February 2009

One Hundred Billion Trillion Habitable Planets

February 17, 2009

Alan Boss, whose new book The Crowded Universe will soon be on my shelves (and reviewed here), has driven the extrasolar planet story to the top of the news with a single statement. Speaking at the American Association for the Advancement of Science’s annual meeting in Chicago, Boss (Carnegie Institution, Washington) said that the number [...]

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Cosmic Inflation in Context

February 16, 2009

Cosmic inflation, first proposed by Alan Guth (MIT) in 1979, seems about as intractable a subject as dark energy. How to study it? Inflation does something mind-bending to spacetime by making it expand far faster than the speed of light. Oddly, this doesn’t contradict anything Einstein said, because while nothing we know can travel faster [...]

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Fireball Linked to Cometary Debris

February 14, 2009

Comet C/1919 Q2 Metcalf catches the attention. The intriguing object was discovered in August of 1919 and remained visible until early 1920, but no subsequent observations have been made. In 1973, Allan Cook discovered that the Omicron Draconids meteor stream seemed to be following the orbit of the earlier comet. Suspicion is strong that the [...]

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MEarth: Searching for Habitable ‘Super-Earths’

February 13, 2009

Will the first ‘super-Earth’ in the habitable zone of its star be found around a red dwarf? An M5-dwarf with both mass and radius about a quarter that of the Sun would have 1/200th Sol’s luminosity. That’s interesting for transit purposes, for a planet in the habitable zone around this star would be close in [...]

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Deep Questions About an Impact

February 12, 2009

Things move around in the story queue here, but occasionally a particular item almost gets past me before I remember to cover it. Such is the recent work on the possible impact event some 12,900 years ago, which Richard Firestone (Lawrence Berkeley Laboratory) and colleagues have argued would have contributed to the extinction of such [...]

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Interstellar Strategy: Spreading the Word

February 11, 2009

by Tibor Pacher My friend Tibor Pacher is joined with me (until 2025, anyway) in our ‘interstellar bet,’ under the auspices of the Long Now Foundation. Trained as a physicist at the Eötvös University in Budapest and the University of Heidelberg, Dr. Pacher has been exploring ways to get across interstellar concepts to the public [...]

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361 Civilizations in the Galaxy?

February 10, 2009

I promised a quick return to recent work on the Drake Equation, which helps us estimate the number of communicating civilizations in the galaxy, but a BBC story on Duncan Forgan has me back at it even sooner than I had intended. It’s no surprise that the matters encapsulated in Drake’s thinking should be in [...]

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Dust Up Between the Stars

February 9, 2009

Almost four years ago I wrote a Centauri Dreams entry about Dana Andrews’ views on shielding an interstellar spaceship. The paper is so directly relevant to our recent discussion on the matter that I want to return to it here. Andrews (Andrews Space, Seattle) believes that speeds of 0.2 to 0.3 c are attainable using [...]

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Dissent on Drake

February 7, 2009

Centauri Dreams‘ recent post on the Drake Equation triggered a broad range of response, both in comments and back-channel e-mails, the latter of which produced a note from Kelvin Long quoting a rather controversial position on Drake by one leading scientist. Here it is. See if it raises your hackles: “I reject as worthless all [...]

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Interstellar Flight: The Dust Conundrum

February 6, 2009

It would be helpful if space were a bit more empty. A key problem facing an interstellar probe would be encounters with dust in the planetary system it leaves and, as it reaches cruising speed, dust impact in space between the stars. Although our Solar System seems to be in an unusually sparse pocket of [...]

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