Larissa

A mid-sized inner moon of Neptune with an irregular shape and heavily cratered surface, discovered in 1981 by Harold Reitsema using ground-based stellar occultation observations.

A space probe launched in 2005 that successfully collided its impactor with comet Tempel 1 at 23,000 mph, creating a crater and revealing the comet's internal composition while the main spacecraft observed and analyzed the impact debris.

Callisto

The second-largest of Jupiter's Galilean moons and the third-largest moon in the Solar System, heavily cratered Callisto appears ancient and inactive with a dark, icy surface that has remained largely unchanged for billions of years.