Two hundred and fourteen years ago, on Jan. 1 1801, the discovery of a faint celestial body set the stage for one of the biggest arguments in astronomy — planetary classification. Ceres, an asteroid the size of Texas, was known as the solar system’s largest rock for nearly two centuries. Until 2006, when a debate on the planetary status of Pluto called for a reclassification of Ceres to dwarf planet status. NASA launched Dawn shortly after in 2007, with a goal of further investigating this enigmatic world. The spacecraft has now begun its approach phase, and is expected to enter into orbit around Ceres in March.
NASA’s Dawn spacecraft launched atop a United Launch Alliance (ULA ) Delta II rocket from Space Launch Complex 17-B at NASA’s Kennedy Space Center on Sept. 27, 2007, kicking off the start of a seven year trek across the solar system.
Its mission: explore the asteroid belt and help unlock the secrets of the early solar system. Researchers had two targets picked out for the probe, and asteroid named Vesta and a dwarf planet named Ceres. Earlier this month, Dawn made headlines after capturing its first image of Ceres.
“Ceres is almost a complete mystery to us,” said Christopher Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles. “Ceres, unlike Vesta, has no meteorites linked to it to help reveal its secrets. All we can predict with confidence is that we will be surprised.”