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[Centaur]

NASA’s Dawn spacecraft was scheduled to begin orbiting asteroid 4 Vesta earlier today (2011 JUL 16): www.nasa.gov/mission_pages/dawn/news/dawn20110714.html . We should learn tonight if it succeeded.

Vesta is the brightest of the asteroids and is currently naked-eye visible under dark skies at magnitude + 5.3 in Capricornus. Perigee (closest to Earth) of 1.228 AU will occur on AUG 01. Its greatest brilliance of magnitude +5.2 is expected on AUG 03 with opposition from the Sun on AUG 05.

Interestingly asteroid 9 Metis will achieve its greatest brilliance on the same day as Vesta, AUG 03. Other upcoming dates for the greatest brilliance of major asteroids are 2 Pallas on AUG 25, 192 Nausikaa on SEP 05 and the biggest one, 487-kilometer wide 1 Ceres, on SEP 16. The latter is also scheduled for an eventual visit by the Dawn spacecraft.

400-meter wide asteroid 2005 YU55 will pass Earth by 85% of the distance to the Moon on NOV 08. At about a billionth of the mass of Ceres, it’s not exactly a “huge asteroid” as proclaimed in the sensationalist media. I’d call it a huge meteoroid.

I have charts for all of the above asteroids at www.CurtRenz.com/asteroids . For the last one I provide an animation.

Photos and descriptions of these asteroids would be welcome additions to this thread.

[Centaur]

Entry into orbit around Vesta was indeed a success early this morning: www.nasa.gov/mission_pages/dawn/news/dawn20110716.html

[Chicago Astronomer - Astro Joe]

The first image is cool...

How interesting... the logistics involved to orbit a tiny rock way out there.

Hans Solo did it first though.

[Paulie pchris00]

Vesta is the first asteroid I ever saw, ad the only one I was able to observe over several days to be sure of it's motion. There are several asteroids on the Calumet Astronomical Society's 2011 Solar System Observing list, but so far this year I've only caught 44 Nysa(?). Vesta and Ceres will be on be list for the Indiana Family Star Party at the end of the month, and possibly others. Will have to print charts before heading down there, since I doubt I can use my laptop in the observing field.

[Chicago Astronomer - Astro Joe]

I have only observed Ceres, in a 10" Dob during a all night long private star party in Woodstock Illinois.

Let's grab Vesta in the C11, perhaps at our private observation site.