Though asteroids might look dry and barren from the outside, the Solar System’s biggest asteroid is unlike most as it may have been an ocean world. This is what NASA’s Dawn spacecraft discovered.
According to Thomas Prettyman, a nuclear engineer at the Planetary Science Institute in Tucson, Arizona, the asteroid was oozing with water billions of years ago. Prettyman led the team which built the neutron-counting instrument on the Dawn spacecraft.
Fast forward to today, the water has solidified, with scientists providing two possible scenarios. One possibility is that the water turned to ice and filled pore spaces found deep inside Ceres. It could also be that the water is locked inside hydrated minerals found at the surface. However, billions of years ago, the heat left from the formation of the Solar System likely kept the asteroid warm inside, allowing water to flow and separate Ceres into layers of rock and ice.
According to Carol Raymond, a planetary scientist at NASA’s Jet Propulsion Laboratory in Pasadena, and deputy principal investigator for NASA’s Dawn mission, “We know the water and the rock have separated and interacted over time”
This discovery helped provide awareness about Ceres being an active and wet world in its ancient years, and now it has a 4-kilometer high ice volcano as well as bright spots on the surface which is thought to be a mixture of ice and rock.
Ceres measures at 940 kilometers across, making it a huge asteroid that contains about one-third of all the mass in the asteroid belt. This technically makes Ceres a dwarf planet as well. Scientists determined that Ceres was water-filled based on its density, and also by looking at the light reflecting off the hydrated minerals on its surface. In addition, they found water steaming from the surface. However, they were not sure how much water it had until NASA’s Dawn spaceship shared its data on it.