects. In total, NEOWISE has now characterized sizes and reflectivities of over 1,300 near-Earth objects since the spacecraft was launched, offering an invaluable resource for understanding...

read more

Holographic Sails for Project Starshot? — Homage to Bob Forward

One of the reasons I described Greg Matloff as the 'renaissance man of interstellar studies' in my Centauri Dreams book is the continuing stream of ingenious ideas that he develops and delivers through papers and conference presentations. I found the holographic sail concept below fascinating, and would have referenced Bob Forward myself if Greg hadn't already done it in the text. These two must have been great to hear in conversation! Read on to learn how Greg, a physicist at New York City College of Technology (CUNY) came up with the idea, a process that deftly blended science and art and may provide solutions to some of the more intractable problems posed by Breakthrough Starshot. The author of The Starflight Handbook among many other books (volumes whose pages have often been graced by the artwork of the gifted C Bangs), Greg has been inspiring this writer since 1989. By Greg Matloff It was perhaps inevitable that I would be asked to serve on the Advisor's Board of Yuri Milner's...

read more

Identifying the Sun’s Siblings

With TESS going into a 60-day period of calibration and testing, I'll turn this morning to a different kind of survey. GALAH is an acronym for Galactic Archaeology, a term I've generally associated with so-called Dysonian SETI, where data is mined in a search for signs of advanced engineering or any anomalies that could signify an extraterrestrial civilization at work. But GALAH has a different object: It has examined some 340,000 stars enroute to 1 million. A just published paper on GALAH states the goal succinctly: The overarching goal of the GALAH survey is to acquire high-resolution spectra of a million stars for chemical tagging, in order to investigate the assembly history of the Galaxy. The survey was launched in 2013 as a deep study of galactic formation and evolution, using the HERMES spectrograph at the Australian Astronomical Observatory's 3.9-meter Anglo-Australian Telescope near Coonabarabran, NSW. Now coming online is a major data release, the second from GALAH, that...

read more

Civilization Before Homo Sapiens?

My doctor is a long-time friend who always stops during my annual physical to ask about what's going on in the hunt for exoplanets. Last week he surprised me when, after I had described ways of analyzing a transiting planet's atmosphere, he asked whether planets could give rise to civilizations in different epochs. Why just one, in other words, given that homo sapiens has only been around for several hundred thousand years? Our technological civilization is a very recent, and to this point a short-lived phenomenon. Were there others? I was startled because Adam Frank (University of Rochester) and Gavin Schmidt (NASA Goddard Institute for Space Studies) have recently raised a stir with a paper on what they call the 'Silurian Hypothesis,' the name deriving from a Doctor Who TV episode referencing intelligent reptiles called Silurians who come to life when accidentally awakened. As the authors point out in their paper: We are not however suggesting that intelligent reptiles actually...

read more

A Deeper Look at TESS

The launch of TESS aboard a SpaceX Falcon 9 looks to be on track for Wednesday after yesterday's delay, which the company attributed to the need for "additional GNC [guidance, navigation and control] analysis." So we wait just a bit more, knowing that the payoff justifies the caution. We should be identifying planets in the thousands, and around bright, nearby stars. Standing down today to conduct additional GNC analysis, and teams are now working towards a targeted launch of @NASA_TESS on Wednesday, April 18.— SpaceX (@SpaceX) April 16, 2018 Principal investigator George Ricker and team have been through the process of designing, building and launching a mission before. It was in 2000 that NASA launched the MIT-built High Energy Transient Explorer 2, or HETE-2, that studied gamma-ray bursts for seven years in Earth orbit. A key technology for HETE-2 was the CCD -- charge-coupled device -- which allowed the satellite's optical and X-ray cameras to record bursts in electronic...

read more

Go TESS

"I always get the shakes before a drop," wrote Robert Heinlein, the words being those of protagonist Johnny Rico in his novel Starship Troopers. I thought of them again this morning because while I don't tend to get the 'shakes,' I do tend to get nervous before a major launch, and that's what we have today. The image below comes from the TESS mission Twitter account @NASA_TESS (https://twitter.com/NASA_TESS) in a shot just posted as I write. Launch is scheduled for 1832 Eastern time (2332 UTC) and can be seen here. The launch vehicle is a SpaceX Falcon 9, lifting off from Cape Canaveral. Here's a bit of NASA's latest statement: TESS is NASA's next step in the search for planets outside of our solar system, known as exoplanets, including those that could support life. The mission is expected to catalog thousands of planet candidates and vastly increase the current number of known exoplanets. TESS will find the most promising exoplanets orbiting relatively nearby stars, giving future...

read more

The polis of Artemis on the Moon

Can Andy Weir's Artemis, the setting for his new novel of the same name, be best described as a city or a town? Or is it better to think of it, as Ioannis Kokkinidis does in the essay that follows, as a 'polis'? The ancient Greek term carries through the centuries to inform Ioannis' musings on Weir's creation, as he examines Artemis, a tourist destination like no other, from a deeply international perspective. Well known for his attempt to keep the science of The Martian accurate, Weir set a high bar, one to which Artemis will invariably be compared. Ioannis Kokkinidis is a resident of Fresno, CA with an abiding interest in deep space. He holds a Master of Science in Agricultural Engineering from the Department of Natural Resources Management and Agricultural Engineering of the Agricultural University of Athens. He went on to obtain a Mastère Spécialisé Systèmes d’informations localisées pour l’aménagement des territoires (SILAT) from AgroParisTech and AgroMontpellier and a PhD in...

read more

Breakthrough Discuss Streaming Live

I don't usually reproduce news releases here, but this one is of unusual interest given that I am both a strong supporter of Breakthrough Starshot and a partisan for getting academic conferences available through live streaming. Breakthrough Discuss begins today and its sessions will be well worth your time, given the array of distinguished speakers and the tight attention to matters interstellar. The third annual Breakthrough Discuss scientific conference (https://breakthroughinitiatives.org/events/discussconference2018), which will bring together leading astrobiologists, astronomers, engineers, and astrophysicists to advance discussion around recent discoveries of potential life in the universe and novel ideas for space exploration, will be held on Thursday, April 12, and Friday, April 13, and full sessions will be available for live viewing on YouTube. The two days of discussions will focus on "Alien Life: Diversity in the Universe," with sessions discussing the search for life in...

read more

Disk Imagery from Nearby Young Stars

Here's an interesting situation: Around a star designated GSC 07396-00759, a member of a multiple star system, astronomers have found an edge-on disk. Such disks are helpful ways of studying planetary evolution, as we're looking at gas, dust and planetesimals that represent a planetary system in the process of formation. But at GSC 07396-00759, the disk is more evolved than the gas-rich disk around the T Tauri star in the same system. In other words, we have two stars evidently of the same age whose disks show a different evolutionary pace. Elena Sissa (INAF-Osservatorio Astronomico di Padova) is lead author of a new paper on this find, in press at Astronomy & Astrophysics. The paper puts the matter this way: Even if there is no "smoking gun" proof, the system characteristics all together tend to favor an evolved/debris disk nature for GSC 07396-00759 over a primordial/gas-rich disk. If confirmed, this is a very interesting discovery since this star and V4046 Sgr form a coeval...

read more

Exoplanets: Accelerating the Pace of Discovery

As we await the launch of the Transiting Exoplanet Survey Satellite, I want to pause this morning to remind everyone of another significant mission: CHEOPS (CHaracterising ExOPlanet Satellite). The decade ahead is going to be an exciting one for exoplanet discovery, given that we have TESS about ready to go, JWST in the pipeline despite its problems, and CHEOPS expected to launch in 2019. Eleven European nations are involved in CHEOPS, a European Space Agency 'S-class' mission that will study exoplanetary transits. Image: Artist's impression of CHEOPS at work. Credit: ESA. In 2026, we can look forward to ESA's PLAnetary Transits and Oscillations of stars (PLATO) mission, which will study up to a million stars in search of planetary transits, with the emphasis on rocky planets in the habitable zone. In 2028, we have the ARIEL mission (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) to anticipate (see ARIEL: Focus on Exoplanet Atmospheres). What a run of space-based...

read more

A Triton Lander Mission

What would be our next step in the exploration of the outer system once New Horizons has visited one or more Kuiper Belt objects (KBOs)? One intriguing target with a nearby ice giant to recommend it is Triton, Neptune's unusual moon, which was imaged up close only once, by Voyager 2 in 1989. The views were spectacular but at the time of the encounter, most of Triton's northern hemisphere remained unseen because it was in darkness. Only one hemisphere showed up clearly as the spacecraft passed the moon at a distance of 40,000 kilometers. Our next visit should tell us much more, but we're still working out the concept. Thus Steven Oleson's Phase II grant from NASA's Innovative Advanced Concepts (NIAC) office. Oleson (NASA GRC) calls the idea Triton Hopper. In his Phase I study, he identified the various risks of the mission, analyzing its performance and its ability to collect propellant. For Triton Hopper -- moving from point to point -- would rely on a radioisotope engine that would...

read more

Laser Beaming and Infrastructure

Looking at John Brophy's Phase II NIAC award reminds us how useful the two-step process can be at clarifying and re-configuring deep space concepts. Brophy (Jet Propulsion Laboratory) had gone to work in Phase I with a study called "A Breakthrough Propulsion Architecture for Interstellar Precursor Missions." The work studied a lithium-fueled ion thruster with a specific impulse of 58,000 seconds. If that didn't get your attention, consider that the Dawn spacecraft's ISP is 3,000 seconds, and think about what we might be able to do with that higher figure. I think about ideas like this in terms of infrastructure. The relation to interstellar flight is this: While we may well get robotic nano-probes off on interstellar missions (think Breakthrough Starshot) some time this century, the idea of human expansion into the cosmos awaits the growth of our civilization into the rest of the Solar System. Along the way, we will learn the huge lessons of closed-loop life support, means of...

read more

Tightening the Beam: Correspondence on PROCSIMA

Yesterday's post on PROCSIMA (Photon-paRticle Optically Coupled Soliton Interstellar Mission Accelerator) has been drawing a good deal of comment, and I wanted to dig deeper into the concept this morning by presenting some correspondence between plasma physicist Jim Benford, a familiar face on Centauri Dreams, and PROCSIMA's creator, Chris Limbach (Texas A&M Engineering Experiment Station). As we saw yesterday, PROCSIMA goes to work on the problem of beam spread in both laser and particle beam propulsion concepts. In my own email exchange with Dr. Limbach, he took note of the comments to yesterday's Centauri Dreams article, with a useful nod to a concept called 'optical tweezers' that may be helpful. So let me start with his message of April 4, excerpting directly from the text: I took a quick glance at the comments, and I see that the laser guiding (i.e. waveguide) effect is fairly well understood, but the guiding of the particles is less clear. I admit this is the less intuitive...

read more

PROCSIMA: Wedding Two Beam Concepts

The name Proxima will always have resonance with interstellar theorists given that our nearest target -- and one with a potentially life-bearing planet at that -- is Proxima Centauri. Thus an acronym with the same pronunciation is bound to catch the attention. PROCSIMA stands for Photon-paRticle Optically Coupled Soliton Interstellar Mission Accelerator, one of 25 early-stage technology proposals selected for Phase I funding by the NASA Innovative Advanced Concepts (NIAC) office. A number of Phase II proposals selected for funding was also announced. These awards are always fascinating to watch because they're chosen from a host of bleeding edge ideas, helping us keep a finger on the pulse of deep space thinking even if many of them end with their Phase I funding, $125,000 over nine months to produce an initial definition and analysis. Should the results be encouraging, Phase II funding becomes a possibility, ramping the money up to $500,000 over two years to encourage further...

read more

2001: A Space Odyssey – 50 Years Later

Fifty years ago today, 2001: A Space Odyssey was all the buzz, and I was preparing to see it within days on a spectacular screen at the Loew's State Theater in St. Louis. The memory of that first viewing will always be bright, but now we have seasoned perspective from Centauri Dreams regular Al Jackson, working with Bob Mahoney and Jon Rogers, to put the film in perspective. The author of numerous scientific papers, Al's service to the space program included his time on the Lunar Module Simulator for Apollo, described below, and his many years at Johnson Space Center, mostly for Lockheed working the Shuttle and ISS programs. But let me get to Al's foreword -- I'll introduce Bob Mahoney and Jon Rogers within the text in the caption to their photos. Interest in 2001 is as robust as ever -- be aware that a new 513-page book about the film is about to be published. It's Michael Benson's Space Odyssey: Stanley Kubrick, Arthur C. Clarke, and the Making of a Masterpiece. Let's now return to...

read more

Imaging a Centauri Planet

Last December I mentioned the ongoing work at the European Southern Observatory's Very Large Telescope to modify an instrument called VISIR (VLT Imager and Spectrometer for the InfraRed). Breakthrough Initiatives, through its Breakthrough Watch program, is working with the ESO's NEAR program (New Earths in the Alpha cen Region) to improve the instrument's contrast and sensitivity, the goal being the detection of a habitable zone planet at Alpha Centauri. Exciting stuff indeed, especially given the magnitude of the challenge. After all, we are dealing with a tight binary, with the two stars closing to within 11 AU in their 79.9 year orbit about a common center (think of a K-class star at about Saturn's distance). The binary's orbital eccentricity can separate the stars by about 35 AU at their most distant. The latest figure I've seen for the distance between Centauri A/B and Proxima Centauri is about 13,000 AU. In an ESO blog post that Centauri Dreams reader Harry Ray passed along,...

read more

ARIEL: Focus on Exoplanet Atmospheres

Given Centauri Dreams's interest in exoplanet studies, it's no surprise that when I write about the James Webb Space Telescope, it's usually to fit the observatory into the overall study of other stellar systems. But of course JWST has been conceived to study everything from the earliest stars and galaxies to the ongoing birth of stars out of massive clouds of dust, not to mention objects within our own Solar System. JWST also offers us a real chance to probe exoplanet atmospheres around nearby M-dwarfs, but it is certainly not a dedicated exoplanet mission. So while we hope for a successful launch in 2020, according to the evolving schedule, and look forward to finding plenty of JWST targets with the upcoming Transiting Exoplanet Survey Satellite (TESS), let's have a look at a new mission from the European Space Agency with a tight exoplanet focus. The Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) has just been selected as an ESA science mission scheduled for...

read more

Getting JWST Aloft

No one said this was going to be easy. Delays involving the James Webb Space Telescope are frustrating, with NASA now talking about a launch in mid-2020 instead of next year, and the uncertain prospect of a great deal of further testing and new expenditures that could run the project over budget, necessitating further congressional approval. It's hard to look back at the original Webb projections without wincing. When first proposed, estimates on the space observatory ran up to $3.5 billion, a hefty price tag indeed, though the science payoff looked to be immense. It was in 2011 that a figure of $8 billion emerged; the project now has a Congressionally-mandated cost cap of $8.8 billion. And now, looking forward, we have Thomas Zurbuchen, speaking for NASA's Science Mission Directorate, explicitly saying "We don't really fully know what the exact cost will be…" Image: Illustration of NASA's James Webb Space Telescope. Credit: NASA. Projects this big invariably take us into the...

read more

TRAPPIST-1: An Abundance of Water?

Too much water helps planetary habitability not one bit. And while we find the availability of surface water a useful way of describing a potentially habitable world, we're learning that some planets may have water in such abundance that life may never have the chance to emerge. It would be a shame if the numerous worlds orbiting TRAPPIST-1 fell into this scenario, but a multidisciplinary team from Arizona State University is making a strong case for the prospect. What's wrong with water? Let Natalie Hinkel (Vanderbilt University) explain. Hinkel worked with ASU's Cayman Unterborn, Steven Desch and Alejandro Lorenzo on the question of water composition in these worlds. Coleridge's "Rime of the Ancient Mariner" comes to mind -- "Water, water, every where / Nor any drop to drink." But in this case, there is plenty to drink, which is precisely the problem. Says Hinkel: "We typically think having liquid water on a planet as a way to start life, since life, as we know it on Earth, is...

read more

Charter

In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For many years this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image courtesy of Marco Lorenzi).

Now Reading

Recent Posts

On Comments

If you'd like to submit a comment for possible publication on Centauri Dreams, I will be glad to consider it. The primary criterion is that comments contribute meaningfully to the debate. Among other criteria for selection: Comments must be on topic, directly related to the post in question, must use appropriate language, and must not be abusive to others. Civility counts. In addition, a valid email address is required for a comment to be considered. Centauri Dreams is emphatically not a soapbox for political or religious views submitted by individuals or organizations. A long form of the policy can be viewed on the Administrative page. The short form is this: If your comment is not on topic and respectful to others, I'm probably not going to run it.

Follow with RSS or E-Mail

RSS
Follow by Email

Follow by E-Mail

Get new posts by email:

Advanced Propulsion Research

Beginning and End

Archives