By Ron Cowen
A flying observatory has taken the first ultrasharp images of rings of cold debris around sunlike stars. The doughnut-shaped rings appear to be extrasolar analogues of the Kuiper belt, the outer solar system’s reservoir of comets and other frozen bodies.
The newly observed rings are either left over from the planet-making process or were generated when planets collided. Astronomers used the European Space Agency’s infrared Herschel Space Observatory, which sports the largest light-collecting mirror in space and is exquisitely sensitive to cold, sand-grain-sized dust, to photograph the belts.
”The Herschel images are the highest resolution far-infrared measurements ever made for debris disks” like the Kuiper belt, says infrared astronomer George Rieke of the University of Arizona in Tucson, who was not involved in the study.