As NASA’s Dawn spacecraft speeds ever closer to the dwarf planet Ceres – the largest object in the asteroid belt – craters and mysterious bright spots are beginning to appear in the increasingly high resolution imagery.
They pose intriguing questions for the science team.
“As we slowly approach the stage, our eyes transfixed on Ceres and her planetary dance, we find she has beguiled us but left us none the wiser,” said Chris Russell, principal investigator of the Dawn mission, based at UCLA. “We expected to be surprised; we did not expect to be this puzzled.”
Dawn is expected to be captured into orbit around Ceres on 6 March. As the spacecraft delivers better images and other data, the science team will be investigating the nature and composition of the dwarf planet, including the nature of the craters and bright spots that are coming into focus.
Dawn explored the giant asteroid Vesta for 14 months during 2011 and 2012, providing invaluable insights into its geological history. By comparing Vesta and Ceres, they will develop a better understanding of the formation of the solar system.
Meanwhile, The Conversation looks at the discovery of Ceres:
Ceres was discovered on New Year’s Day in 1801, by Italian astronomer Giuseppe Piazzi, a member of an international team of astronomers dubbed the Celestial Police, who were searching for a supposedly missing planet in between the orbits of Mars and Jupiter. When discovered, Ceres was immediately recognized as a planet, the eighth one known at the time (neither Neptune nor Pluto had been discovered yet).
But within a few years, other objects in the asteroid belt were discovered and Ceres no longer seemed to stand out as far from the crowd. In 1802, the great astronomer William Herschel suggested that Ceres and Pallas and any other smaller solar system objects should be called asteroids – meaning star-like. In telescope images, they were so tiny that they looked point-like, like stars, rather than disk-like, like planets. And so, more than a century before Pluto was discovered, Ceres was plutoed.
Bill Condie is a science journalist based in Adelaide, Australia.
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