By measuring tiny dips in the intensity of X rays from a distant star, astronomers say that they have detected more than 50 of the tiniest chunks of ice ever found in the outer solar system.
Since 1992, researchers have discovered nearly 1,000 frozen bodies beyond Pluto. All are at least several tens of kilometers in diameter. In contrast, the newfound objects are only 10 to 100 meters in diameter.
These small fry can't be seen with even the world's largest telescopes. Instead, a team led by Hsiang-Kuang Chang at the National Tsing Hua University in Hsinchu, Taiwan, used an indirect technique. The group looked for random, brief drops in brightness of the star Scorpius X-1, the brightest X-ray source in the sky.