Ceres is a dwarf planet with a radius of 473 kilometers and it represents the largest object in the asteroid belt located between the orbits of Mars and Jupiter.
Using high spatial resolution data collected by the Gamma Ray Neutron Detector (GRaND) aboard NASA’s Dawn spacecraft, a team of planetary scientists have detected elevated concentrations of hydrogen in Occator Crater (a large and young woman 92 kilometers in diameter) and also in the surrounding area, which contains the most prominent bright spots of Ceres.
The work, published in the journal Geophysical Research Letters , shows the evidence through a new detailed map of the hydrogen concentration in the vicinity of Occator thanks to observations of elliptical orbits that brought the spacecraft very close to the surface during the final phase of The mission. The conclusions leave no room for doubt:
Has a lot of ice water
“The dwarf planet Ceres, the largest body in the main asteroid belt, is rich in water,” says Tom Prettyman, senior scientist at the Institute for Planetary Sciences. “The average interior structure of Ceres consists of a rocky mantle and a 40 km thick crust, dominated by the frozen remains of an ancient global ocean. Rheological limitations indicate that the crust is rich in volatiles, contains water ice, phyllosilicates , salts and possibly clathrate hydrates “.
The authors clarify that in the outermost portion of Ceres there is ice water that gradually sublimates in response to the heating of the surface by sunlight. These results thus confirm that the outer crust of the dwarf planet is rich in ice and that water ice can survive within the impact ejections in airless icy bodies.
“Since the axis of rotation of Ceres is almost perpendicular to the rays of the Sun, the ice has receded to greater depths at the equator than at the poles. We hypothesize that the impacts can bring icy water from the outer crust to the surface, replenishing the regolith with ice, ” the researchers continue.
Based on the results, the scientists suggest that the ice has survived in the shallow subsurface for approximately 20 million years after the formation of the young Occator crater that contains “Spot 5”, the brightest of the observed bright spots. by the Dawn spaceship.
“The impact that formed Occator would have excavated materials from the crust to a depth of up to 10 km. So the observed improvements in hydrogen concentration within the crater and ejection layer support our interpretation that the crust of the dwarf planet is ice-rich, “says Prettyman.
“More generally, as an ocean world, Ceres could be habitable and is therefore an attractive target for future missions, ” concludes the expert.
Referencia: T. H. Prettyman et al, Replenishment of Near‐Surface Water Ice by Impacts Into Ceres’ Volatile‐Rich Crust: Observations by Dawn’s Gamma Ray and Neutron Detector, Geophysical Research Letters (2021). DOI: 10.1029/2021GL094223