Please let me know if you want ON or OFF my ping list!. . .don't be shy.
Posted on 06/21/2002 5:16:28 AM PDT by Cincinatus' Wife
WASHINGTON (Reuters) - An asteroid the size of a soccer field whizzed by Earth at a distance much nearer than the Moon, the biggest such space rock in decades to get this close, scientists said on Thursday.
Asteroid 2002MN was not detected until Monday, three days after its closest approach on June 14, when it got within 75,000 miles of Earth and was traveling at a speed of some 23,000 miles per hour, astronomers said.
It is now several million miles away, according to Brian Marsden of the Harvard-Smithsonian Center for Astrophysics' Minor Planet Center, which tracks asteroids.
"It's the largest (asteroid) we've seen at that distance in the last several decades," Marsden said in a telephone interview.
The last time any asteroid came this close was in 1994, according to the Near Earth Object Information Center in Britain.
The big rock, with a diameter of roughly 50 yards to 120 yards, would not have caused global catastrophe if it had struck Earth. That would take an asteroid of several miles diameter.
However, if it had hit Earth, it had the potential to cause as much local devastation as a 1908 hit in Tunguska, Siberia, which flattened some 800 square miles of forest.
Asteroid 2002MN was first spotted by the Lincoln Near Earth Asteroid Research program, based in Socorro, New Mexico.
"It's a good thing it missed the Earth, because we never saw it coming," Steve Maran of the American Astronomical Society said in a telephone interview. "The asteroid wasn't discovered until three days after it passed its closest approach to our planet."
LINEAR is part of the National Aeronautics and Space Administration's initiative to find 90 percent of all near-Earth objects, including asteroids, that measure .62 mile or more in diameter by 2008.
An asteroid the size of 2002MN may hit Earth about once every hundred years or so, and the planet may not have seen the last of this one, Marsden said.
"There is a slim chance it could hit in 2061," he said, putting that chance at about one in 100,000.
"At some level, it behooves us to look out for these things," he said.
Asteroid 2002 MN will be observable by some telescopes but it is getting fainter as it moves away, Marsden said.
Imagine, we didn't even know it had happened until three days after the close encounter!
Once they hit the atmosphere they detonate above ground and flatten what's below.
It's the big boys, thousands of miles in diameter that can snuff out human life on earth.
As of now, we have nothing to stop or deflect these monsters in space.
Food for thought.
I'm certainly no astrophysicist, but astronomy, along with cosmology and quantum physics, have long been a hobby of mine.
Generally speaking, anything with the velocity of a typical asteroid will blaze by an object the size of the earth in a matter of about fifteen to twenty minutes or so. Add to that the mass of such an object, which adds to it's momentum, and chances are rather slim. This rapidly changes if the object is close enough to interact with the Earth's atmosphere, which then imparts enormous drag and friction, and dramatically decreases the object's kenetic energy (not to mention creates quite a show).
Bottom line, unless something like this is coming straight at us to start with, chances of the Earth "snagging" it are slim. Gravity is a terrifically weak force, although, since it is only accumlative (unlike the other three fundamental forces of nature), it overall is the most pervasive and influential.
I wouldn't want to be under it when it exploded in the atmosphere..
It wouldn't take anything nearly that large to wipe-out most of the life on the planet. It's believed that the asteroid that killed the dinosaurs (among other things) was about 5 miles in size, impacting and creating what is now the Gulf of Mexico.
Another variable is the makeup of the object. If it's mostly ice (like a small comet) there would be less damage. But if it was comprised of iron, nickle or just plain old rock, then we would have an extinction level event on our hands.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.