A pond of frozen nitrogen on Pluto

After studying Ceres for more than eight months from its low-altitude science orbit, NASA’s Dawn spacecraft will move higher up for different views of the dwarf planet.

A team of scientists has documented atmospheric changes on Io, Jupiter’s volcanically active satellite, as the giant planet casts its shadow over the moon during daily eclipses. Io’s thin atmosphere collapses as the sulfur dioxide gas emitted from volcanoes freezes when shaded by Jupiter. The atmosphere reforms when Io moves out of eclipse and the ice sublimates.

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.