Planet Collision
January 6, 2010—Two large, rocky bodies collide while in orbit around the star HD 131488 in an artist's conception. Such a collision would explain a ring of warm dust recently found inside the star's terrestrial planet zone, the region in which the star would heat matter to temperatures like those on Earth.
Astronomers using the Gemini South telescope in Chile found that the dust in this warm ring is completely alien—it's unlike any dust yet seen around another star. In addition, HD 131488 hosts a ring of cold dust at a similar distance as the Kuiper belt is from our sun. This cooler dust is most likely left over from planets that formed farther from the star, scientists suspect.
SPACE PHOTOS THIS WEEK: Alien Dust, Zodiac Light, More
A rocky collision churns up unusual dust, zodiacal light appears over Chile, a spring thaw sends sand cascading down Martian dunes, and more in our selection of the week's best space pictures.