In 2006, the Arecibo Observatory bounced radio waves off of the flying-saucer-shaped asteroid 1999 KW4 (top) and its moon (bottom), creating the best 'pictures' of an asteroid pair ever made.
Illustration: Kevin Walsh/Derek Charles Richardson/UMD
Pairs of asteroids can be created from a single parent body that spins so fast due to solar energy that it breaks apart. In new computer simulations, the parent body was modelled as a rubble pile. Loose material near its poles rolled to its equator, then floated off to become a moon.
PlanetBye is a blog run by Bente Lilja Bye aka Stellare. PlanetBye covers mainly scientific topics but also completely random topics like art, social media, personal ramblings etc. The posts on this blog are generally short with links to further reading and sources of information. Clicking on images is encouraged.