These are exciting times for skywatchers. First, we’ll have a celestial guest in the form of asteroid 2005 YU55, which will slip in between Earth and the Moon tomorrow but presents no danger to us at all. It’ll be some 200,000 miles (320,000 kilometers) away at its closest approach, so still fairly distant. The rock itself is pretty dark but should still be visible through a medium-size telescope (6 to 8 inches), shining at magnitude 11.1.
But if you’re itching for some excitement right now, and are located south of the equator, the Phobos-Grunt project could use your help. Because the probe’s boosters will fire out of view from Russia, the team leaders are inviting amateur astronomers in South America to observe two rocket burns, providing data to ensure everything’s going well with the mission’s trajectory.
Observers can report their findings at http://phobos.cosmos.ru/index.php?id=1686&L=2 (registration required). The first burn should take place tomorrow at 22:55 GMT and last for about 9½ minutes, while the second burn is scheduled for November 9 at 1:02 GMT for about 17 minutes. Both will be visible pretty much only from South America and parts of the South Pacific. If you plan to participate, you’ll need to report your data as soon as possible to help the Phobos-Grunt team. (Find viewing tips at http://satobs.org/seesat/Nov-2011/0031.html.)
(Special thanks to James Oberg, who helped out with this blog post and wrote about a similar issue in the July 2002 issue of Astronomy.)