Centauri Dreams

Centauri Dreams

Description

Imagining and Planning Interstellar Exploration

Link: www.centauri-dreams.org

Episodes

CARMENES: Two Habitable Zone Planets around a Nearby Red Dwarf

Jun 18, 2019

Description:

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

Description:

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

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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

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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

Description:

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

Description:

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

Description:

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

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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

Description:

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

Description:

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

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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

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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

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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

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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

Description:

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

Description:

‘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

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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

Description:

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

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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

Description:

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

Description:

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

Description:

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

Description:

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

Description:

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

Description:

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

Description:

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

Description:

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

Description:

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

Description:

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

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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

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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

Description:

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

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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

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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

Description:

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

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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

Description:

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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

Description:

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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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‘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

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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

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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

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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

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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

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“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

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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

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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

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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

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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 […]