Sunlight Spawns Binary Asteroids (Image 1)

An artist's rendering of an asteroid pair during its short-lived, proto-binary phase, that may last less than 1 million years. In these unstable proto-binary systems, the primary typically has a diameter of a few kilometers, while the companion is 60 percent or less the size of the primary. Shortly after its formation, the secondary will gently escape, resulting in two asteroids that share the same orbit around the sun. Credit: ESO/L. Calcada