MESSENGER's Polar Orbit
This schematic of MESSENGER’s orbit illustrates some of the challenges to acquiring observations of Mercury’s north polar region. During its primary orbital mission, MESSENGER was in a 12-hour orbit and was at an altitude between 244 and 640 km at the northernmost point in its trajectory. Since April 2012, MESSENGER has been in an 8-hour orbit (shown here), and it has been at an altitude between 311 and 442 km at the northernmost point in its trajectory. Even from these high-latitude vantages, Mercury’s polar deposits fill only a small portion of the field of view of many of MESSENGER’s instruments.
Date acquired: November 29, 2012
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington