That’s not a giant bath bomb, it’s our Moon! We usually see Earth’s Moon in shades of gray, but here in this composite photo made from images captured by our Galileo spacecraft, it’s a riot of reds, oranges, and blues. And sure, it’s pretty, but that’s not the (only) reason we color images. The unusual colors in this photograph help scientists study what the Moon’s soil is made of. Areas appearing red generally correspond to the lunar highlands, while blue to orange shades indicate the ancient volcanic lava flow of a mare, or lunar sea. Bluer mare areas contain more titanium than the orange regions do. The deep blue patch on the right is Mare Tranquillitatis, and it’s richer in titanium than Mare Serenitatis, a slightly smaller circular area to the upper left of Mare Tranquillitatis. Finally, the small purple areas found near the center are deposits formed by explosive volcanic eruptions. The solid-state imaging system on Galileo captured 15 images of the Moon through three color fi...