There is space stuff crashing into the Earth all the time,
which is not a problem as long as it’s small stuff.
Big objects, like the asteroid 2011 AG5, are more of a
problem. Big objects can create big craters, can throw immense amounts of
material into the atmosphere, which can block the sun, and change the climate,
and cause mass extinctions.
(Image: Asteroid 2011 AG5, as viewed by the Gemini
Multi-Object. Credit: UH IfA, Gemini Observatory.)
But 2011 AG5 won’t be one of those big objects, according to
new research from the University of Hawai`i’s Institute for Astronomy and the
Gemini North telescope on Mauna Kea. It will come close, but will miss the
planet by about a half million miles, they said.
Earlier research had estimated that there was a small chance—1
in 500—that 2011 AG5 could hit the planet, on Feb. 5, 2040. And since it’s a
big one—a couple of football fields across—that could be a big problem, they
said.
“If this object were to collide with the Earth it would have
released about 100 megatons of energy, several thousand times more powerful
than the atomic bombs that ended World-War II. Statistically, a body of this
size could impact the Earth on average every 10,000 years,” says the Institute
for Astronomy release on the subject.
The Gemini’s Multi-Object Specrograph snagged views of the
asteroid low in the sky in late October. The University of Hawai`i’s 2.2 meter
telescope on Mauna Kea spotted the asteroid two weeks earlier. From those
views, researchers were able to refine its orbit.
The calculations were initially made by Institute for
Astronomy researchers David Tholen, Richard Wainscoat, Marco Micheli, and
Garrett Elliott, with further analysis by NASA’s Near-Earth Object Program
Office at California’s Jet Propulsion Laboratory.
NASA reported that based on their work, the possibility of
an impact has been eliminated.
© Jan TenBruggencate 2012
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