GEOLOGY 103 Lecture Notes - Lecture 12: Mariner 10, Mare Imbrium, Calorie
Document Summary
Mercury: diamater: 4880 km, gravity: 38% of earth, atmosphere: trace. History of investigation: too close to the sun for useful observations by earth-based telescopes, earth-based radar data, mariner 10 imaged 45% of surface, messengers: 3 ybys 2008-2009, orbited 2011-2015; now 100% coverage. Getting to mercury is dif cult: deep in the sun"s gravitational well". Spacecraft must decelerate: direct ight would take more fuel than needed to escape the solar system, very, very hot. Mercury"s surface: like the moon, mercury has cratered highlands and smoother lowlands, crater abundance is less than that of the moon, intercrater plains are the the oldest terrains. The calorie basin: <1/3 of it images by mariner 10, diamater: 1,550 km, age: 3. 85 ga (similar to imbrium and orientale basins on the moon) 2/20/17: lies 180 degrees to caloris, earlier features are heavily fractured, uniques in solar system, produced by focused seismic waves from caloris impact.