The Spirit rover on Mars has taken the first picture of Earth ever made from the surface of another planet, NASA scientists said Thursday.
The photo of Earth shows the planet as a bright dot above the horizon of Mars about an hour before sunrise, according to Mark Lemmon, a rover scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.
Lemmon said the image is not in color, but if a human stood in the same spot and looked earthward, home would probably appear pale blue.
Another sky photo from Spirit shows a thin and short streak of light.
"That streak could have been a meteor," Lemmon said. Or it could have been the Viking Orbiter 2, still circling Mars long after its 1970s mission ended.
The rover also took images in the direction of the constellation Orion. At least four bright stars are shown on these pictures.
None of Spirit's astronomy images are part of the rover's primary mission, Lemmon said. But by taking those pictures, scientists hope to learn something about the amount of dust and water vapor in the nighttime atmosphere of Mars.
On the other side of the planet, Opportunity captured animated images of Mars' moon Phobos eclipsing the sun. This, along with the previous image of Deimos' solar eclipse, will help astronomers map the small moons' orbits around the planet.
Knowing the moons' exact orbital path would allow satellites orbiting Mars to obtain close-up photos of the moon. Researchers do not know if the moons formed along with Mars or are captured asteroids.