This is Methone, one of Saturn’s moons, as shown in Astronomy Picture of the Day 6/11/12.

What makes it strange is its apparent smoothness. Most celestial bodies in the Solar System outwith the gas giants and the Sun – including Earth – are cratered. Not only is Methone’s unpock-marked surface unusual, its egg-like shape is puzzling. As a rule small celestial objects are irregular in shape.