NASA is nearing a watershed moment in space exploration. On March 6, the Dawn spacecraft will begin to orbit Ceres, marking the first time man has ever explored a dwarf planet. In the meantime, Dawn has sent back some tantalizing images.
“Dawn is about to make history,” said Robert Mase, project manager for the Dawn mission at NASA’s Jet Propulsion Laboratory in Pasadena, California. “Our team is ready and eager to find out what Ceres has in store for us.”
Scientists want to know what, if anything, is active on Ceres. The first object discovered in the asteroid belt, recent images reveal that the protoplanet is positively lousy with distinctive features, including two mysterious bright spots that scientists have still yet to identify. Whether any of Ceres’ feature have changed will indicate to scientists whether or not there’s any geological activity.
Dawn also explored Vesta (a similar object, though not as large) for 14 months beginning in 2011. The more science learns about Ceres’ origins, the more it learns about the origins of the solar system itself.
“Both Vesta and Ceres were on their way to becoming planets, but their development was interrupted by the gravity of Jupiter,” said Carol Raymond, deputy project scientist at JPL. “These two bodies are like fossils from the dawn of the solar system, and they shed light on its origins.”
The differences between Vesta and Ceres are important as well. Ceres is obviously larger, and the largest object within the asteroid belt. But apart from size, Vesta appears to be very dry, while Ceres is believed to be about 25% water by mass. Since Vesta is the older of the two, scientists are keen to identify explanations for the differences in moisture.
“By studying Vesta and Ceres, we will gain a better understanding of the formation of our solar system, especially the terrestrial planets and most importantly the Earth,” said Raymond. “These bodies are samples of the building blocks that have formed Venus, Earth and Mars. Vesta-like bodies are believed to have contributed heavily to the core of our planet, and Ceres-like bodies may have provided our water.”
As for those vexing shiny spots on Ceres, the scientists assume they’re caused by highly reflective material, perhaps ice or salt deposits. Until Dawn gets close enough to take better images, though, no one knows for sure.