MESSENGER: The Mission

MESSENGER is a scientific investigation of the planet Mercury, the least explored terrestrial planet. Understanding Mercury and how it was formed is essential to understanding the other terrestrial planets and their evolution. Mercury has been visited by only one other spacecraft, Mariner 10, so we know little more than its average density (the second greatest of all the planets), the composition of its atmosphere (thinnest of the terrestrial planets), the fact that it posses a global magnetic field, and its extreme variations in temperature. MESSENGER will serve to lift some of the uncertainty about this innermost planet of our solar system.

The MESSENGER mission will orbit Mercury after making three flybys of the planet, using data collected during the flybys as an initial guide to perform a more focused scientific investigation of this mysterious world. MESSENGER will investigate six key scientific questions about Mercury’s characteristics and environment with a set of miniaturized space instruments. The spacecraft will enter Mercury orbit in March 2011 and carry out comprehensive measurements for one full Earth year.