October 2007

Binaries, Gas Giants and Habitable Worlds

October 19, 2007

Alpha Centauri A and B have a mean separation of 23 AU. In Solar System terms, that gives you a spacing a bit further from the Sun than the orbit of Uranus. But with the two stars moving around a common center of mass, the distance between them varies over time. Centauri B is sometimes […]

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Best Glimpse Yet of Nix and Hydra

October 18, 2007

Thirty years ago it was all but impossible to tease the presence of Charon out of the Pluto images available to astronomers. Today we’re using ground-based telescopes like the twin Keck instruments on Mauna Kea (Hawaii) to see the far tinier Nix and Hydra, the minute satellites discovered by the Hubble Space Telescope in 2005. […]

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Carnival of Space #25

October 18, 2007

Sam Wise offers the latest Carnival of Space (#25) on his Sorting Out Science blog, which if you haven’t seen (I hadn’t) you must. We’re obviously dealing with a voracious reader, for what we have here is a collection of noteworthy topics — the Allen Telescope Array, asteroid deflection and Cassini findings are particularly germane […]

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M87’s Jet (and Memories of Clarke)

October 17, 2007

The massive galaxy M87, the central object of the Virgo cluster, has drawn our attention for a long time. It was in 1918 that Heber Curtis discovered a jet pushing at least 5000 light years away from the center of the galaxy. In 1949, the radio source Virgo A was identified with M87, and by […]

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Amateur Discovers GRB Afterglow

October 16, 2007

What we know about gamma-ray bursts is dwarfed by what we don’t, but chipping away at the problem is getting us places, particularly with the help of amateur astronomers. Thus the news that Finnish amateur Arto Oksanen had found the optical afterglow of GRB 071010B, a gamma-ray burst detected by NASA’s Swift satellite. Oksanen did […]

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SETI’s Dilemma: Break the Great Silence?

October 15, 2007

When Alexander Zaitsev presented his recent paper at the International Astronautical Congress in Hyderabad (India) recently, he spoke from the center of a widening controversy. The question is straightforward: Should we broadcast messages intentionally designed to be received by extraterrestrial civilizations, thereby notifying them of our existence? Zaitzev, chief scientist at the Russian Academy of […]

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Dark Energy’s Clues

October 13, 2007

Fifty years ago, our understanding of space included only some of the properties we now find most intriguing from the standpoint not only of physics but also of potential propulsion. Dark energy was not suspected then, while Fritz Zwicky’s inference of dark matter (1933) wouldn’t really inspire a wave of investigations until the 1970’s. The […]

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Allen Telescope Array Begins Work

October 12, 2007

The Allen Telescope Array, devoted both to SETI and astronomical observations, has begun operations. With 42 radio dishes now active, the array ultimately will be used to scan several billion stars in the Milky Way looking for the signals of an extraterrestrial civilization. That’s a staggeringly broad survey, and one that will be followed up […]

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Morning Drizzle at Xanadu

October 11, 2007

Xanadu seems to be a misty, drizzly place. So say new images showing a persistent light rain of methane over the western foothills of this, the major continent of Titan. Titan’s day is sixteen Earth days long, so if we say the drizzle or mist dissipates after about 10:30 AM local time, we’re saying that […]

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New Horizons: Volcanic Plumes on Io

October 10, 2007

Ever since the launch of New Horizons in January of 2006 (can it really be that long?), the prospects of doing good science as the spacecraft whipped through the Jupiter system have tantalized and intrigued us. Eight spacecraft have now visited Jupiter, but New Horizons found things no previous mission had witnessed, including the evolution […]

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