The Earth and Moon as seen from Mars.

By Robert Roy Britt
Senior Science Writer

"A spacecraft orbiting Mars has turned its eye homeward to photograph Earth as its never been seen before, capturing a surprisingly detailed image of our blue world suspended in the vast black of space."

Unlike any previous image of Earth from another planet, clouds and continental features are visible.

Planet Earth is seen as a half-globe. The effect is the same as seeing phases of Venus from Earth. Like Earth's Moon, an inner planet reflects sunlight differently depending on its location in relation to the planet it is viewed from.