From Mercury orbit, MESSENGER watches a lunar eclipse
Posted by Emily Lakdawalla
10-10-2014 10:07 CDT
I don't believe I've ever seen anything like this before. We've watched our Moon pass into Earth's shadow from Earth's surface, Earth orbit, and lunar orbit, but from Mercury orbit? Just watch as our enormous moon -- a quarter the diameter of the planet -- just winks out as it passes into Earth's long shadow.
A little more information about the observation, from the MESSENGER website:
MESSENGER was 107 million kilometers (66 million miles) from the Earth at the time of the lunar eclipse. The Earth is about five pixels across, and the Moon is just over one pixel across in the field of view of the spacecraft's narrow-angle camera, with about 40 pixels distance between them. According to [planetary scientist Hari] Nair, the images are zoomed by a factor of two, and the Moon's brightness has been increased by a factor of about 25 to show its disappearance more clearly.
One of the best things about missions that have survived long past their initial warranty is that mission managers have the freedom to try creative and challenging observations with their spacecraft. Thank you, MESSENGER team, for this surprising home movie!
Only about five months remain in the MESSENGER mission before the spacecraft runs out of fuel and crashes into the planet. Its orbit is now extremely low at periapsis and evolves lower over time, so depends on occasional reboosts to keep it at altitude. The most recent orbit boost happened on September 24. Two more are planned, for October 24 and January 21.