[meteorite-list] Screwy asteroids

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Tue Jun 13 12:23:16 2006
Message-ID: <m9js8218bn2241ajsf2ic0r7pi589tg4g4_at_4ax.com>

http://www.msnbc.msn.com/id/13251064/

Corkscrewing asteroid leaves Earth behind
Orbital oddity gets a push into deep space from our planet
Space.com


Updated: 12:56 a.m. ET June 11, 2006
An asteroid that has been corkscrewing around Earth in recent years is now
heading for deep space, according to NASA.

The object, named 2003 YN107, was discovered in 2003. It arrived in Earth's
vicinity in 1999, scientists have calculated. "It's been corkscrewing around
Earth ever since." said Paul Chodas of NASA's Near Earth Object Program at the
Jet Propulsion Laboratory.

The rock is relatively small and is not a threat to hit the planet.

Most space rocks that approach Earth fly on by.

"We believe 2003 YN107 is one of a whole population of near-Earth asteroids that
don't just fly by Earth," Chodas said. "They pause and corkscrew in our vicinity
for years before moving along."

These asteroids are called Earth co-orbital asteroids or "co-orbitals." They
share Earth's orbit, circling the sun in almost exactly a year. They can catch
up to Earth from behind, or Earth can catch them.

"These asteroids are not truly captured by Earth's gravity," Chodas said in a
NASA statement issued this week. "But from our point of view, it looks like we
have a new moon."

At least four small asteroids behave similarly: and 2001 GO2, 2002 AA29, 2004
GU9 and 2003 YN107. More likely exist but await discovery by improved search
technology.

And an object known as Cruithne has been trapped in a suspended state around
Earth for at least 5,000 years.

The corkscrew path of 2003 YN107 is lopsided, and on Saturday it dipped within
2.1 million miles (3.4 million kilometers) of Earth, slightly closer than usual,
according to NASA. Earth's real moon is 238,900 miles (384,472) miles away.

Earth's gravity then gave the asteroid a nudge to send it on its way.

In about 60 years, 2003 YN107 will lap Earth again, resuming its role as a
temporary, corkscrewing moonlet.

? 2006 Space.com. All rights reserved. More from Space.com.
Received on Tue 13 Jun 2006 01:31:56 AM PDT