AST 111 Lecture Notes - Lecture 14: Mariner 10, Caloris Planitia, Runaway Greenhouse Effect
Document Summary
Mercury is cratered like the moon: nearly everything known about mercury has been learned using two spacecraft, mariner 10 made 3 flybys of the plaet in 1974/1975 and photographed. 45% of the planet"s surface: the messenger mission made 3 flybys before entering in to orbit in march. Each flyby also orbitied the sun (every 176 days) so its orbit aligned. A scarp is a long, cliff-like feature. Thought to be formed by the cooling and cracking of the planet"s surface: shown because the angles of the scarps are consistent with, the caloris basin shrinkage. A bullseye shaped impact crater with rings of mountain ranges surrounding it. The hottest portion of mercury when it is nearest the sun. On the opposite side of mercury, there is hilly terrain, probably formed when seismic waves from the impact that formed the basin spread through the center of the planet: water on mercury, magnetic field. Hidden in deep craters at the poles.
