The Year in Science: Astronomy 1997

Astronomers Jane Luu of Harvard and David Jewitt of the University of Hawaii in Honolulu have discovered dozens of icy worlds on the edge of the solar system, but none as strange—or as bright—as the one they unveiled last June. In fact, their new find, called 1996TL66, is most likely the first of an entirely new class of objects in the solar system. With an estimated diameter of more than 300 miles, 1996TL66 is neither an ordinary planet nor a moon—its crazy, 780-year orbit being more like that of a comet. From a point near the orbit of Neptune, where Luu and Jewitt found it, it swings out to a distance more than four times that of Neptune from the sun and more than 130 times that of Earth from the sun, all while tilted at an angle of 24 degrees from the plane of the solar system. No one is entirely sure how this miniplanet got there, but Luu guesses there are as many as 6,000 others waiting to be discovered. We didn’t have to cover the entire sky to find this, she says. We found it relatively easily, so unless we were incredibly lucky, there should be many others like it.