NASA's Hubble Space Telescope reveals the dusty aftermath of the violent birth of alien planets, seen in this view of the debris cloud surrounding a star.
Astronomers think these clouds form when asteroids, comets, and mini-worlds collide, leftover from eras of planet formation. To their surprise, this blue-eyed disc of dust is far from featureless, revealing regularly spaced spokes, ripples, and divots. The structure and complexity revealed by Hubble's observations hint at hidden forces shaping the disk. (See "Stunning Snapshot Shows Birth of Alien Solar System.")
Researchers speculate that hidden exoplanets orbiting the star might tug on the disk, sculpting its shape. Another possibility is that the debris field shifts as its star travels through interstellar space. (See "Three Theories of Planet Formation Busted, Expert Says.")
—By Jane J. Lee, photo gallery by Sherry L. Brukbacher
Week's Best Space Pictures: Rover Drills, Stars Collide, and a Rocket Launches
Curiosity drills Mars for rocky reassurance, some stars throw tantrums as they collide, and a rocket launches to study the sun.