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Spitzer Space Telescope set its infrared eyes upon the dusty remains of shredded asteroids around several dead stars. This artist's concept illustrates one such white dwarf, surrounded by the debris of a disintegrating asteroid. These observations help astronomers better understand what rocky planets are made of around other stars.

Asteroids are leftover scraps of planetary material. They form early in a star's history when planets are forming out of collisions between rocky bodies. When a star like our sun dies, shrinking down to a white dwarf, its asteroids get jostled about. If one of these asteroids gets too close to the white dwarf, the stars gravity will chew up the asteroid, leaving a cloud of dust.

Spitzer's infrared detectors can see these dusty clouds and their various constituents. So far, the telescope has identified silicate minerals in the clouds polluting eight white dwarfs. Because silicates are common in our Earth's crust, the results suggest that planets similar to ours might be common around other stars.

Image Credit: NASA/JPL-Caltech