Colour-coded map indicating Ceres’ rich topography. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
The surface of Ceres contains a diverse topography with height differences ranging as much as 15km between crater bottoms and mountain peaks, according to new maps of the dwarf planet captured by NASA’s Dawn spacecraft.
Dawn is currently undertaking a decade-long mission to study the asteroid Vesta and dwarf planet Ceres, both of which are believed to have formed early in the life of the Solar System.
Ceres has a diameter of 940km, making it the largest object in the main asteroid belt, which is located between the orbits of Mars and Jupiter.
It is about 40 per cent the size of fellow dwarf planet Pluto.
Newly labelled features on Ceres include Occator, a crater containing bright spots and with a diameter of about 90km and a depth of about 4km.
The small crater previously called ‘Spot 1’ is now called Haulani, after the Hawaiian plant goddess. Haulani has a diameter of about 30km.
Data from Dawn’s visible and infrared mapping spectrometer indicates Haulani is colder than most of the territory around it.
Animation showing a colour-coded map from the Dawn mission. The colour scale extends 6km below the surface in purple to 6km above the surface in brown. Credit: NASA
“The craters we find on Ceres, in terms of their depth and diameter, are very similar to what we see on Dione and Tethys, two icy satellites of Saturn that are about the same size and density as Ceres.
The features are pretty consistent with an ice-rich crust,” says Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston.
“The impact craters Dantu and Ezinu are extremely deep, while the much larger impact basins Kerwan and Yalode exhibit much shallower depth, indicating increasing ice mobility with crater size and age,” says Ralf Jaumann, a Dawn science team member at the German Aerospace Center (DLR) in Berlin.
Dawn is now moving into its third science orbit, just under 1,500km above the surface and three times closer to Ceres than its previous orbit.
It will reach this orbit mid-August and begin taking images and collecting further data.
Dawn reached Ceres on March 6, 2015, making it the first mission to reach a dwarf planet and the first to orbit two distinct extraterrestrial targets.
It conducted observations of Vesta in 2011-2012.