On the heels of the return to Earth of a pair of satellites — NASA’s
Upper Atmosphere Research Satellite (UARS) and the German-built
Röntgensatellit (ROSAT) — over the past two months comes a report of
another object set to collide with our planet.
Only this one is a 20 million ton asteroid that is currently heading
towards us at 23,000 miles per hour, and could collide with our planet
in approximately 25 years, Alex Hannaford of the Telegraph wrote on
Sunday. The asteroid in question, Apophis, is more than 800 feet wide,
comprised of a mixture of rock, ice, and dust, and has been dubbed “the
continent killer.”
“There are two scenarios,” Hannaford writes. “The first, and
thankfully most likely, is that Apophis will fly by in April 2029, the
year it is due to make its first ‘close approach’, and that’s the last
we’ll see or hear of it. The second is that during that approach, it’ll
pass through what scientists refer to as a ‘keyhole’ — a small area of
space that can alter the asteroid’s course due to Earth’s gravity.”
“If this happens, it’ll be on a massive collision course with us
seven years later, likely to be April 13, 2036 — Easter Sunday,” the
Telegraph reported added, noting that experts with NASA’s Jet Propulsion
Laboratory in California claim that it is “too far away” to predict
which of the two possibilities is most likely, but that they should be
able to know more in the near future.
“We don’t know precisely where Apophis is headed but we will soon,
when it becomes observable again, probably in 2012 or 2013,” Paul Chodas
of the U.S. space agency’s Near Earth Object (NEO) said. “Once we get
radar on it we will be able to nail down its orbit and we will know the
chances of it going through the keyhole and hitting in 2036. By that
time, it could be a four in a million chance, and that could very well
go down to zero.”
That might not be the end of it, though, as Chodas told Hannaford
that the asteroid could find another one of those “keyholes” — small
regions of space that can alter the course of a passing asteroid, due to
a planet’s gravity — meaning that even if it misses the planet the
first time, it could theoretically return and collide with the Earth’s
surface later on.
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