NASA has released the closest images ever captured by its Dawn mission spacecraft in orbit around the dwarf planet Ceres.
The new images are the most detailed of the tiny world's surface ever taken, showing craters, fractures and fissures, and were snapped by the Dawn probe during its lowest and final orbit about Ceres.
The images of its southern hemisphere were taken at an altitude of around 240 miles in an orbit that Dawn will occupy for the remainder of its mission, NASA says. Ceres lies in the asteroid belt between the orbits of Mars and Jupiter.
At a resolution of around 120 feet per pixel, the photos offer impressive views of a string of craters dubbed Gerber Catena.
They also show features usually seen on larger planet bodies, such as canyons or troughs normally caused by impact stresses, contraction, and the deformation of a surface curst by large mountain formations.
The fractured nature of the surface of Ceres suggests similar processes have happened there, despite the dwarf planet's tiny size of just 584 miles across, scientists say.
"Why they are so prominent is not yet understood, but they are probably related to the complex crustal structure of Ceres," says Paul Schenk, mission science team member from the Lunar and Planetary Institute in Houston.
While many of the fissures and fractures on Ceres were probably formed by impacts, some of them appear to show signs of a tectonic origin, suggesting stresses within the dwarf planet that broke through the crust, mission researchers say.
"As we take the highest-resolution data ever from Ceres, we will continue to examine our hypotheses and uncover even more surprises about this mysterious world," says Chris Russell, Dawn mission principal investigator based at the University of California, Los Angeles.
Dawn has a number of different instruments involved in analyzing Ceres, including a visible and infrared mapping spectrometer to identify minerals by seeing how various wavelengths of light reflect off the surface, and a gamma ray and neutron detector to look for radiation that can provide evidence about the abundances of some elements on the dwarf world.
The Dawn mission is the first to survey a dwarf planet, as well as the first to orbit two separate solar system targets other than the Earth and moon, orbiting the protoplanet Vesta for 14 months in 2011 and 2012, then moving on to arrive at Ceres in March 2015.