Earth and Moon from Mars Surveyor
May 30, 2003
On May 8, 2003, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took a break from observing the Red Planet to see just what our planet looked like from about 139 million kilometers (86 million miles) away. This is the first image of Earth ever taken from another planet that actually shows our home planet as a disk. Earth and Moon are seen here from the evening sky of Mars.
Because Earth and the Moon are closer to the Sun than Mars, they exhibit phases, just as the Moon, Venus, and Mercury do when viewed from Earth -- Earth is half-illuminated here (quarter phase). The MOC Earth/Moon image has been specially processed to allow both Earth (with an apparent magnitude of -2.5) and the much darker Moon (with an apparent magnitude of +0.9) to be visible together. The bright area at the top of the image of Earth is cloud cover over central and eastern North America, and the shiny feature near the center-right of the crescent Earth is a cloud system over northern South America. The image also shows the Earth-facing hemisphere of the Moon, since the Moon was on the far side of Earth as viewed from Mars. The slightly lighter tone of the lower portion of the image of the Moon results from the large and conspicuous ray system associated with the crater Tycho.