September 2008

On Stellar Migrations and Habitability

September 18, 2008

The idea of a galactic habitable zone (GHZ) has a certain inevitability. After all, we talk about habitable zones around stars, so why not galaxies? A stellar habitable zone is usually considered to refer to those areas around the star where liquid water can exist on a planetary surface. Those who believe that confining habitable [...]

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Direct Imaging and Its Exoplanetary Uses

September 17, 2008

As I taper back on my post-surgical medications (see yesterday’s post), a coherent universe is gradually coalescing around me once again. Still, I think I’ll take today relatively easy, looking at just one of the two stories I’ve been pondering during my brief convalescence. The first is intriguing not so much because of what it [...]

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A Brief Delay

September 16, 2008

Several interesting items in the news today but I won’t be able to get to them, try as I might. I’m just coming off surgery yesterday (minor), and although I’m otherwise fine, the pain medication I’m taking makes me so groggy that I hesitate to post. So bear with me until tomorrow, when I should [...]

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Evidence for Planets in Protoplanetary Disks

September 15, 2008

Using a near-infrared spectrograph attached to ESO’s Very Large Telescope, astronomers have been able to examine the inner protoplanetary disks around three interesting stars, with results showing the sheer diversity of the apparently emerging systems. Only a few million years old, all three stars could be considered analogs of our own Sun, going through processes [...]

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Tracing Our Interstellar Relatives

September 12, 2008

The idea that life on Earth might have originated elsewhere, on Mars, for example, has gained currency in recent times as we’ve learned more about the transfer of materials between planets. Mars cooled before the Earth and may well have become habitable at a time when our planet was not. There seems nothing particularly outrageous [...]

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Centauri Flyby: The Ultimate X Prize?

September 11, 2008

What should be the goals of the next generation of X Prizes? Peter Diamandis is just the man to ask the question. It was Diamandis’ foundation that led to the launch of a private manned spacecraft in 2004, and since then his team has gone on to sponsor an automotive X Prize offering $10 million [...]

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Gamma-Ray Burst Aimed Directly at Earth

September 10, 2008

A massive gamma-ray burst detected last March, believed to be the brightest ever seen, turns out to have been aimed directly at the Earth. A narrow jet that drove material toward us at 99.99995 of the speed of light is revealed in the data, itself wrapped within a somewhat slower and wider jet. The best [...]

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Sailing Messenger to a Mercury Encounter

September 9, 2008

Who would have thought the planet Mercury would prove so useful in explaining how solar sails work? The Messenger spacecraft’s recent course adjustment maneuvers have proven unnecessary because controllers have been able to use its solar panels creatively, harnessing solar radiation pressure (SRP). And what better place to shake out such methods but on your [...]

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Cepheid Variables: A Galactic Internet?

September 8, 2008

Making contact with an extraterrestrial civilization, whether by microwave, laser or neutrino, highlights the problem of time. Suppose you are looking for a newly emerging technological culture around another star. When do you transmit? After all, even the most powerful signal sent to Earth a million years ago would have no listeners, which is why [...]

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First Images from Steins Flyby

September 7, 2008

Fine work by Rosetta on the Steins flyby. Check here for more imagery of the ‘diamond in the sky,’ with cratering suggesting extreme age. Image: Asteroid Steins seen from a distance of 800 km, taken by the OSIRIS imaging system from two different perspectives. The effective diameter of the asteroid is 5 km, approximately as [...]

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