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.
Here’s a cool time-lapse movie of the Earth as seen from Mercury-bound Messenger during it’s recent gravity assist swing-by.
Mercury is Messenger’s destination mostly because NASA needed a foreign point to fly to in order to show us that the earth is, in fact, round.
I think I saw my house!
Comprising 358 frames taken over 24 hours, the movie follows Earth through one complete rotation. The spacecraft was 40,761 miles (65,598 kilometers) above South America when the camera started rolling on Aug. 2. It was 270,847 miles (435,885 kilometers) away from Earth – farther than the Moon’s orbit – when it snapped the last image on Aug. 3.
Messenger will approach the planet in early 2011 and proceed to make 3 flybys. These flybys will allow refined experiments to be designed and implemented, as it were, on the fly. It will settle in to Mercury’s orbit and carry out extensive measurements for one full Earth year.