The planned finale on Jun 30 of NASA's Dawn mission to dwarf planets Vesta and Ceres, which began in Sep 2007 and made history twice over, might not be the end for the mighty probe. The Dawn team has asked NASA to extend the mission to visit a third asteroid.
If the scientists receive permission, they will have to choose a celestial body that is relatively close to Ceres. The probe's propellant is dwindling, and a report about the proposed extended mission in New Scientist observes that limited fuel means fewer choices for a new target.
Scientists hope the mission will have answered questions about the composition of both bodies and explained the mysterious features on Ceres which include dazzling white spots on its surface and possible water vapour plumes.
The probe has been collecting pictures and data from just 230 miles above Ceres since Dec 22, 2015.
The spacecraft is the only one ever to orbit two destinations beyond Earth and the only one to orbit an object in the main asteroid belt between Mars and Jupiter.
Vesta has been confirmed as a fascinating world more closely related to the terrestrial planets (including Earth) than to typical asteroids. According to NASA, Dwarf planet Ceres, less dense and larger (590 miles in diameter) than Vesta (330 miles wide), is believed to have a large amount of ice and may even have subsurface liquid water. Ceres has the confirmed presence of water vapour in its thin atmosphere.
Date written/update: 2016-05-20