A spectacular sampling of imagery from NASA’s New Horizons spacecraft reveals mountains and water ice bedrock on Pluto, an active crust on its largest moon Charon and the first resolved views of the icy world’s tiny mini-moons.
A snapshot of Pluto shows fresh deposits of water ice bedrock and 11,000-foot (3500-metre) mountains, revealing evidence Pluto’s surface is one of the youngest in the solar system. These mountains likely formed no more than 100 million years ago, suggesting the close-up region — which covers about one percent of Pluto’s surface — may still be geologically active today. Unlike the icy moons of giant planets, Pluto cannot be heated by gravitational interactions with a much larger planetary body. Some other process must be generating the mountainous landscape. Photo credit: NASA/JHUAPL/SWRINew Horizons found few craters on the surface of Pluto’s Texas-sized moon Charon, evidence of recent geologic activity. A swath of cliffs and troughs stretching about 600 miles (1,000 kilometres) suggests widespread fracturing of Charon’s crust, likely the result of internal geological processes. The image also shows a canyon estimated to be 4 to 6 miles (7 to 9 kilometres) deep. In Charon’s north polar region, the dark surface markings have a diffuse boundary, suggesting a thin deposit or stain on the surface. Photo credit: NASA/JHUAPL/SWRITuesday’s New Horizons flyby revealed Pluto’s tiny moon Hydra. The first resolved image of the object shows it to be 28 miles long and 19 miles in diameter, and better images are to come. The observations also indicate Hydra’s surface is probably coated with water ice. Photo credit: NASA/JHUAPL/SWRI
A new model developed by University of Rochester researchers could offer an explanation as to how cracks on icy moons, such as Pluto’s Charon, formed. Until now, it was thought that the cracks were the result of geodynamical processes, such as plate tectonics, but computer simulations suggest that a close encounter with another body might have been the cause.
Backlit by the Sun, Pluto’s atmosphere rings its silhouette like a luminous halo in this image taken by NASA’s New Horizons spacecraft on July 15. This global portrait of the atmosphere was captured when the spacecraft was about 1.25 million miles (2 million kilometres) from the dwarf planet.
New Horizons science team members give personal accounts of their work during the Voyager Neptune encounter and their new assignments on the Pluto mission.
