Centauri Dreams

Centauri Dreams


Imagining and Planning Interstellar Exploration

Link: www.centauri-dreams.org


Enceladus Lights Up Saturn’s Inner Moons

Sep 19, 2019


In his wonderful account of the rocket that never was (Project Orion: The True Story of the Atomic Spaceship, 2002), George Dyson discusses his father’s thoughts on taking the craft to the moons of Saturn. Freeman Dyson and other Orion colleagues wanted to land on a moon to pick up propellant, but thought the moons […]

eVscope: Supporting Lucy Mission to Jupiter Trojans

Sep 18, 2019


Spreading scientific investigation beyond the research lab and astronomical observatory is what citizen science is all about. As we saw yesterday, projects like ExoClock are enlisting amateur volunteers to time exoplanet transits in support of the upcoming ARIEL mission. Also among such projects discussed at the ongoing EPSC-DPS joint meeting in Geneva is the eVscope […]

Introducing ExoClock: An Open Call for Participation

Sep 17, 2019


Ongoing in Geneva is the joint meeting of the European Planetary Science Congress and the Division for Planetary Sciences of the American Astronomical Society. We can abbreviate the whole thing as EPSC-DPS 2019, and you can read more about it here. We’ll track several stories here as they develop, but I notice that the European […]

Could We Send a Probe to C/2019 Q4 (Borisov)?

Sep 16, 2019


The arrival of an apparent interstellar visitor, the comet now designated C/2019 Q4 (Borisov), invariably calls to mind the all too swift passage of ‘Oumuamua through our skies in 2017. Detected 40 days after perihelion, the object was headed out of the Solar system when discovered, making observation time limited and the prospects of visiting […]

The Human Adventure is Just Beginning: Alien and Star Trek: The Motion Picture at 40

Sep 13, 2019


Larry Klaes loves science fiction movies. Those of you who have read his deep dives into such films as Forbidden Planet, Avatar or The Thing from Another World can understand why I think of Larry as the Robert Osborne of the SF movie (if you don’t know who Robert Osborne was, then you’re not as […]

C/2019 Q4 (Borisov): A Likely Interstellar Comet

Sep 12, 2019


What appears to be an interstellar comet is heading into the Solar System, with perihelion likely on December 10 of this year, a date that could change as orbital parameters continue to be firmed up. The natural comparison is with ‘Oumuamua, first discovered two years ago and now well on its way out of the […]

Water Vapor Detection on a ‘Super-Earth’

Sep 11, 2019


We’re beginning to probe the atmospheres of planets other than gas giants, a step forward that the next generation of space- and ground-based instruments will only accelerate. This morning we have word that the habitable zone ‘super-Earth’ eight times as massive as Earth orbiting the star K2-18 has been found to have water vapor in […]

A New Explanation for Lakes on Titan

Sep 10, 2019


The vast amount of data returned to Earth from the Cassini mission continues to pay off with new research angles, a process that will continue for years to come. Today we learn of a possible explanation for an odd feature of some methane-filled lakes on Saturn’s moon Titan. As viewed in Cassini radar data, we […]

Internal Pressure and Planet Formation

Sep 9, 2019


Our thinking on how planetary systems form includes the accretion of rocky bodies within a disk surrounding a young star, and we’re examining such disks in numerous systems, such as the well studied Beta Pictoris. But the idea of accretion leaves many issues unsettled, such as what happens when large rocky bodies collide in the […]

Tales from Iceland: Extreme Solar Systems IV

Sep 6, 2019


Reykjavik is an old haunt of mine, a favorite place to which I have not returned in all too long. I was delighted, then, to hear from Angelle Tanner, who in August attended the Extreme Solar Systems IV conference there. I had the pleasure of getting to know Dr. Tanner in Knoxville when we both […]

Looking for Lurkers: A New Way to do SETI

Sep 4, 2019


SETI, the Search for Extraterrestrial Intelligence, has kept its focus on the stars, through examination of electromagnetic wavelengths from optical to radio signals. But Jim Benford has been advocating that we consider near-Earth objects as potential SETI targets, prompted by Ronald Bracewell’s thoughts in a 1960 paper advancing the ‘sentinel hypothesis.’ A Bracewell probe could […]

Spectroscopic Evidence of a Possible Exomoon

Sep 3, 2019


It shouldn’t surprise us that first discoveries can be extreme. Consider that the first main sequence exoplanets we detected were ‘hot Jupiters.’ Nobody expected these (unless you discount John Barnes and Buzz Aldrin in Encounter with Tiber, and Greg Matloff, who advised them — see Probing Ultrahot Jupiters — but a radial velocity detection is […]

Is Enceladus Prebiotic?

Aug 30, 2019


Centauri Dreams regular Alex Tolley here examines a new paper with a novel take on Saturn’s moon Enceladus. Tempting us with its geysers and the organic compounds Cassini detected in their spray, Enceladus offers the prospect of life within its internal ocean. But are there other explanations for what we see, pointing to what may […]

A Major Step for the James Webb Space Telescope

Aug 29, 2019


The James Webb Space Telescope has been assembled for the first time, meaning its two halves — the spacecraft and the telescope — have been connected, following up earlier testing in which the two parts were temporarily connected by ground wiring. The latter took place almost a year ago, in September of 2018, allowing spacecraft […]

HR 5183 b: Pushing Radial Velocity Techniques Deeper into a Stellar System

Aug 28, 2019


Radial velocity methods for detecting exoplanets keep improving. We’ve gone from the first main sequence star with a planet (51 Pegasi b) in 1995 to over 450 planets detected with RV, a technique that traces minute variations in starlight as a star nudges closer, then further from us as it is tugged by a planet. […]

Upwelling Oceans: Modeling Exoplanet Habitability

Aug 27, 2019


We usually talk about habitability in binary form — either a planet is habitable or it is not, defining the matter with a ‘habitable zone’ in which liquid water could exist on the surface. Earth is, of course, the gold standard, for we haven’t detected life on any other world. But it is conceivable that […]

JUICE: Targeting Three Icy Moons

Aug 26, 2019


Because Europa Clipper has been on my mind, what with the confirmation of its next mission phase (see Europa Clipper Moves to Next Stage), we need to continue to keep the mission in context. What is playing out is a deepening of our initial reconnaissance of the Jovian system, and the JUICE mission (Jupiter Icy […]

Going Deep into Jupiter’s Storms

Aug 23, 2019


Having just looked at events that may have shaped Jupiter’s core, it seems a good time to note the new Hubble image of the planet, taken on June 27, 2019. A couple of things to focus on in the image below: The vast anticyclonic storm we call the Great Red Spot, about the diameter of […]

Giant Jovian Impact Could Explain Juno Data

Aug 22, 2019


Impacts seem to have run rampant in the early Solar System, to judge from what we keep uncovering as we survey today’s evidence. The Moon is widely considered to be the result of Earth’s impact with a Mars-class object, while Mercury’s big iron core may show what happens when a larger world is stripped of […]

Europa Clipper Moves to Next Stage

Aug 21, 2019


Europa Clipper stays on my mind, with the intent of digging deeper into the spacecraft as development moves forward. We are talking about a craft that is by necessity radiation-tolerant as it will make a series of close flybys of Europa during its long orbit of Jupiter. 45 such flybys are in the cards, at […]

LHS 3844b: Rocky World’s Atmosphere Probed

Aug 20, 2019


These days we have a keen interest in small red dwarf stars (M-dwarfs) not only because they’re ideal for study, with deep transits of worlds in their habitable zones and the prospect of future analysis of their atmospheres, but also because they are so plentiful. Comprising perhaps 80 percent of all stars, they may well […]

Heliophysics with Interstellar Implications

Aug 19, 2019


You would think that heading toward the Sun, rather than away from it, would not necessarily fall under Centauri Dreams’ purview, but missions like the Parker Solar Probe have reminded us that extreme environments are ideal testing grounds for future missions. Build a heat shield that can take you to within 10 solar radii of […]

Looking for Life Under Flaring Skies

Aug 16, 2019


The faint glow of a directly imaged planet will one day have much to tell us, once we’ve acquired equipment like the next generation of extremely large telescopes (ELTs), with their apertures measuring in the tens of meters. Discovering the makeup of planetary atmospheres is an obvious deep dive for biosignatures, but there is another. […]

Modeling Early JWST Work on TRAPPIST-1

Aug 15, 2019


So much rides on the successful launch and deployment of the James Webb Space Telescope that I never want to take its capabilities for granted. But assuming that we do see JWST safely orbiting the L2 Lagrange point, the massive instrument will stay in alignment with Earth as it moves around the Sun. allowing its […]

Nautilus: New Lens Concept for Space-based Array

Aug 14, 2019


As we’ve been talking about the limitations of giant telescopes in recent days — and a possible solution in David Kipping’s idea of a ‘terrascope’ — it pays to keep in mind how our ability to collect light has changed over the years. Thus the figure below, which is drawn from a new paper from […]

The Terrascope: Challenges Going Forward

Aug 13, 2019


Yesterday I renewed our acquaintance with the idea that large natural objects can stand in for technologies we have previously been engineering into existence. The progression is a natural one. The early telescope work of Hans Lippershey and Galileo Galilei began with small instruments, but both refractor and later reflector designs would grow to enormous […]

Planetary Lensing: Enter the ‘Terrascope’

Aug 12, 2019


I’m always fascinated with ideas that do not disrupt the known laws of physics but imply an engineering so vast that it seems to defy practical deployment. Centauri Dreams readers are well aware by now of some of Robert Forward’s vast mental constructions, including lightsails in the hundreds of kilometers and enormous lenses in the […]

Summer Break

Jul 29, 2019


And boy do I need it! See you in two weeks.

TESS: Concluding First Year of Observations

Jul 26, 2019


If it seemed amazing to me that 50 years had gone by since Apollo 11, it surprises me as well to realize that, on a much shorter scale, the Transiting Exoplanet Survey Satellite (TESS) has been at work for a full year. In a recent news release, NASA is calling this “the most comprehensive planet-hunting […]

VERITAS: Strengthening the Optical SETI Search

Jul 25, 2019


Breakthrough Listen has just announced a new optical SETI effort in partnership with the VERITAS Collaboration. The news took me by surprise, for VERITAS (Very Energetic Radiation Imaging Telescope Array System) generally deals in high-energy astrophysics, with a focus on gamma rays, which signal their presence through flashes of Cherenkov radiation when they strike the […]

Sail Deployment: Reflections on LightSail 2

Jul 24, 2019


One thing that James E. Webb insisted on during his tenure as NASA administrator was that the space program was larger than an attempt to get humans to the Moon. The man who did so much to ensure that Apollo would succeed, and who will be rightfully honored in the form of the James Webb […]

Remembering Chris Kraft

Jul 23, 2019


As a poignant and unexpected coda to the celebrations of the Apollo 11 anniversary we learn of the death of Chris Kraft, the man who created NASA’s Mission Control from scratch in the early days of the manned space program and was head of Flight Operations during that critical period. Death came at age 95 […]

From the Moon to the Stars

Jul 22, 2019


I’ll close my coverage of the Apollo 11 anniversary with thoughts from Marc Millis. I was startled to discover, fifty years after watching the first landing on the Moon, that the anniversary seemed almost elegiac. So many expectations that have yet to emerge, so much energy still waiting to find an Apollo-like focus. Marc has […]

Neil Armstrong: 2011 Speech in Australia

Jul 19, 2019


If a connection between accounting and astronautics seems tenuous, it’s one that Neil Armstrong invoked on the 24th of August, 2011, when he spoke before CPA Australia in Sydney, doubtless motivated by his father’s career as an auditor. Armstrong stopped signing autographs in 1996 and rarely spoke in public, but accepted the Sydney invitation, according […]

Lunar Landing Backup: Apollo’s Abort Guidance System

Jul 18, 2019


Al Jackson shares more memories of Apollo this morning in his account of a little known spacecraft component, the Abort Guidance System. A NASA historical document on computers aboard the Apollo spacecraft refers to the Abort Guidance System as “…probably the most obscure computing machine in the manned spaceflight program to date.” The AGS was […]

How Americans See Space Exploration

Jul 17, 2019


These are unusual times for a site that usually begins its investigations no closer than the outer Solar System (asteroids are an exception). But there is no way to ignore the Apollo 11 anniversary, nor would I even consider it. Tomorrow I’ll have further reminiscences from Al Jackson, who was on the scene in Houston […]

On Apollo, Hayabusa2 & Persistence

Jul 16, 2019


Remembering how I felt 50 years ago when Apollo 11 launched, I fully understand those whose sense of let-down at the abrupt end of the moon landings has never gone away. And yes, I was one of those who assumed we would be on Mars by 1990 or earlier, with missions to the Jovian moons […]

Sorting Out Circumplanetary Disks

Jul 15, 2019


Some confusion has arisen about a possible circumplanetary disk in the system PDS 70, which I wrote about recently (see Exoplanet Moons in Formation?, from June 7). A team led by led by Valentin Christiaens at Monash (Australia) presented evidence for the kind of disk that may have formed the moons of Jupiter around the […]

Extending the Astrobiological ‘Red Edge’

Jul 12, 2019


A useful exercise for learning how to look for life elsewhere is to try to find it right here on Earth. Thus Carl Sagan’s observations of our planet via data taken during the 1993 flyby of the Galileo spacecraft, which was doing a gravity assist maneuver enroute to Jupiter. Sagan and team found pigments on […]

A Gravitational Wave Approach to Exoplanets

Jul 11, 2019


We should always be on the lookout for new ways of finding exoplanets. Right now we’re limited by our methods to stars within the neighborhood of the Sun (in galactic terms), for both radial velocity and transit detections are possible only around brighter, closer stars. The exception here is gravitational microlensing, capable of probing deep […]

Keeping Voyager Alive

Jul 10, 2019


One of the many legacies of the Voyager spacecraft is the Interstellar Mapping and Acceleration Probe (IMAP). Scheduled for a 2024 launch, IMAP has as part of its charter the investigation of the solar wind’s interactions with the heliosphere, drawing on data from an area into which only the Voyagers have thus far ventured. Let […]

Unusual Atmosphere of a ‘Sub-Neptune’

Jul 9, 2019


We refine our terminology as we go when a field as new as exoplanetology is in play. Take the case of GJ 3470b. At 12.6 Earth masses, is this a ‘sub-Neptune’ or a ‘super Earth’? Neptune itself is 17 Earth masses, so I’d on balance give the nod to ‘sub-Neptune,’ though categories here get confusing. […]

Apollo’s Lunar Module Simulator

Jul 8, 2019


I’m staying in Apollo mode this morning because after Friday’s piece about the Lunar Module Simulator, Al Jackson forwarded two further anecdotes about his work on it that mesh with the discussion. Al also reports that those interested in learning more about the LMS can go to the official Lunar Module familiarization manual, which is […]

Reminiscences of Apollo

Jul 5, 2019


While compiling materials for a book on Apollo 11, Neil McAleer accumulated a number of historical items that he passed along to me (thanks, Neil!), and I’m thinking that with the 50th anniversary of the first landing on the Moon approaching, now is the right time to publish several of these. Centauri Dreams has always […]

Life from a Passing Star

Jul 3, 2019


Remember ‘Nemesis’? The idea was that mass extinctions on Earth recur on a timescale of between 20 and 40 million years, and that this recurrence could be accounted for by the existence of a faint star in a highly elliptical orbit of the Sun. Put this object on a 26 million year orbit and it […]

Study Sees ‘Oumuamua as a Natural Object

Jul 2, 2019


A paper called “The Natural History of ‘Oumuamua,” just out in Nature Astronomy, puts the emphasis on the word ‘natural.’ We know how much of a stir in the media the interstellar visitor has made given its peculiarities, and the hypothesis put forward by Harvard’s Avi Loeb that it could be a technological object. Now […]

Benchmarks for a ‘Second Venus’

Jul 1, 2019


The latest find from TESS, the Transiting Exoplanet Survey Satellite, is a reminder of how interesting, and useful, a planetary system can be even if we find no Earth-like worlds there. This seems obvious, but so much of the public attention to exoplanets has to do with finding a clone of our own world that […]

‘Dragonfly’ Chosen to Explore Titan

Jun 28, 2019


We’ve looked at a number of concepts for exploring Titan over the years, from aircraft capable of staying aloft for a year or more to balloons and boats that would float on the moon’s seas. Dragonfly, the work of a team based at Johns Hopkins University’s Applied Physics Laboratory in Laurel, MD, is a rotorcraft […]

Progress on Asteroid Discovery, Impact Mitigation

Jun 27, 2019


We have two stories with good news on the asteroid impact front this morning. The first, out of the University of Hawaii’s Institute for Astronomy, is the announcement of the detection of a small asteroid prior to its entering the Earth’s atmosphere. That many not sound unusual, but this is the first time an object […]

Inside ESA’s Advanced Concept Team Interstellar Workshop

Jun 26, 2019


It’s always good to have eyes and ears on the ground at events I can’t get to, so I was pleased when Aleksandar Shulevski contacted me with the offer to send back notes from the European Space Agency’s Advanced Concepts Team Interstellar Workshop in Noordwijk in the Netherlands. Born and raised in Bitola, Republic of […]

Titan and Astrobiology

Jun 25, 2019


Night launches are spectacular, that’s for sure, especially with a rocket as muscular as the SpaceX Falcon Heavy. Less spectacular, at least at this point in my life, is staying up until 0230, but delays are part of the rocket business, and what counts is a launch successful in everything but the return of the […]

Into the Uranian Rings

Jun 24, 2019


Both DSAC (the Deep Space Atomic Clock) and LightSail 2 are on the line when a SpaceX Falcon Heavy launches on Monday evening. Both missions portend interesting developments in our push to deep space, with DSAC testing our ability to extend navigational autonomy, and LightSail 2 a solar sail that will use the power of […]

Ring Imagery from Cassini’s Deep Dive

Jun 21, 2019


Cassini’s productivity at Saturn continues to provide fodder for scientific papers and encouragement for the builders of complex missions, who have seen enough data gathered by this one to guarantee continuing insights into the ringed planet for years to come. The June 14 issue of Science offers up four papers (citations below) that show results […]

Can We Catch the Next ‘Oumuamua?

Jun 20, 2019


Ever since the passage of interstellar interloper ‘Oumuamua, we’ve become aware of the opportunities presented by objects entering our system from interstellar space, at the same time wishing we had the resources at hand to investigate them close-up. Andreas Hein and colleagues at the Initiative for Interstellar Studies have examined the possibilities for reaching ‘Oumuamua […]

Breakthrough Listen: SETI Data Release

Jun 19, 2019


On Monday I was talking about the rise of open access scientific journals, using the European Space Agency’s Acta Futura as just one example. The phenomenal arXiv service, not itself a journal but a repository for preprints of upcoming papers, is already well known in these pages. Now we have the largest public release of […]

CARMENES: Two Habitable Zone Planets around a Nearby Red Dwarf

Jun 18, 2019


We rarely talk about Teegarden’s Star when mentioning interesting objects near the Solar System, probably because the star was only discovered in 2003 and until now had not been known to host planets. Today we learn, however, that an international team led by the University of Göttingen has found two planets close to Earth mass […]

ESA Advanced Concepts Team Interstellar Workshop

Jun 17, 2019


Given the difficulties that persist in retrieving many good papers from behind publisher firewalls, I’m always glad to see open access journals plying their trade. Let me call your attention in particular to Acta Futura, which comes out of the scientists working with the European Space Agency’s Advanced Concepts Team. Acta Future defines itself as […]

Giant Planets Less Likely around Sun-like Stars

Jun 14, 2019


We’re getting first results from the Gemini Planet Imager Exoplanet Survey (GPIES), a four-year look at 531 young, nearby stars that relies on the instrument’s capabilities at direct imaging. Data from the first 300 stars have been published in The Astronomical Journal, representing the most sensitive, and certainly the largest direct imaging survey for giant […]

What Sodium Chloride Means for Europa’s Ocean

Jun 13, 2019


We have priceless data on Europa from the Voyager and Galileo missions, but we’re updating earlier interpretations thanks to new work with both the Hubble Space Telescope and the Keck Observatory on Mauna Kea (Hawaii). Thus the discovery that the yellow color visible on parts of Europa’s surface in visible light is most likely sodium […]

Progress on Starshade Alignment, Stability

Jun 12, 2019


We’re on the cusp of exciting developments in exoplanet detection, as yesterday’s post about the Near Earths in the AlphaCen Region (NEAR) effort makes clear. Adapting and extending the VISIR instrument at the European Southern Observatory’s Very Large Telescope in Chile, NEAR has seen first light and wrapped up its first observing run of Centauri […]

First Light for NEAR: Searching for Planets around Centauri A and B

Jun 11, 2019


I marvel that so many of the big questions that have preoccupied me during my life are starting to yield answers. Getting New Horizons to Pluto was certainly part of that process, as a mysterious world began to reveal its secrets. But we’re also moving on the Alpha Centauri question. We have a habitable zone […]

LightSail 2 Inspires Thoughts on Fictional Sails

Jun 10, 2019


Solar sails are a case of science fiction anticipating the scientific journals, though in an odd way. Engineer Carl Wiley (writing as Russell Saunders) described the physics of solar sailing and some early engineering concepts in the pages of John Campbell’s Astounding back in 1951, but he did it in a nonfiction article of the […]

Exoplanet Moons in Formation?

Jun 7, 2019


We’ve been looking at circumstellar disks for quite some time, and teasing out images of actual planets within them, as witness HR 8799, where four exoplanets have been found. Just recently we saw imagery of a second world around PDS 70, both planets seen by direct imaging as they plowed through the disk of dust […]

1999 KW4: Close-Up of a Double Asteroid

Jun 6, 2019


I’ve argued in these pages that the interstellar effort will be driven as much by planetary protection as by the human exploratory impulse. I count the latter as crucial, but we often think of planetary protection as an immediate response to a specific problem. Let’s place it, though, in context. Now that we’re actively cataloging […]

An Atomic Clock for Deep Space

Jun 5, 2019


NASA’s Orbital Test Bed satellite is scheduled for launch via a SpaceX Falcon Heavy on June 22, with live streaming here. Although two dozen satellites from various institutions will be aboard the launch vehicle, the NASA OTB satellite itself houses multiple payloads on a single platform, including a modular solar array and a programmable satellite […]

A Supernova Link to Ancient Wildfires?

Jun 4, 2019


Did huge fires several million years ago force a transition from forest to savanna in northeast Africa? It’s a tantalizing thought, as such fires have been seen as a possible factor in driving the emergence of bipedalism in our remote ancestors. Adrian Melott (University of Kansas), who looks at the question in a new paper […]

Explaining Luna’s Farside

Jun 3, 2019


The Moon’s farside used to be a convenient setting for wondrous things. After all, no one had ever seen it, setting the imagination free to insert everything from paradisaical getaways (think Shangri-La in space) to secret technologies or alien civilizations. The Soviet Luna 3 image of 1959 took the bloom off that particular rose, but […]

HD 163296: Emerging Insights into Circumstellar Disks

May 31, 2019


We should be glad to run into the unexpected when doing research, because things we hadn’t foreseen often point to new understanding. That’s certainly the case with infant planetary systems as observed through the circumstellar disks of gas and dust surrounding young stars. ALMA (the Atacama Large Millimeter/submillimeter Array) has been central to the study […]

Into the Neptunian Desert

May 30, 2019


A planet labeled NGTS-4b has turned up in a data space where astronomers had not expected it, the so-called ‘Neptunian desert.’ Three times Earth radius and about 20 percent smaller than Neptune, the world was discovered with data from the Next-Generation Transit Survey (NGTS), which specializes in transiting worlds around bright stars, by researchers from […]

Triton: Insights into an Icy Surface

May 29, 2019


Al Jackson reminds me in a morning email that today is the 100th anniversary of the Arthur Eddington expedition that demonstrated the validity of Einstein’s General Relativity. The bending of starlight could be observed by looking at the apparent position of stars in the vicinity of the Sun during a solar eclipse. Eddington’s team made […]

A Comet Family with Implications for Earth’s Water

May 28, 2019


‘Hyperactive’ comets tend to call attention to themselves. Take Comet Hartley 2 (103P/Hartley), which was visited by the EPOXI mission (formerly Deep Impact) in November of 2010. Three months of imaging and 117,000 images and spectra showed us just how much water and carbon dioxide the little comet was producing in the form of asymmetrical […]

Dataset Mining Reveals New Planets

May 24, 2019


I’m always interested in hearing about new ways to mine our abundant datasets. Who knows how many planets may yet turn up in the original Kepler and K2 data, once we’ve applied different algorithms crafted to tease out their evanescent signatures. On the broader front, who knows how long we’ll be making new discoveries with […]

Is High Definition Astrometry Ready to Fly?

May 23, 2019


In a white paper submitted to the Decadal Survey on Astronomy and Astrophysics (Astro2020), Philip Horzempa (LeMoyne College) suggests using technology originally developed for the NASA Space Interferometry Mission (SIM), along with subsequent advances, in a mission designed to exploit astrometry as an exoplanet detection mode. I’m homing in on astrometry itself in this post […]

Insulating a Plutonian Ocean

May 22, 2019


An ocean inside Pluto would have implications for many frozen moons and dwarf planets, not to mention exoplanets where conditions at the surface are, like Pluto, inimical to life as we know it. But while a Plutonian ocean has received considerable study (see, for example, Francis Nimmo’s work as discussed in Pluto: Sputnik Planitia Gives […]

New Horizons: Results and Interpretations

May 21, 2019


Another reminder that the days of the lone scientist making breakthroughs in his or her solitary lab are today counterbalanced by the vast team effort required for many experiments to continue. Thus the armies involved in gravitational wave astronomy, and the demands for big money and large populations of researchers at our particle accelerators. So, […]

A Neutrino Beam Beacon

May 17, 2019


If you want to look for possible artifacts of advanced civilizations, as do those practicing what is now being called Dysonian SETI, then it pays to listen to the father of the field. My friend Al Jackson has done so and offers a Dyson quote to lead off his new paper: “So the first rule […]

Survivors: White Dwarf Planets

May 16, 2019


The term ‘destruction radius’ around a star sounds like something out of a generic science fiction movie, probably one with lots of laser battles and starship crews dressed in capes. It’s a descriptive phrase as used in this University of Warwick (UK) news release, but let’s go with ‘Roche radius’ instead. Dimitri Veras, a physicist […]

Toward a High-Velocity Astronomy

May 15, 2019


Couple the beam from a 100 gigawatt laser with a single-layer lightsail and remarkable things can happen. As envisioned by scientists working with Breakthrough Starshot, a highly reflective sail made incredibly thin — perhaps formed out of graphene and no thicker than a single molecule — could attain speeds of 20 percent of c. That’s […]

Breakthrough Starshot: Early Testing of ‘Wafer-craft’ Design

May 14, 2019


Recent tests of a ‘wafer-craft’, an early prototype for what may one day be the ‘starchip’ envisioned by scientists involved with the Breakthrough Starshot project, have been successful. The work grows out of a NASA-funded effort led by Philip Lubin (UC Santa Barbara), whose investigations into large scale directed energy systems began in 2009. Lubin […]

Europa’s Oxygen and Aerobic Life

May 10, 2019


Few destinations in the Solar System have excited the imagination as much as Europa. Could a deep ocean beneath the ice support a biosphere utterly unlike our own? If so, we could be looking at a second emergence of life unrelated to anything on Earth, with implications for the likelihood of life throughout the cosmos. […]

Haumea: Probing an Outer System Ring

May 9, 2019


I rarely get the chance to talk about the exotic dwarf planet Haumea, but it’s a personal favorite when it comes to the outer Solar System. That’s because of its odd shape (a bit like an American football), evidently the result of a catastrophic collision, which makes it an interesting object for close study if […]

Planetary Interiors a Key to Habitability

May 8, 2019


Interdisciplinary approaches to new data offer a robust way to see past the conventions of a specialized field, noting connections that provide perspective and deepen understanding. That idea is sound across many disciplines, but it is getting new emphasis with an essay in Science asking whether we have not been too blinkered in our approach […]

Evidence for an Early Neutron Star Merger Near the Solar System

May 7, 2019


Massive elements can build up in celestial catastrophes like supernovae, with the rapid-, or r-process, producing neutrons at a high rate as elements much heavier than lead or even uranium emerge. But we’re learning that such events happen not just in supernovae but also in neutron star mergers, which are thought to occur only a […]

“An Intellectual Carrot – The Mind Boggles!” Dissecting The Thing from Another World

May 3, 2019


Centauri Dreams’ resident movie critic turns his attention to a personal favorite from the canon of science fiction films. My own memories of The Thing from Another World go back to late Saturday night black-and-white TV, where I first saw the chilling tale as a boy. The scene where the team fans out on the […]

99942 Apophis: The Value of a Close Approach

May 2, 2019


The approach of the asteroid 99942 Apophis in April of 2029 offers an opportunity to study a sizeable asteroid through both radar and optical telescopes. Marina Brozović, a radar scientist at the Jet Propulsion Laboratory, points out that radar studies of the object might resolve surface details that are no more than a few meters […]

Corridor of Ice Identified on Titan

May 1, 2019


What an interesting thing Titan’s atmosphere turns out to be. A fine haze produced by sunlight breaking apart methane molecules settles continuously to the surface, leaving organic liquid and solid sediments. Titan also has large lakes, but these contain about a third of the necessary methane, available through evaporation, to replenish that atmosphere, which should […]

Refined Parameters for an Expanding Universe

Apr 30, 2019


When it comes to matching what we know of the early universe, as seen in the Cosmic Microwave Background (CMB), with what we see today, astronomers have their work cut out for them. Edwin Hubble could demonstrate that the universe was expanding by studying the redshift of galaxies as they receded, but the rate of […]

Probing Parenago: A Dialogue on Stellar Discontinuity

Apr 26, 2019


The publication of a paper called “New Features of Parenago’s Discontinuity from Gaia DR1 Data” by V. V. Vityazev and colleagues brought us a new look at an unusual observation. Parenago’s Discontinuity refers to the fact that red, cooler stars move faster in the direction of galactic rotation than blue, hotter stars, based on Hipparcos […]

An Earth-sized Planet for TESS

Apr 25, 2019


If Kepler’s task was to give us a first statistical cut at the distribution of exoplanets in the galaxy, TESS (Transiting Exoplanet Survey Satellite) has a significantly different brief, to use its four cameras to study stars that are near and bright. Among these we may hope to find the first small, rocky planets close […]

New Planet Detected in Circumbinary System

Apr 24, 2019


The transit method has proven invaluable for exoplanet detection, as the runaway success of the Kepler/K2 mission demonstrates. But stars where planets have been detected with this method are still capable of revealing further secrets. Consider Kepler-47. Here we have a circumbinary system some 3340 light years away in the direction of the constellation Cygnus, […]

Huge White Light Flare on a Tiny Star

Apr 23, 2019


About 250 light years away there is a faint object that is on the borderline between brown dwarf and star. Only a tenth of the radius of our Sun, ULAS J224940.13-011236.9 was actually too faint for most telescopes to observe until a huge flare lit it up, turning this L dwarf, among the lowest mass […]

Chinese Mission to an Earth Co-Orbital

Apr 22, 2019


This morning’s entry resonates with Jim Benford’s recent work on objects that are co-orbital with Earth (see A SETI Search of Earth’s Co-Orbitals). You’ll recall that Benford argues for close study of co-orbitals like Cruithne (3753), a 5-kilometer object with closest approach to Earth of 0.080 AU, and 2010 TK7, which oscillates around the Sun-Earth […]

TRAPPIST-1: Of Flux and Tides

Apr 18, 2019


Seven planets of roughly Earth-size make TRAPPIST-1 a continuing speculative delight, as witness the colorful art it generates below. And with three of the planets arguably in the star’s habitable zone, this diminutive star attracts the attention of astrobiologists anxious to examine the possible parameters under which they orbit. One thing that is only now […]

Detection of an Interstellar Meteor

Apr 17, 2019


Do we have a second interstellar visitor, following on the heels of the controversial ‘Oumuamua? If so, the new object is of a much different nature, as was its detection. In 2014, a meteor north of Manus Island, off the coast of Papua New Guinea produced a powerful blast that, upon analysis, implied a ∼ […]

Going Interstellar in Europe

Apr 16, 2019


Foundations of Interstellar Studies Workshop in UK A workshop on interstellar flight titled Foundations of Interstellar Studies is to take place from 27 to 30 June of this year in the town of Charfield, Gloucestershire, United Kingdom, at the current headquarters of the Initiative for Interstellar Studies. This follows an initial ‘foundations’ conference in 2017 […]

Proxima Centauri c?

Apr 15, 2019


A possible second planet around Proxima Centauri raises all kind of questions. I wasn’t able to make it to Breakthrough Discuss this year, but I’ve gone over the presentation made by Mario Damasso of Turin Observatory and Fabio Del Sordo of the University of Crete, recounting their excellent radial velocity analysis of the star. Proxima […]

Reflections on Messier 87’s Black Hole

Apr 11, 2019


Messier 87, a massive elliptical galaxy in the Virgo cluster, is some 55 million light years from Earth, and even though the black hole at its center has a mass 6.5 billion times that of the Sun, it’s a relatively small object, about the size of our Solar System. Resolving an image of that black […]

M-Dwarfs: Weighing UV Radiation and Habitability

Apr 10, 2019


With 250 times more X-ray radiation than Earth receives and high levels of ultraviolet, would Proxima b, that tantalizing, Earth-sized world around the nearest star, have any chance for habitability? The answer, according to Jack O’Malley-James and Lisa Kaltenegger (Cornell University) is yes, and in fact, the duo argue that life under these conditions could […]

A Major Hubble Survey of the Kuiper Belt

Apr 9, 2019


You’ll recall that well before New Horizons completed its primary mission at Pluto/Charon, the search was on for a Kuiper Belt Object that could serve as its next destination. Eventually we found Ultima Thule (2014 MU-69), from which priceless data were gathered at the beginning of January. Finding the target wasn’t easy given the distances […]

Hayabusa2 Impactor Deployment

Apr 8, 2019


Putting a crater on an asteroid is no small matter, for it allows us to gather samples to further nail down the object’s composition. The Japan Aerospace Exploration Agency (JAXA) has achieved the feat on asteroid Ryugu using the Small Carry-on Impactor (SCI) carried by the Hayabusa2 spacecraft. Confirmation of the crater and details about […]

White Dwarf Debris Suggests a Common Destiny

Apr 5, 2019


An iron and nickel-rich planetesimal is apparently all that survives of a planet following the death of its star, SDSS J122859.93+104032.9. We are talking about an object in an orbit around a white dwarf so tight that it completes a revolution every two hours. Significantly, spectroscopic methods were used to make the identification, the first […]

HR 8799e: A New Level of Exoplanet Imaging

Apr 4, 2019


A method for enhanced exoplanet investigation takes center stage today as we look at the GRAVITY instrument, a near-infrared tool aided by adaptive optics that brings new precision to exoplanet imaging. In operation at the European Southern Observatory’s Very Large Telescope Interferometer (VLTI) at Paranal Observatory in Chile, GRAVITY works with the combined light of […]

Shaping the TESS Target List

Apr 3, 2019


Picking up on TESS (Transiting Exoplanet Survey Satellite), one of whose discoveries we examined yesterday, comes news of a document called the “TESS Habitable Zone Star Catalog.” The work of Cornell astronomers in collaboration with colleagues at Lehigh and Vanderbilt, the paper has just been published in Astrophysical Journal Letters (citation below), where we find […]

TESS: A ‘Hot Saturn’ & Asteroseismology

Apr 2, 2019


It’s good to see TESS, the Transiting Exoplanet Survey Satellite, producing early results. We’re coming up on the one year anniversary of its launch last April 18, with the spacecraft’s four cameras doing month-long stares at 26 vertical strips of sky, beginning with the southern hemisphere. Two years of such scanning will produce coverage of […]

A Slow Motion Asteroid Breakup

Apr 1, 2019


The odd lightcurve of the star known as VVV-WIT-07, discussed here last Friday, reminds us that even as we start seeing such signatures, we are tuning up our ability to find others. It’s a point that bears repeating from the paper on this work: …surveys like ours, apart of course from its irregular cadence, may […]

Unusual Lightcurve of a ‘What Is This’ Star

Mar 28, 2019


VISTA (Visible and Infrared Survey Telescope for Astronomy) is a near-infrared instrument located at the European Southern Observatory’s Paranal site, and is by all accounts the world’s largest survey telescope, with extremely wide field of view and sensitive detectors. On the peak next to ESO’s Very Large Telescope (VLT), VISTA shares its exceptional viewing conditions […]

The Problem with Probes

Mar 27, 2019


I’ll wrap up this three-part series on ‘lurker’ probes and ways of finding them with Keith Cooper’s provocative take on the matter. A contributor to Centauri Dreams whose far-ranging ideas have fueled a number of dialogues here (see the archives), Keith is editor of Astronomy Now and the author of the upcoming book The Contact […]

Gregory Benford: Further Thoughts on ‘Lurkers’

Mar 26, 2019


Because I’ve been re-reading Gregory Benford’s Galactic Center sequence (now into Furious Gulf), I want to quickly mention the galactic center simulation available here, which offers a 360-degree, ultra-high-definition view based on Chandra X-ray observations as massaged by NASA supercomputers. It’s lively stuff, showing “the effects of dozens of massive stellar giants with fierce winds […]

A SETI Search of Earth’s Co-orbitals

Mar 22, 2019


One objection to SETI is that it is not falsifiable — there is no point at which a lack of signals can prove that extraterrestrial civilizations do not exist. But there are some aspects of SETI that can be falsifiable. Consider a class of objects near enough for us to investigate not only with listening […]

Working with the Unexpected at Asteroid Bennu

Mar 21, 2019


We know by now to expect surprises when we do something for the first time with a spacecraft. The latest case in point is OSIRIS-REx, which has revealed multiple unexpected facets of the asteroid Bennu, near which it has been operating since December. Consider the surface of the asteroid, a key factor in how the […]

Carbon Monoxide as Biosignature?

Mar 20, 2019


Biosignature gases are those that can alert us to the possibility of life on a planet around another star. We’re moving into the era of biosignature observation by studying the atmospheres of such planets through instruments like the James Webb Space Telescope, and the effort to catalog the combinations of atmospheric gases that point to […]

Exploring our System’s Dust Lanes

Mar 19, 2019


Dust rings in the Solar System are of interest because they offer clues about the formation of the planets, as well as allowing us to contrast our own circumstellar dust with what we see around other stars in varying stages of planetary development. Recent work out of NASA’s Goddard Space Flight Center offers a dust […]

Spacefaring Mythologies

Mar 15, 2019


I became fascinated with Scandinavian mythologies in grad school and wound up doing a deep dive into early Icelandic literature. Heroic tales from a worldview long superceded proved a rich source of materials, but is myth always a thing of the past? Joseph Campbell would speak about ritual as the only way to participate in […]

Asteroid Bennu: Changes in Rotation Rate

Mar 14, 2019


Tuesday’s post on asteroids and what it would take to deflect or destroy one has been usefully reinforced by a new paper from Mike Nolan (Lunar and Planetary Laboratory, University of Arizona) and colleagues, who discuss their findings in Geophysical Research Letters. Here we’re looking at observations of the near-Earth asteroid (101955) Bennu, both archival […]

A Biosignature Plus for K-Class Stars

Mar 13, 2019


Kepler-62 is a reminder of how interesting K-class stars (like Alpha Centauri B) can be. Here we find two worlds that are conceivably in the habitable zone of their star, with Kepler 62f, imagined in the image below, orbiting the host star every 267 days. Kepler-62e, the bright object depicted to the right of the […]

Asteroids in Collision: A New Model

Mar 12, 2019


If we were to find an asteroid on a trajectory to impact the Earth, what strategies would we use to stop it? Recent work from Johns Hopkins University shows that there is a wide range in our thinking on what happens to asteroids under various mitigation scenarios. Much depends, of course, on the asteroid’s composition, […]

A Sparse Population of Small Kuiper Belt Objects?

Mar 11, 2019


One problem with learning about the Kuiper Belt is that objects out there are small and details from Earth-based imaging all too sparse. New Horizons yielded up a world of wonders with Pluto, showing us nitrogen glaciers, and mountains fully 4 kilometers tall. But even relative proximity doesn’t help us in some areas. Pluto’s surface […]

Confirming Kepler-1658b: Tight Orbit around an Evolved Star

Mar 8, 2019


A planet designated Kepler-1658b is, after a good deal of investigation, demonstrated to be a ‘hot Jupiter,’ orbiting a star that is 50 percent more massive and three times larger than the Sun. The sizzling world is close enough to its star that were you to look into its sky from near the planet, the […]

Black Hole Propulsion as Technosignature

Mar 6, 2019


When he was considering white dwarfs and neutron stars in the context of what he called ‘gravitational machines,’ Freeman Dyson became intrigued by the fate of a neutron star binary. He calculated in his paper of the same name (citation below) that gradual loss of energy through gravitational radiation would bring the two neutron stars […]

Investigating the ‘Halo Drive’

Mar 5, 2019


One of the interesting things about gravitational assists is their ability to accelerate massive objects up to high speeds, provided of course that the astrophysical object being used for the assist is moving at high speeds itself. Freeman Dyson realized, as we saw yesterday, that a pair of tightly rotating white dwarfs could offer such […]

Pondering the ‘Dyson Slingshot’

Mar 4, 2019


Let’s start the week by talking about gravitational assists, where a spacecraft uses a massive body to gain velocity. Voyager at Jupiter is the classic example, because it so richly illustrates the ability to alter course and accelerate without propellant. Michael Minovitch was working on this kind of maneuver at UCLA as far back as […]

Evidence of Passing Stars

Mar 1, 2019


The sheer range of possible outcomes in a planetary system is something we’re beginning to appreciate with each new exoplanet. Not long ago we looked at a possible collision between two large worlds in the young system Kepler 107, and the knowledge of how violent an evolving system can be informs our thinking about the […]

Tuning Up HPF: The Habitable Zone Planet Finder

Feb 28, 2019


If you had a hot new instrument like the Habitable Zone Planet Finder (HPF) now mounted at the Hobby-Eberly Telescope (McDonald Observatory, University of Texas), how would you run it through its paces for fine-tuning and verification of its performance specs? The team behind HPF has chosen to deploy the instrument during its commissioning phase […]

Alternatives to DNA-Based Life

Feb 27, 2019


The question of whether or not we would recognize extraterrestrial life if we encountered it used to occupy mathematician and historian Jacob Bronowski (1908-1974), who commented on the matter in a memorable episode of his 1973 BBC documentary The Ascent of Man. “Were the chemicals here on Earth at the time when life began unique […]

Ultima Thule at Highest Resolution

Feb 26, 2019


One of the most enjoyable interviews I’ve been involved with lately was with Ryan Ferris, who runs the podcast Cosmic Tortoise from Christchurch, New Zealand. Ryan’s questions were sharp and of a philosophic bent, plumbing issues like the purpose and direction of human exploration. From Thor Heyerdahl’s extraordinary experiments at shipbuilding and navigation to the […]

Hayabusa2: Asteroid Touchdown

Feb 25, 2019


For those of you who’ve been asking, I think the best way to keep up with the Hayabusa2 mission to asteroid Ryugu is via Twitter, @haya2e_jaxa. The news continues to percolate via websites and various publications, with a sustained ripple when the spacecraft successfully tested its sample mechanism and touched down on the asteroid. I’ll […]

A White Dwarf with Puzzling Rings

Feb 22, 2019


Backyard Worlds: Planet 9 is a project worth investigating. Using a database drawn from NASA’s Wide-field Infrared Survey Explorer (WISE), Backyard Worlds: Planet 9 is probing the cosmos at infrared wavelengths. Volunteers search the WISE data in a ‘citizen science’ effort that has already discovered more than 1,000 likely brown dwarfs. Now we have news […]

Finding Neptune’s Smallest Moon

Feb 21, 2019


What a lively place Neptune used to be, at least back in the days when the planet captured Triton, doubtless a Kuiper Belt Object now in a retrograde orbit around the primary. Recent work led by Mark Showalter (SETI Institute) puts the Hubble Space Telescope to work in studying one result of the sudden acquisition […]

Kepler 107: Collision of Worlds

Feb 20, 2019


It seems increasingly clear that the factors that govern what kind of a planet emerges where in a given stellar system are numerous and not always well understood. Beyond the snowline, planets draw themselves together from the ice and other volatiles available in these cold regions, so that we wind up with low-density gas or […]

Gravitational Wave Astronomy: Enter the ‘Standard Siren’

Feb 19, 2019


Recently we’ve talked about ‘standard candles,’ these being understood as objects in the sky about which we know the total luminosity because of some innate characteristic. Thus the Type 1a supernova, produced in a binary star system as material from a red giant falls onto a white dwarf, causing the smaller star to reach a […]

Breakthrough Propulsion Study

Feb 15, 2019


Ideas on interstellar propulsion are legion, from fusion drives to antimatter engines, beamed lightsails and deep space ramjets, not to mention Orion-class fusion-bomb devices. We’re starting to experiment with sails, though beaming energy to a space sail is still an unrealized, though near-term, project. But given the sheer range of concepts out there and the […]

Planet Formation: How Ocean Worlds Happen

Feb 14, 2019


It’s hard to fathom when we look at a globe, but our planet Earth’s substantial covering of ocean is relatively modest. Alternative scenarios involving ‘water worlds’ include rocky planets whose silicate mantle is covered in a deep, global ocean, with no land in sight. Kilometer after kilometer of water covers a layer of ice on […]

Looking Back from System’s Edge

Feb 13, 2019


Sometimes the way we discover new things is by looking back, as witness the blue haze of Pluto. The image below comes, of course, from New Horizons, taken after the flyby and looking back in the direction of the Sun. Here we’re looking at a mosaic combining black and white LORRI images (Long Range Reconnaissance […]

2019 Symposium Call for Papers

Feb 12, 2019


6th Interstellar Symposium and Interstellar Propulsion Workshop – TVIW 2019 In collaboration with the National Aeronautics and Space Administration (NASA), the Tennessee Valley Interstellar Workshop (TVIW) hereby invites participation in its 6th Interstellar Symposium and Interstellar Propulsion Workshop -hosted by Wichita State University (WSU) and Ad Astra Kansas Foundation – to be held from Sunday, […]

SETI’s Charismatic Megafauna

Feb 8, 2019


The search for technosignatures that could flag the presence of extraterrestrial cultures has accelerated in recent times with projects like Glimpsing Heat from Alien Technologies at Penn State and numerous papers. Or is the better term not ‘cultures’ but ‘societies,’ or ‘civilizations’? SETI’s funding challenges, at least from government agencies, point to the need for […]

Perspectives Beyond the Moon

Feb 7, 2019


Today we re-enter the realm of perspective-altering photographs, images that open new vistas in our early reconnaissance of the Solar System. Before October 7, 1959, we had little knowledge of the far side of the Moon, even though librations allowed the occasional glimpse at extremely low angles of a small part of it. The Soviet […]

Refining the Shape of the Milky Way

Feb 6, 2019


Figuring out the shape of things — where to place what we see in the sky in a 3-D representation — has always been challenging. We’re looking out at a disk of stars from well within it, and it wasn’t until the 1920s and the work of Edwin Hubble that we began to see there […]

Cassini Data on Saturn’s Rings, Clouds

Feb 5, 2019


Larry Klaes’ article on the film Silent Running, with its images of Saturn originally intended for 2001: A Space Odyssey, makes today’s story the obvious segue, and thus gives me the chance to catch up with some work I‘ve been wanting to write about. For scientists using Cassini data have been able to zero in […]

In Wildness is the Preservation of the World: ‘Silent Running’ and Our Choice of Futures

Feb 1, 2019


Centauri Dreams’ resident film critic Larry Klaes continues his in-depth look at science fiction movies with 1972’s Silent Running, whose protagonist is faced with a stark choice far from home. The film rode the era’s surging interest in environmentalism, and while overshadowed in the memory of many of us by 1968’s 2001: A Space Odyssey […]

AI Colonization: The Founder and the Ambassador

Jan 31, 2019


As we look toward future space missions using advanced artificial intelligence, when can we expect to have probes with cognitive capabilities similar to humans? Andreas Hein and Stephen Baxter consider the issue in their paper “Artificial Intelligence for Interstellar Travel” (citation below), working out mass estimates for the spacecraft and its subsystems and applying assumptions […]

Future AI: The Explorer and the Philosopher

Jan 29, 2019


Robert Bradbury had interesting thoughts about how humans would one day travel to the stars, although whether we could at this point call them human remains a moot point. Bradbury, who died in 2011 at the age of 54, reacted at one point to an article I wrote about Ben Finney and Eric Jones’ book […]

Artificial Intelligence and the Starship

Jan 28, 2019


The imperative of developing artificial intelligence (AI) could not be more clear when it comes to exploring space beyond the Solar System. Even today, when working with unmanned probes like New Horizons and the Voyagers that preceded it, we are dealing with long communication times, making probes that can adapt to situations without assistance from […]

The Next Steps in Space

Jan 25, 2019


Most of my research for Centauri Dreams involves looking at papers and presentations on matters involving deep space, whether propulsion systems, closed loop life support, or even possible destinations. That’s why it’s a huge help to get an article like the one below, giving us an overview of current thinking and an analysis of what […]

What’s Next for New Horizons?

Jan 23, 2019


The exuberance of images like the one below captures the drama of Solar System exploration. Scenes like this are emblematic of the early reconnaissance of the Solar System. We saw similar enthusiasm with missions near and far — I’m thinking back, for example, not just to Voyager, but the Viking landings on Mars, and I’m […]

‘Oumuamua, SETI and the Media

Jan 21, 2019


One of the more important things about the interstellar object called ‘Oumuamua is the nature of the debate it has engendered. Harvard astronomer Avi Loeb’s paper examining it as a possible technology has provoked comment throughout the scientific community, as witness Jason Wright’s essay below. Dr. Wright (Penn State) heads the Glimpsing Heat from Alien […]

A Disk at an Angle (and a Remarkable View)

Jan 18, 2019


One of the joys of science fiction is imagining landscapes. What would it be like to stand on Titan, for example, a question that was inescapably influenced in my youth by Chesley Bonestell’s wonderful depictions, as well as novels like Larry Niven’s World of Ptavvs (1966) or Michael Swanwick’s novelette “Slow Life” (Analog, December 2002). […]

A Closer Look at Barnard’s Star b

Jan 17, 2019


Barnard’s Star b, the planet announced last November around the second nearest star system to the Earth, has been the subject of intensive study by an international team led by Ignasi Ribas at the Institute of Space Studies of Catalonia (IEEC), and Institute of Space Sciences (ICE, CSIC). As announced at the recent meeting of […]

Red Dwarf Planets May Lack Needed Volatiles

Jan 16, 2019


We can identify a number of circumstellar disks, but most are too far away to provide internal detail, much less the kind of activity that seems to be showing up around the red dwarf AU Microscopii. For at 32 light years out in the southern constellation Microscopium, AU Microscopii is presenting us with an unusual […]

‘Oumuamua: Future Study of Interstellar Objects

Jan 15, 2019


‘Oumuamua continues to inspire questions and provoke media attention, not only because of its unusual characteristics, but because of the discussion that has emerged on whether it may be a derelict (or active) technology. Harvard’s Avi Loeb examined the interstellar object in these terms in a paper with Shmuel Bialy, one we talked about at […]

Is Most Life in the Universe Lithophilic?

Jan 11, 2019


Seeking life on other worlds necessarily makes us examine our assumptions about the detectability of living things in extreme environments. We’re learning that our own planet supports life in regions we once would have ruled out for survival, and as we examine such extremophiles, it makes sense to wonder how similar organisms might have emerged […]

Technosearch: An Interactive Tool for SETI

Jan 10, 2019


Jill Tarter, an all but iconic figure in SETI, has just launched Technosearch, an Internet tool that includes all published SETI searches from 1960 to the present. A co-founder of the SETI Institute well known for her own research as well as her advocacy on behalf of the field, Tarter presents scientists with a way […]

Ultrahigh Acceleration Neutral Particle Beamer: Concept, Costs and Realities

Jan 7, 2019


The advantages of neutral particle beam propulsion seem clear: Whereas a laser’s photon beams can exchange momentum with the sail, neutral particle beams transfer energy and are considerably more efficient. In fact, as we saw in the first part of this essay, that efficiency can approach 100 percent. A mission concept emerges, one that reaches […]

Ultrahigh Acceleration Neutral Particle Beam-Driven Sails

Jan 3, 2019


Beamed propulsion has clear advantages when it comes to pushing a payload up to interstellar flight speeds, which is why Breakthrough Starshot is looking at laser strategies. But what about a neutral particle beam in conjunction with a magnetic sail? We’ve discussed the possibilities before (see Interstellar Probe: The 1 KG Mission), where I wrote […]

A Closer Look at Ultima Thule

Jan 2, 2019


“We think we are looking at the most primitive object ever imaged by a spacecraft,” said Jeff Moore (NASA Ames) at today’s Ultima Thule press conference. Moore, New Horizons geology and geophysics lead, went on to describe the process of innumerable particles growing into nodes amidst growing low velocity collision and interaction. We are truly […]

OSIRIS-REx: Orbital Operations at Bennu

Jan 2, 2019


Sometimes one mission crowds out another in the news cycle, which is what has happened recently with OSIRIS-REx. The study of asteroid Bennu, significant in so many ways, continues with the welcome news that OSIRIS-REx is now in orbit, making Bennu the smallest object ever to be orbited by a spacecraft. That milestone was achieved […]

New Horizons Healthy and Full of Data

Jan 1, 2019


We’ve just learned that New Horizons is intact and functional, with a ‘phone home’ message at about 1530 UTC that checked off subsystem by subsystem — all nominal — amidst snatches of applause at the Johns Hopkins Applied Physics Laboratory. The solid state recorders (SSR) are full, with pointers indicating that flyby information is there […]

Ultima Thule Flyby Approaches

Dec 31, 2018


Despite the various governmental breakdowns attendant to the event, the New Horizons flyby of Ultima Thule is happening as scheduled, the laws of physics having their own inevitability. Fortunately, NASA TV and numerous social media outlets are operational despite the partial shutdown, and you’ll want to keep an eye on the schedule of televised events […]

Exoplanet Imaging from Space: EXCEDE & Expectations

Dec 26, 2018


We are entering the greatest era of discovery in human history, an age of exploration that the thousands of Kepler planets, both confirmed and candidate, only hint at. Today Ashley Baldwin looks at what lies ahead, in the form of several space-based observatories, including designs that can find and image Earth-class worlds in the habitable […]