Jupiter: April 2013

ESA's Herschel space observatory has solved a long-standing mystery as to the origin of water in the upper atmosphere of Jupiter, finding conclusive evidence that it was delivered by the dramatic impact of comet Shoemaker-Levy 9 in July 1994.

Jupiter's moon Io is the most volcanically active world in the solar system, with hundreds of volcanoes, some erupting lava fountains up to 250 miles high (about 400 kilometers). However, concentrations of volcanic activity are significantly displaced from where they are expected to be, based on models that predict how the moon's interior is heated, according to NASA and European Space Agency researchers.