Fading reddish Sky, shining Blue Planet!

Caption NASA originale:"On its 449th Sol (April 29, 2005), NASA's MER 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" 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 PanCam, using 440, 530 and 750-nnmts color filters. In processing on the ground, the images were shifted slightly to compensate for Earth's motion between one image and the next".