mercredi 16 septembre 2015, par Prof. Richard Binzel (MIT)
Jeudi 24 septembre 2015 à 16h00 , Lieu : Salle de conférence du bâtiment 17
After nearly two decades of struggling for approval, a NASA funded Pluto mission finally reached the launch pad in January 2006. Nine-and-a-half years later in July 2015, the piano-sized New Horizons spacecraft reached the Pluto system revealing an amazingly bizarre planetary world. Ice mountains as tall as the Alps and smooth plains of frozen carbon monoxide 500 km across are just some of the surprising features. Pluto appears to be a globally changing planet with seasonal cycles ranging from decades to millennia producing an evolving landscape of nitrogen ice glaciers and variable atmospheric pressure. Together with its largest satellite, Pluto and Charon form a “double planet” system orbiting a common center of gravity located outside of either body. Charon’s surface also appears relatively young and crater-free, implying some recent era geologic activity. Completing the system are four small moons found to be irregularly shaped with complex spin patterns in their own regularly spaced orbits. As New Horizons continues its voyage out of the solar system, a close encounter with at least one newly discovered Kuiper Belt object appears possible within the next four years.