The Largest Rock in the Solar System
Credit: Voyager 1, NASA

Explanation: There, that faint dot in the center - that's the largest rock known in our Solar System. It is larger than every known asteroid, moon, and comet nucleus. It is larger than any other local rocky planet. (Nobody knows for sure what size rocks lie at the cores of Jovian planets, or orbit other stars.) It used to be the largest rock of any type known until earlier last year. The Voyager 1 spacecraft took the above picture of the giant space rock in 1990 from the outer Solar System. This rock is so large its gravity makes it nearly spherical, and holds heavy gases near its surface. Today, this rock starts another orbit around its parent star, for roughly the 5 billionth time, spinning over 350 times during each trip. Happy Gregorian Calendar New Year to all the human inhabitants of this rock we call Earth.

This is the broadest view of Earth that an astronaut can get from the International Space Station. Ed took this view of the ?Big Blue Beach Ball? using a wide angle lens while the Station was over the Pacific Ocean. In the foreground are the atolls of Tabitueua and Onotoa. ISS007-E-7304 (June 13, 2003, 16 mm lens). Image courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center.