Monday, January 06, 2014
I wrote a post a long time ago on the closest approach distances for Ceres and Vesta to Earth before Dawn's arrival, and now there is but one left: April 2014, when Ceres will reach a fairly close 1.64 AU from us. That distance, coincidentally, is exactly the one Ceres was at when we obtained our best image of the minor planet back in 2004, the one that everybody is familiar with:
I had originally hoped for HST observations of Ceres back in 2009 but that never happened. However, with Dawn only a year away from arrival it is now much more important to know as much as possible about Ceres before arrival - Ceres could still have a tiny satellite or two or three, and Dawn has lost two of its reaction wheels which means a certain amount of extra care from home and less ability to spin about searching for objects on its own. Thus I am happy to have found an HST proposal for just this, a scheduling of HST time in April to observe Ceres again and perhaps find a satellite or anything else that may be relevant for the mission.
Whatever images we are able to obtain of Ceres from Earth will be the best we have until February 9 2015, when Dawn's images of the planet will begin to exceed those of the HST.