Exoplanetary Science

Speculations on Habitable Zone Waterworlds

April 26, 2017

What to make of Fergus Simpson’s new paper on waterworlds, suggesting that most habitable zone planets are of this type? If such worlds are common, we may find that most planets in the habitable zones of their stars are capable of evolving life, but unlikely to host technological civilizations. An explanation for the so-called ‘Fermi […]

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Further Work on TRAPPIST-1

April 25, 2017

A closely packed planetary system like the one we’ve found at TRAPPIST-1 offers intriguing SETI possibilities. Here a SETI search for directed radio transmissions aimed at the Earth gives way to an attempt to overhear ongoing activity within another stellar system. For it’s hard to conceive of any civilization developing technological skills that would turn […]

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The Value of an Exo-Venus

April 10, 2017

Looking back at science fiction’s treatment of Venus, you can see a complete reversal by the 1960s, at which time we had learned enough about the planet to render earlier depictions invalid, and even quaint. Think back to the inundated surface of Venus in Bradbury’s “Death by Rain” (1950) or Henry Kuttner and C. L. […]

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Atmosphere Detected around Super-Earth GJ 1132b

April 7, 2017

There’s interesting news this morning about planets around M-dwarfs. A team of astronomers led by John Southworth (Keele University, UK) has detected an atmosphere around the transiting super-Earth GJ 1132b. While we’ve examined the atmospheres of gas giants and have detected atmospheres on the super-Earths 55 Cancri e and GJ 3470 b, GJ 1132b is […]

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Giant Planet Clues to a Debris Disk Anomaly

March 17, 2017

A massive young planet on the borderline between gas giant and brown dwarf is telling us a bit more about planet formation in general, and circumstellar disk dynamics in particular. Known as HD 106906b, the world is 11 times the mass of Jupiter and no more than 13 million years old. Its position 650 AU […]

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TRAPPIST-1h: Drawing on K2 Data

March 14, 2017

The data recently made available from Campaign 12 of K2 (the Kepler spacecraft’s two-reaction wheel mission) is already paying off in the form of information about the outermost planet in the TRAPPIST-1 system. Campaign 12 (described in Kepler Data on TRAPPIST-1 Coming Online) began on December 15 of 2016 and ran until March 4 of […]

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HD 219134: A Nearby System with Multiple Transits

March 10, 2017

While we’ve all had our eyes fixed on TRAPPIST-1 (amid the still lingering excitement of the discovery of Proxima Centauri b), news about another stellar neighbor has caused only a faint stir. But what’s happening around HD 219134 (Gliese 892) is noteworthy, and it’s interesting to see that Michaël Gillon (University of Liège – Belgium) […]

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Kepler Data on TRAPPIST-1 Coming Online

March 9, 2017

K2 Campaign 12 is an observational window that comes at the right time. Operating as the K2 mission, the Kepler spacecraft collected data from December 15, 2016 to March 4 of this year on the TRAPPIST-1 system. With seven planets, at least six of them likely to be rocky worlds, TRAPPIST-1 is suddenly high on […]

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Biofluorescence: A Potential Biosignature for M-Dwarf Planets

March 8, 2017

The seven planets circling the star TRAPPIST-1 have been lionized in the media, and understandably so, given that more than one have the potential for habitability. But of course M-dwarfs call up the inevitable problems associated with such tiny stars. Habitable planets must orbit close to the star, with the probability of tidal lock and […]

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‘Dust Traps’ and Planet Formation

March 2, 2017

Are we homing in on a ‘missing link’ in our theories of planet formation? Perhaps so, judging from the work of researchers at Swinburne University of Technology, Lyon University and St. Andrews University. The work does not challenge a central principle in current thinking, that planets form out of disks of gas and dust grains […]

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