If the Obama administration is looking for an asteroid worth a human visit, how about 24 Themis? As recently reported in the journal Nature, this asteroid between Mars and Jupiter was recently found to contain water and maybe even some organic molecules. This adds further support to the idea that asteroids and comets brought life to our planet.Another asteroid probably more worthy of a visit is Ceres. A prior Nature article noted that various images from the Hubble telescope led scientists to believe the asteroid Ceres may contain more fresh water than Earth. Ceres is 580 miles (930 km) in diameter (about the size of Texas) and represents about 25-30 percent of the asteroid belt's total mass. In fact, for about a century the asteroid was classified as a planet (see image for size comparisons with the Earth and the moon). NASA already has a spacecraft expected to encounter Ceres in 2015 (as well as the asteroid Vesta in 2011) - the Dawn Mission. Will humans follow?
