Saturn’s moons Mimas and Pandora are the subject of a beautiful new image taken by NASA’s Cassini spacecraft. The photo was taken by Cassini’s narrow-angle camera on May 14, 2013.
Seeing the two moons together in one image makes for an interesting sight, owing to their differences — Pandora is a relatively small moon (50 miles across) that didn’t possess the mass necessary to pull itself into a round shape in the same way that the larger moon Mimas did. It’s thought — by researchers — that the strange elongated shape of Pandora may hold clues to how it, and the other moons near Saturn’s rings, formed.
NASA has more: “This view looks toward the anti-Saturn hemisphere of Mimas (246 miles, or 396 kilometers across). North on Mimas is up and rotated 28 degrees to the right. The image was . The view was acquired at a distance of approximately 690,000 miles (1.1 million kilometers) from Mimas. Image scale is 4 miles (7 kilometers) per pixel. Pandora was at a distance of 731,000 miles (1.2 million kilometers) when this image was taken. Image scale on Pandora is 4 miles (7 kilometers) per pixel.”
“The surface area of Mimas is slightly less than the land area of Spain. The low density of Mimas, 1.15 g/cm³, indicates that it is composed mostly of water ice with only a small amount of rock. Due to the tidal forces acting on it, Mimas is noticeably prolate; its longest axis is about 10% longer than the shortest. The ellipsoidal shape of Mimas is especially noticeable in some recent images from the Cassini probe.”
“From its very low density and relatively high albedo, it seems likely that Pandora is a very porous icy body. There is a lot of uncertainty in these values, however, so this remains to be confirmed.”