This recently uncovered Solar System mystery is currently a topic of research, however.
The unexpected finding originated last October when the robot Cassini spacecraft, currently orbiting Saturn, swooped past the 24-kilometer moon and captured the first ever image of Telesto's surface.
Pictured above, Telesto's unusually smooth surface was found to show some large craters and boulders, but not the high density of craters found on nearby Tethys or most other Saturnian moons.