Planetary astronomer Mark Showalter at the SETI Institute is rabid about rings. While everyone knows about Saturn’s spectacular ring system, it’s often forgotten that Jupiter, Uranus and Neptune are also encircled by fainter and narrower rings. Each of these systems interacts closely with a family of small, inner moons. These ring-moon systems provide our best analogs for understanding the formation and evolution of planets around stars.
Showalter works on some of NASA’s highest-profile missions to the outer planets, including Cassini, now orbiting Saturn, and New Horizons, which recently flew past Jupiter en route to its 2015 encounter with Pluto. His work on the earlier Voyager mission led to his discovery of Jupiter’s faint, outer “gossamer” rings and Saturn’s tiny ring-moon, Pan.
Since 2002, Mark has been leading a team of astronomers using the Hubble Space Telescope to study Uranus, and his work has already led to the discovery of two small moons and two faint rings.
