Ceres

[Christopher K.]

The Texas-sized (975 x 909 km) spheroid known as Ceres was discovered in January 1801 by Guiseppe Piazzi. Piazzi was searching the area between the orbits of Mars and Jupiter for planets, and indeed Ceres was in the planet "column" until more and more objects were discovered in the same region and the category of asteroid was born. In 2006, Ceres (and Pluto and Eris) was designated a dwarf planet by the IAU. However, another suggestion that year would have brought Ceres back to a planetary classification.

Along with Vesta, Ceres will be an observing target of the Dawn mission. That spacecraft should arrive in Ceres' vicinity in February 2015.

More information:
http://solarsystem.nasa.gov/planets/pro ... =Dwa_Ceres

About Dawn:
http://www.nasa.gov/mission_pages/dawn/ceresvesta/

[Christopher K.]

The Dawn spacecraft has entered orbit around Vesta, and today completed the "spiraling" required to put itself into a surveying orbit. The operations team will now make final adjustments if needed before Dawn starts observations a week from Thursday.

Ceres can expect an arrival from Dawn in February 2015. The spacecraft will stay until that July.

[Christopher K.]

New analysis confirms there is water either on or in Ceres! This is the first for-certain detection of water vapor around an object in the asteroid belt.

More information:
http://www.skyandtelescope.com/news/home/241639001.html

The European Space Agency press release of 22 January:
http://www.esa.int/Our_Activities/Space ... anet_Ceres

[Christopher K.]

Ceres is shown like never before in the 20 January APOD. A twenty-frame video taken by the approaching Dawn spacecraft shows a mysterious (and very obvious) bright patch during the asteroid's rotation.

20 January APOD:
http://apod.nasa.gov/apod/ap150120.html

[Christopher K.]

The mystery of Ceres' bright spots persists. Dawn has found now many more than the initial two. Ceres is darkish and has a lot of craters; I believe it resembles Mercury more than our Moon.

18 February APOD, showing many of the bright spots:
http://apod.nasa.gov/apod/ap150218.html

[Christopher K.]

Yesterday was the 214th anniversary of Giuseppe Piazzi's discovery of Ceres. At this time Ceres is in Capricornus, 048' northeast of the G-class, magnitude 5.2 star 41 Capricorni. It is now beyond any useful span of times to view Ceres. Tomorrow night twilight ends at 6:42pm and Ceres is then only fourteen degrees up, sinking lower in the west night by night.

Ceres crosses into Aquarius on the night of 14 January.

[Christopher K.]

On 29 April (International Astronomy Day!) Dawn took advantage of the brighter Ceres surface due to its opposition and got several images that are now fashioned together as a video. Dawn's distance was about 20,000 kilometers.

More information:
https://www.nasa.gov/feature/jpl/movie- ... n-from-sun