June 2006

Centauri Dreams in Deep Water

June 15, 2006

The remains of hurricane Alberto didn’t seem terribly menacing as they approached North Carolina, and much of the state got no more than a good soaking. But here in Raleigh we were inundated with over 7 inches in a short period of time, leaving Centauri Dreams with a flooded office. I’m back online, but only [...]

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Dyson Shells and the Astrobiological Imperative

June 13, 2006

Finding evidence of large-scale ‘macro-engineering’ projects around other stars may be our best chance of detecting other civilizations. So says Milan Ćirković (Astronomical Observatory of Belgrade) in a paper discussed here yesterday. But what would make us think such structures exist? Recent microlensing projects have found evidence of objects around distant stars — we can [...]

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Better SETI through Macro-engineering

June 12, 2006

If advanced technological civilizations are out there, how do we go about detecting them? Conventional SETI, beginning in 1960 with Frank Drake’s investigations of Tau Ceti and Epsilon Eridani, has focused largely on the reception of targeted information via radio. More recent optical SETI likewise hunts for beacons from a civilization attempting some form of [...]

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Optical Communications Success at JAXA

June 10, 2006

As we move up the frequency ladder toward optical communications, each step takes us closer to the kind of data traffic we’ll need for deep space missions into the Kuiper Belt and beyond. The idea is to pack as much information as possible into the signal. A stream of data transmitted from an antenna spreads [...]

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Cutting Through Interstellar Dust

June 9, 2006

When the British Interplanetary Society’s Daedalus designs were being created in the 1970s, the scientists and engineers involved quickly realized that interstellar dust would become a problem for a vehicle traveling at 12 percent of light speed. That led to shielding concepts involving materials like beryllium, boron and graphite. But what of concepts like Robert [...]

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Odd Carbon Abundance Around Beta Pictoris

June 8, 2006

Beta Pictoris, an A5 dwarf star some 63 light years from the Earth, is well known to exoplanet hunters, some of whom have been studying its circumstellar dust disk since its discovery by the Infrared Astronomical Satellite (IRAS). That disk was first detected way back in 1983, and is thought to be perhaps 1100 AU [...]

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Dark Matter and the Universe’s Expansion

June 7, 2006

Nobody can see dark matter, but the mysterious stuff can be detected because it influences large-scale structures like galaxies and galactic clusters. As far as we know, galaxies wouldn’t look the way they do without it. And studies of the cosmic microwave background lead to the belief that dark matter is five times more common [...]

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A New Take on Planetary Migration

June 6, 2006

It’s shaping up to be a good week for exoplanet findings, with yesterday’s intriguing work on ‘planemos’ and their disks and now, also presented at the AAS Calgary meeting, word of new findings on planetary migration. This is a significant issue, because so many of the exoplanets we know about are huge ‘hot Jupiters’ in [...]

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Miniature Planetary Systems May Be Common

June 5, 2006

Centauri Dreams marvels at the growth of the new lexicon whose definitions routintely fill these pages. Just the other day we encountered ‘mascon’ — a concentration of mass denoting the presence of a long-obscured crater. Today we get ‘planemos’ — planetary mass objects that float freely through space rather than orbiting a star. The latter [...]

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Reconstructing the Pioneer Anomaly

June 3, 2006

New Scientist is running an interesting piece [subscription required for full access] on Slava Turyshev (JPL), who plans to investigate the so-called Pioneer Anomaly by re-flying the mission virtually. It’s a fascinating tale for various reasons, not the least of which is how close we came to losing much if not all of the precious [...]

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