AS101 Lecture Notes - Lecture 4: Mariner 10, Plate Tectonics, Escape Velocity
Document Summary
Mercury has been visited by just two spacecraft (mariner 10 in 1974-5 and now. Messenger in 2011) allowing its mass and density to be accurately determined (recall that a planet"s mass can only be determined by using newton"s form of. Kepler"s law which requires information about a natural or artificial satellite"s orbital parameters) and to obtain views and measurements of surface features. As a result of these measurements it has been determined that mercury must be about 61% iron and have an iron core which is about 75% of the radius of the planet. Mariner 10"s orbit from earth in late 1973 (many of you were not yet born) included a flyby of venus (from which it got a gravitational boost) and three encounters with mercury over a twelve month period. Mercury"s surface has craters everywhere (much like the moon) revealing a battered past (in the formation era).
