Phobos-Grunt has returned to Earth, a lot sooner than it should have. Yesterday, at approximately 17:45 UT, the Russian spacecraft and its passengers, including a Chinese orbiter and the Planetary Society's LIFE experiment, descended into Earth's atmosphere. The Russian military quickly announced that the mission was over, mentioning a precise time and location (17:45 and 1,250 kilometers west of Wellington Island, Chile, near the southern tip of South America). But that time and location was based upon model calculations, not on any actual detection of the spacecraft's reentry. According to journalist Jim Oberg, the spokesman actually said "From calculated data of the main space surveillance center of the Space Troops, the fall of fragments of F-G should have occurred at 21:45 Moscow Time..." (emphasis Jim's). Because of uncertainty in those models, it's possible the spacecraft entered the atmosphere a bit earlier or later; it could have fallen in the Pacific, or over a wide swath of South America or even in the western Atlantic ocean. So far, no credible reports of sightings or debris have surfaced, and it's likely (as happened with UARS and ROSAT) that we'll never know precisely where the spacecraft fell. The world is a big place, and is sparsely inhabited. It is especially sparsely inhabited in the far southern Pacific Ocean, which contains a large swath of the possible reentry locations. The following map of possible reentry locations was produced by Robert Christy and posted on his zarya.info website.
It seems there is not a lot more to be said. However, the European Space Agency cryptically promised an "update on Phobos-Grunt reentry, including an analysis on the reentry time and location" early this morning, and that it would be available "shortly." I held this post for several hours, hoping for that update to appear, but it hasn't. So there still may be some more detailed information available that's not yet been published.
Yesterday morning, as I was sitting deathwatch at my computer, Phil Plait invited me to participate in a Google+ Hangout with him to talk about the end of Phobos-Grunt; you can watch the recording below. (I exited the Hangout partway through in order to take care of some things for my kids, but returned about ten minutes later.) One of the points I tried to make was that Phobos-Grunt may have failed, but there are a lot of successful Mars missions currently flying: the venerable Mars Odyssey (longest-lived Mars mission ever), the rover Opportunity, the European orbiter Mars Express (which is studying Phobos in depth), and Mars Reconnaissance Orbiter. And, of course, Curiosity is on her way.
Google+ Hangout: Phobos-Grunt Re-entry On January 15, 2012, the Russian spacecraft Phobos-Grunt re-entered over the Pacific ocean and burned up. During this time, Phil Plait reported the event live with Emily Lakdawalla on a Google+ Hangout.