Astronomers provided the best evidence yet for an asteroid belt beyond the solar system; new measurements located the disk of warm dust surrounding the star Zeta Leporis, at just 70-light years away.

This dust lies at about the same distance from Zeta Leporis as the solar system's asteroid belt lies from the sun.

Most previously observed disks have been cool and lie much farther from their parent stars, in the region that corresponds in the solar system to the locale of Pluto and the reservoir of comets known as the Kuiper belt.

"The close-in dust around Zeta Leporis probably arose when several asteroids bumped into each other, grinding rock into a fine spray of particles, or when a large asteroid, perhaps 100 kilometers in diameter, suffered a cataclysmic wallop," said Margaret M. Moerchen and Charles M. Telesco, also from the University of Florida in Gainesville.

"The [precise] measurement of the Zeta Leporis disk is a very exciting result," says Charles Beichman of NASA's Jet Propulsion Laboratory in Pasadena, California.

"We now have direct evidence for structures around other stars that are directly analogous to the asteroid belt in our solar system."

"Additionally, research finds that the location of the dust is at a distance of 3 astronomical units (AU) from Zeta Leporis, quite similar to the location of the solar system's asteroid belt, stretching from 2.1 to 3.3 AU from the sun," said Ron Cowen.

Because asteroids are leftovers from the planet-making process in the solar system, the new study "supports the thought that Earthlike planets may exist" outside the solar system, said Michael Jura of the University of California, Los Angeles who observed the dust in the disk surrounding Zeta Leporis to find its radius.

"The team is planning further observations to reveal the Zeta Leporis disk's shape. If it's circular and uniform in density, the disk probably formed by the slow grinding of asteroids over thousands of years. A more distorted shape would suggest that the dust was generated by a collision between two large chunks of rock only about 100 years ago," Telesco says.

"For years we've been studying Kuiper belt-like disks; now, we're investigating the architecture of the inner asteroidal regions" around stars.

"This is kind of new territory," Telesco says.

Further research will attempt to reveal the shape of the Zeta Leporis' disk as well as providing insight into its possible formation, continuing efforts to understand the inner territory of our skies.