A strange object that moves like a comet but looks like an asteroid was spotted in space by an Air Force telescope using a special camera.
The object, with a diameter of 5 to 10 miles, may be an unusual asteroid or a dead comet stripped of all volatile material, NASA officials said Wednesday."This is a misfit in the grand scheme of things," Eleanor Helin, principal investigator of the Near-Earth Asteroid Tracking program at NASA's Jet Propulsion Laboratory, said in a statement. Scientists said nothing like it has been seen before.
The object, dubbed 1996 PW, was spotted in data taken from an Aug. 9 observation atop Mount Haleakala on Maui, Hawaii. A special camera attached to the telescope automatically surveys the skies for objects - asteroids and comets - which could pose a hazard to Earth.
Asteroids are rocky bodies that mainly orbit in the "asteroid belt" between Jupiter and Mars. Comets generally have orbits that go beyond the planets and have volatile material streaming off.
No comet-like gas emissions were observed from 1996 PW, even during its closest approach to the sun, supporting the argument that the object is an asteroid.
However, its orbit is estimated to have a period of 5,000 years, an elongated, comet-like circuit that stretches into the void beyond the orbits of Neptune and Pluto.
The orbits of the majority of asteroids are on the order of three to five years, and in an extreme case, 50 years, said Steve Pravdo, project task manager for the asteroid tracking program.