Spacing out

As the year wraps up, some miscellaneous space news ...

One of the most fascinating results to come from the Apollo program concerned the longstanding puzzle of the origins of Earth's moon. (Our moon is anomalous, most visibly because it is so large compared to the planet it orbits.) The conclusion, based upon rock samples collected on the lunar surface: the moon likely resulted from the cataclysmic collision of a Mars-sized object with the (then very young) Earth.

This year's semi-related news item concerns Phobos, Mars's largest (but still tiny) moon. (The nearby picture is a [color-enhanced] image of Phobos taken by the Mars Reconnaissance Orbiter.) Phobos likely formed from a smaller impact with Mars itself.

The space-shuttle fleet will be retired in 2011. For the foreseeable future, the US will have to pay the Russians for crew rides to the International Space Station. As disappointing as is that situation (I've commented on it before), at least getting supplies to the International Space Station aboard American spacecraft just became more credible with the successful test flight of Space-X's Dragon.

For those of you wondering when the next dinosaur-killer-class asteroid is due, some new data. NASA's Wide-field Infrared Survey Explorer (WISE) space telescope found -- among other interesting things -- ~25,000 new asteroids, 95 of them classified as near-Earth objects, during its first six months of operation. None of the newly spotted objects is considered a threat to Earth. The statistics of the survey are encouraging.

Looking further ahead, DARPA (with a small contribution from NASA) is starting to look at how to build a starship. See: The Hundred Year Starship fund.

And here's a neat new way to find small exoplanets. As exoplanet hunting goes, one of the older search methods (and the method used by NASA's Kepler mission) looks for periodic dimming attributable to large planets crossing in front (from Earth's point of view) of stars. The transit timing variation method looks at changes in such transit times attributable -- after lots of computation -- to the tug of planets to small to be detected directly.

I didn't intend this post as any sort of year-end summary, but if you're in the market for such a thing, here's Space.com's list of top 2010 space stories.