NASA Says Comet Elenin Gone and Should Be Forgotten

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

Feature: 2011-331 Oct. 25, 2011

NASA Says Comet Elenin Gone and Should Be Forgotten

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2011-331&cid=release_2011-331

Comet Elenin is no more.

Latest indications are this relatively small comet has broken into even smaller, even less
significant, chunks of dust and ice. This trail of piffling particles will remain on the same path as
the original comet, completing its unexceptional swing through the inner solar system this fall.

"Elenin did as new comets passing close by the sun do about two percent of the time: It broke
apart," said Don Yeomans of NASA's Near-Earth Object Program Office in Pasadena, Calif.
"Elenin's remnants will also act as other broken-up comets act. They will trail along in a debris
cloud that will follow a well-understood path out of the inner solar system. After that, we won't
see the scraps of comet Elenin around these parts for almost 12 millennia."

Twelve millennia may be a long time to Earthlings, but for those frozen inhabitants of the outer
solar system who make this commute, a dozen millennia give or take is a walk in the celestial
park. Comet Elenin came as close as 45 million miles (72 million kilometers) to the sun, but it
arrived from the outer solar system's Oort Cloud, which is so far away its outer edge is about a
third of the way to the nearest star other than our sun.

For those broken up over the breakup of what was formerly about 1.2 miles (two kilometers) of
uninspiring dust and ice, remember what Yeomans said about comets coming close to the sun –
they fall apart about two percent of the time.

"Comets are made up of ice, rock, dust and organic compounds and can be several miles in
diameter, but they are fragile and loosely held together like dust balls," said Yeomans. "So it
doesn't take much to get a comet to disintegrate, and with comets, once they break up, there is no
hope of reconciliation."

Comet Elenin first came to light last December, when sunlight reflecting off the small comet was
detected by Russian astronomer Leonid Elenin of Lyubertsy, Russia. Also known by its
astronomical name, C/2010 X1, Elenin somehow quickly became something of a "cause célèbre"
for a few Internet bloggers, who proclaimed this minor comet could/would/should be responsible
for causing any number of disasters to befall our planet.

Internet posts began appearing, many with nebulous, hearsay observations and speculations
about earthquakes and other disasters being due to Elenin's gravitational effects upon Earth.
NASA's response to (http://www.jpl.nasa.gov/news/news.cfm?release=2011-255) such wild
speculations was then in turn speculated to be an attempt to hide the truth.

"I cannot begin to guess why this little comet became such a big Internet sensation," said
Yeomans. "The scientific reality is this modest-sized icy dirtball's influence upon our planet is so
incredibly miniscule that my subcompact automobile exerts a greater gravitational influence on
Earth than the comet ever would. That includes the date it came closest to Earth (Oct. 16), when
the comet's remnants got no closer than about 22 million miles (35.4 million kilometers)."

Yeomans knows that while Elenin may be gone, there will always be Internet rumors that will
attempt to conjure up some form of interplanetary bogeyman out of Elenin, or some equally
obscure and scientifically uninteresting near-Earth object. Thinking of ways to make himself
any more clear about the insignificance of this matter is somewhat challenging for a scientist
who has dedicated his life to observing asteroids and comets and discovering their true nature
and effects on our solar system.

"Perhaps a little homage to a classic Monty Python dead parrot sketch is in order," said
Yeomans. "Comet Elenin has rung down the curtain and joined the choir invisible. This is an ex-
comet."

NASA detects, tracks and characterizes asteroids and comets passing relatively close to Earth
using both ground- and space-based telescopes. The Near-Earth Object Observations Program,
commonly called "Spaceguard," discovers these objects, characterizes the physical nature of a
subset of them, and predicts their paths to determine if any could be potentially hazardous to our
planet. There are no known credible threats to date.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in
Washington. JPL is a division of the California Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at:
http://www.jpl.nasa.gov/asteroidwatch , and on Twitter: @asteroidwatch .

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=mgIRIYOxFdJUJcL&s=kuK2K7PNIgLOJ6MTLuG&m=frKWJ8MLLjKTKeI

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=rlL1LdMRLjKWLiI&s=kuK2K7PNIgLOJ6MTLuG&m=frKWJ8MLLjKTKeI