PureInsight | March 3, 2003
[PureInsight.org] The first object other than Venus or Mercury to circle the Sun entirely inside Earth's solar orbit has been discovered. The asteroid may be one of many that inhabit that difficult-to-examine region of space.
The discovery was announced on February 13th in an electronic circular put out by the Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, MA.
Most asteroids -- many millions of them -- travel in a belt between Mars and Jupiter. Hundreds have been found wandering through the inner solar system, but until now all were on elongated orbits that took them back out at least beyond the orbit of Earth.
The newfound object is named 2003 CP20. Based on its brightness, it is estimated to be more than 0.6 miles wide (1 km). This is the minimum threshold for space rocks that might cause global destruction were one to hit Earth, experts say. But astronomers said this one poses no danger because of its orbit. Current estimates indicate that, at its closest, it will be some 17.7 million miles away.
The discovery was made by the Lincoln Near Earth Asteroid Research (LINEAR) project at MIT. Like most asteroids and even planets, 2003 CP20 does not carve a perfectly circular orbit. Officials at the center said the asteroid's greatest distance from the Sun, though, is less than the Earth's closest distance. The asteroid's trajectory is highly inclined, going above and below the imaginary plane in space through which Earth moves around the Sun. The asteroid is too far away and too dim to be seen from Earth without the use of good-sized telescopes.
Reference: http://www.space.com/scienceastronomy/asteroid_inside_030214.html
The Chinese version is available at http://www.zhengjian.org/zj/articles/2003/2/16/20479.html
