New images captured by NASA’s Dawn spacecraft from a distance of 240 miles (385 km) show two prominent craters on the surface of Ceres: Oxo and Haulani.
This image is a mosaic of views that Dawn took in its low-altitude mapping orbit, at a distance of 240 miles (385 km) from the surface of Ceres. In the center is Haulani Crater. Image credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI.
The bluish material visible in this enhanced-color image of Haulani Crater indicates relatively fresh material on the surface. Image credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI.
With a diameter of 21 miles (34 km), Haulani Crater shows evidence of landslides from its rim. Smooth material and a central ridge stand out on its floor.
An enhanced color view allows members of the Dawn science team to gain insight into materials and how they relate to surface morphology. It shows rays of bluish ejected material.
“This material represents flow structures and was most probably caused by an interaction between the direct surface and the material lying directly below,” said Dr. Ralf Jaumann of the German Aerospace Center.
“It follows, therefore, that beneath the ice-free surface of Ceres, there must be another, different layer. There are indications that this layer, situated under the uppermost crust, is enriched with ice and volatile substances.”
Dr. Martin Hoffmann of the Max Planck Institute for Solar System Research in Göttingen, Germany, added: “Haulani perfectly displays the properties we would expect from a fresh impact into the surface of Ceres. The crater floor is largely free of impacts, and it contrasts sharply in color from older parts of the surface.
Haulani’s polygonal nature is noteworthy because most craters seen on other planetary bodies, including Earth, are nearly circular.
The 6-mile-wide Oxo Crater is the second-brightest feature on Ceres. Dawn took this image in its low-altitude mapping orbit. Image credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI.
Oxo Crater, according to the team, is the second-brightest feature on Ceres.
It has a diameter of 6 miles (10 km) and lies near the 0 degree meridian that defines the edge of many Ceres maps, making this small feature easy to overlook.
Oxo is also unique because of the relatively large ‘slump’ in its crater rim, where a mass of material has dropped below the surface.
The scientists are also examining the signatures of minerals on the crater floor, which appear different than elsewhere on Ceres.
“Little Oxo may be poised to make a big contribution to understanding the upper crust of Ceres,” said Dr. Chris Russell from the University of California, Los Angeles.
