The solar system got a little bigger last year. The discovery of the distant object 1992 in an orbit beyond Pluto extended the dimensions of the planetary system and provided important evidence for several hypotheses about the origin of the solar system and the source of short-period comets.
The new object was found by David Jewitt of the University of Hawaii and Jane Luu of the University of California, Berkeley, who had spent more than 5 years in the search. On August 30, using the 2.2-m University of Hawaii telescope on Mauna Kea, they detected a slow-moving, 23rd magnitude object in Pisces. The initial observations suggested a distance of 41 AU. At that distance, if one assumed a typical comet nucleus albedo of 0.04, the object would have to be about 200 km in diameter [Jewitt and Luu, 1992].