[meteorite-list] Discovery: Asteroid Found Roaming Within Earth's Solar Orbit
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:27 2004
Discovery: Asteroid Found Roaming Within Earth's Solar Orbit
By Robert Roy Britt
14 February 2003
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.
Most asteroids -- many millions of them -- travel in a belt between Mars
and Jupiter. Hundreds have been found wandering through the inner solar
system, however, 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.
The asteroid is too far away and too dim to be seen from Earth without
the use of good-sized telescopes.
It was discovered earlier this week by the Lincoln Near Earth Asteroid
Research (LINEAR) project at MIT. The asteroid hunting program is
funded by the U.S. Air Force and NASA. The discovery was announced
Thursday in an electronic circular put out by the Minor Planet Center
at the Smithsonian Astrophysical Observatory in Cambridge, MA.
Like most asteroids and even planets, this one 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.
Current estimates show that 2003 CP20 can't come closer to Earth than
17.7 million miles (28.4 million km). It will pass within 4.65 million
miles (7.48 million km) of Venus more than once, however. For
perspective, the Moon is about 238,900 miles (384,402 km) from Earth.
Spotting asteroids is tricky business. Last June, an asteroid passed
within 75,000 miles (119,229 kilometers) of Earth and was not spotted
until three days later.
Received on Fri 14 Feb 2003 12:41:04 PM PST