April 17, 2002: The Hubble Space Telescope is hot on the trail of a puzzling new class of solar system object that might be called a Pluto "mini-me." Together, these objects are 5,000 times less massive than Pluto and Charon. Like Pluto and Charon, these dim and fleeting objects travel in pairs in the frigid, mysterious outer realm of the solar system called the Kuiper Belt, a long-hypothesized "junkyard" of countless icy bodies left over from the solar system's formation. A total of seven binary Kuiper Belt objects have been seen so far by Hubble and ground-based observatories. Among them is a pair called 1998 WW31, which the Hubble telescope studied in detail.See the rest:
It is difficult to determine how Kuiper Belt objects wind up traveling in pairs. The couples may have formed that way, born like twins, or may be produced by collisions, where a single body is split in two.
More than one percent of the 500 known Kuiper Belt objects are double systems. Many astronomers think that studying binary Kuiper Belt objects will be a very exciting and rapidly evolving field of research in the coming years.
The Kuiper Belt is one of the last big missing puzzle pieces in understanding the origin and evolution of our solar system and planetary systems around other stars. Dust disks seen around stars are no doubt replenished by collisions among Kuiper Belt objects. These objects may offer fundamental clues to the birth of planetary systems.
Credit: NASA and C. Veillet (Canada-France-Hawaii Telescope)