January 2015

A Review of the Best Habitable Planet Candidates

January 30, 2015

The fascination with finding habitable planets — and perhaps someday, a planet much like Earth — drives media coverage of each new, tantalizing discovery in this direction. We have a number of candidates for habitability, but as Andrew LePage points out in this fine essay, few of these stand up to detailed examination. We’re learning […]

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A Mini-Neptune Transformation?

January 29, 2015

Not long ago we looked at a paper from Rodrigo Luger and Rory Barnes (University of Washington) making the case that planets now in a red dwarf’s habitable zone may have gone through a tortured history. Because of tidal forces causing surface volcanism and intense stellar activity in young stars, a planet’s supply of surface […]

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Small Planets, Ancient Star

January 28, 2015

Finding planets around stars that are two and a half times older than our own Solar System causes a certain frisson. Our star is four and a half billion years old, evidently old enough to produce beings like us, who wonder about other civilizations in the cosmos. Could there be truly ancient civilizations that grew […]

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Enormous Ring System Hints of Exomoons

January 27, 2015

Might there be gas giant planets somewhere with moons as large as the Earth, or at least Mars? Projects like the Hunt for Exomoons with Kepler (HEK) are on the prowl for exomoons, and the possibility of large moons leads to astrobiological speculation when a gas giant is in its star’s habitable zone. Interestingly, we […]

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Who Will Read the Encyclopedia Galactica?

January 23, 2015

Can a universal library exist, once that contains all possible books? Centauri Dreams regular Nick Nielsen takes that as just the starting point in his latest essay, which tracks through Borges’ memorable thoughts on the matter to Carl Sagan, who brought the idea of an Encyclopedia Galactica to a broad audience. But are the two […]

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Giovanni Vulpetti: Clarifying Magsail Concepts

January 22, 2015

Over the years we’ve looked at magnetic sail (magsail) concepts of various kinds and discussed whether a spacecraft could do such things as ‘riding’ the solar wind to high velocities, or use a stellar wind to brake against as it entered a destination solar system. But just how workable is the magsail? In a 2007 […]

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Drake Equation: The Sustainability Filter

January 21, 2015

There are a lot of things that could prevent our species from expanding off-Earth and gradually spreading into the cosmos. Inertia is one of them. If enough people choose not to look past their own lifetimes as the basis for action, we’re that much less likely to think in terms of projects that will surely […]

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Dawn: New Imagery of Ceres

January 20, 2015

Mark January 26 on your calendar. It’s the day when the Dawn spacecraft will take images of Ceres that should exceed the resolution of the Hubble Space Telescope. We’re moving into that new world discovery phase that is so reminiscent of the Voyager images, which kept re-writing our textbooks on the outer Solar System. 2015 […]

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Making the Case for Deep Space

January 19, 2015

I get few questions that are harder to answer than ‘what happened to the sense of adventure that we once had with Apollo?’ And there are few questions I get more often, usually accompanied by ‘how are we going to do starflight if we don’t even have the will to go back to the Moon?’ […]

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Planets to Be Discovered in the Outer System?

January 16, 2015

Having just looked at the unusual ‘warped’ disk of HD 142527, I’m inclined to be skeptical when people make too many assumptions about where planets can form. Is our Solar System solely a matter of eight planets and a Kuiper Belt full of debris, with a vast cometary cloud encircling the whole? Or might there […]

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