It made headlines on
Thursday, when reports said that there's a chance it could strike our
planet in less than 20 years. Such a collision could unleash a force as
powerful as a couple of thousand atomic bombs.
But NASA was quick to
calm nerves and point out some very good news. The most dangerous known
asteroids don't really pose much of a threat. And there are very few of
them.
Also, the chances that this one, which the Ukrainian astronomers who discovered it named 2013 TV135, will collide with Earth are extremely slim, NASA said in a statement it called "a reality check."
The space agency is 99.998% certain that when it whooshes back around the planet in 2032, it will simply sail past us again.
The probability of it
striking Earth currently stands at 1:63,000, and even those odds are
fading fast, as scientists find out more about the asteroid.
"This is a relatively new
discovery," said Don Yeomans, manager of NASA's NEO Program. "With more
observations, I fully expect we will be able to significantly reduce,
or rule out entirely, any impact probability for the foreseeable
future."
2013 TV135 was discovered
on October 8, while NASA was closed during the government shutdown. And
already it looks to soon be joining the ranks of the more than 10,000
known near-Earth objects that are virtually certain to cause us no harm.
But until then, it has the distinction of having a danger rating of 1 out of a possible 10 on the Torino Impact Hazard Scale, the system that gauges the danger of impact destruction by asteroids.
The 1 rating means that it poses "no unusual level of danger." There is "no cause for public attention or concern."
Almost all other
asteroids that scientists have discovered rank a 0 on the scale. There
is another asteroid with a danger rating of 1. And it, too, is no cause
for alarm, NASA says.
September's close pass
The close pass 2013
TV135 made on September 16 was not a near miss. At a distance of 4.2
million miles as it flew by, it was more than 15 times as far away from
Earth as the moon.
That pales by compare to the closest shave the Earth got from an asteroid of considerable size in recorded history.
On February 15 this
year, asteroid 2012 DA14, which measured 150 feet wide, slipped in below
the moon's orbit and squeaked by our planet just 17,200 miles from its
surface.
The one that passed by
in September is big, with a diameter of 1,300 feet. That's the size of
four football fields, but it does not quite make it an Earth crusher.
An asteroid needs to be at least twice as large to advance into that league.
"We believe anything
larger than one to two kilometers (about 0.6 to 1.2 miles) could have
worldwide effects," NASA said in a statement.
Russian divers find huge suspected meteorite chunk
Near passes daily
Two behemoths in that
size range will pass by planet Earth in the next three months at similar
distances as 2013 TV135. NASA says that neither will hit us.
Near asteroid passes are common. They pretty much occur daily, if not two or three times a day, NASA says.
They come, and they go, and they leave the Earth in peace.
In addition, particles from space bombard our planet every minute -- at a rate of 100 tons a day, NASA says.
You eat them; you drink them; you breathe them. Much of you and everything else on Earth contains them.
Distant catastrophe
Though it seems Earth is safe for now, there is such a thing as a doomsday asteroid.
Scientists say it is
likely that the impact of an asteroid over six miles wide wiped out
dinosaurs along with much of the life on Earth 65 million years ago.
More like it will come, NASA says.
But they only turn up once every "few million years."
That may give humanity some time to find a way of dealing with it.
SOURCE; CNN.COM
No comments:
Post a Comment