March 2009

Saturnian Transits (and a Memory)

March 18, 2009

Every now and then a new space photo completely snares the attention. This one is a Hubble shot showing four of Saturn’s moons moving in front of the planet. Note Titan at the top, while below it from left to right are Enceladus, Dione and (at extreme right) Mimas. To see the smaller moons, you’ll […]

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Prospects for Red Dwarf ‘Earths’

March 17, 2009

Most stars in our region of the galaxy are low-mass M-dwarfs, making the investigation of their planetary systems quite interesting. If we learn that stars like these, which comprise over 70 percent of the galactic population, can be orbited by Earth-like planets, then the galaxy may be awash with such worlds. But some models have […]

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Interstellar Matters at UK Conference

March 16, 2009

Tau Zero practitioner Kelvin Long has organized an interstellar session at the forthcoming 2009 UK Space Conference, which will take place from April 1 to 4 at Charterhouse School, near Godalming Surrey. The overall conference looks to be an excellent one, with symposia on rocket technology, panels and presentations on astronomy and space science, much […]

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A New Tilt on SETI

March 14, 2009

The planets in our Solar System rotate around the Sun more or less in a plane (the ecliptic) that is tilted some sixty degrees with relation to the galactic disk. It’s interesting to speculate that this could have ramifications in terms of the SETI hunt. Shmuel Nussinov (Tel Aviv University) considers the possibility that any […]

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Mapping a Galactic Transit System

March 13, 2009

I love the London Underground and have a great fondness for wandering about the city with a tube map stuck in my pocket. My wife and I last did this a few years back, making an early March trip in which we rented a Bloomsbury apartment for ten days and hopped all over the area, […]

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How Many Stars in the Galaxy?

March 12, 2009

We’ve often speculated here about how many stars exist in the Milky Way. Earlier estimates have ranged from one hundred billion up to four hundred billion, with a few wildcard guesses in the range of one trillion. The number is still, of course, inexact, but recent work has led to a serious misunderstanding of the […]

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Rare Earth? Not Enough Data to Know

March 11, 2009

George Dvorsky takes on the ‘rare earth’ hypothesis in his Sentient Developments blog, calling it a ‘delusion’ and noting all the reasons why life in the galaxy is unlikely to be unusual. The post reminds me why the book that spawned all this was so significant. Rare Earth: Why Complex Life is Uncommon in the […]

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Browsing the Exoplanet Catalog

March 10, 2009

We now have on the order of 335 confirmed exoplanets, with an ongoing race between the CoRoT and Kepler teams to find the first Earth analog in the habitable zone around another star. CoRoT’s shorter observation cycles make finding a terrestrial world around a G-class star problematic — the orbit would necessarily be on the […]

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A Fine Intergalactic Haze

March 9, 2009

Take a look at NGC 4565, a spiral galaxy seen edge-on. Spiral galaxies viewed at this angle often show dark dust lanes, the result of dust from dying stars mixing with interstellar gas. We’ve discussed the problem of interstellar dust in terms of objects moving at relativistic speeds between stars, but recent quasar studies are […]

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Space Voyaging a Century Out

March 7, 2009

A nice, tidy liftoff for Kepler, and like all night launches, well worth watching. The mission is generating a satisfying amount of attention in the press and a slew of news releases, from one of which which I’ll quote Geoff Marcy: “In part, learning about other Earths — the frequency of them, the environment on […]

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