Rosaly Lopes is an expert in planetary volcanism at NASA's Jet Propulsion Laboratory in Pasadena, California, where she studies volcanism on Earth, as well as other planets and moons. Using data returned by the Galileo spacecraft, Dr Lopes was responsible for the discovery of 71 previously unknown volcanoes on Jupiter's moon Io. She currently works on the Cassini mission, which is making observations of Saturn and its moons.