“Between the orbits of Mars and Jupiter is a mysterious dwarf planet called Ceres. Its surface is dark and muddy, but has hundreds of patches of bright material. The salt-covered dome and other bright features in Occator Crater are so reflective that they looked like flashlights in distant images. NASA’s Dawn spacecraft got a close look at Ceres and pointed scientists to the idea that liquid brine has come up from the interior, forming the Occator dome and other bright features. Ceres’ crust also contains a significant amount of ice. Astrobiologist Britney Schmidt discusses the implications, as well as her fieldwork in Antarctica.”
Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter and the only dwarf planet located in the inner solar system. It was the first member of the asteroid belt to be discovered when Giuseppe Piazzi spotted it in 1801. And when Dawn arrived in 2015, Ceres became the first dwarf planet to receive a visit from a spacecraft.
Called an asteroid for many years, Ceres is so much bigger and so different from its rocky neighbors that scientists classified it as a dwarf planet in 2006. Even though Ceres comprises 25 percent of the asteroid belt’s total mass, tiny Pluto is still 14 times more massive.
Ceres is named for the Roman goddess of corn and harvests. The word cereal comes from the same name.
Size and Distance
With a radius of 296 miles (476 kilometers), Ceres is 1/13 the radius of Earth. If Earth were the size of a nickel, Ceres would be about as big as a poppy seed.
From an average distance of 257 million miles (413 million kilometers), Ceres is 2.8 astronomical units away from the sun. One astronomical unit (abbreviated as AU), is the distance from the sun to Earth. From this distance, it takes sunlight 22 minutes to travel from the sun to Ceres.