On its 449th martian day, or sol (April 29, 2005), NASA's Mars rover
Opportunity woke up approximately an hour after sunset and took this
picture of the fading twilight as the stars began to come out. Set against
the fading red glow of the sky, the pale dot near the center of the
picture is not a star, but a planet -- Earth.
Earth appears elongated because it moved slightly during the 15-second
exposures. The faintly blue light from the Earth combines with the
reddish sky glow to give the pale white appearance.
The images were taken with Opportunity's panoramic camera, using
440-nanometer, 530-nanometer, and 750-nanometer color filters. In
processing on the ground, the images were shifted slightly to compensate
for Earth's motion between one image and the next.
