Posted on 06/17/2003 8:01:59 AM PDT by Mike Darancette
The headline read: "Massive tsunami sweeps Atlantic Coast in asteroid impact...." It was at that point that I wished that I had taken a speed-reading course, because the rest of the headline read: "...scenario for March 16, 2880."
I'm really thankful for all those folks who spend countless hours each week with their eyeballs glued to the small end of a telescope as they search the skies, keeping constant vigil for anything heading toward Earth that's larger than a frozen turkey. The men and women of NASA and the Jet Propulsion Lab, college professors and their student assistants and even the amateur astronomers are doing a commendable job of standing guard at Earth's edge, ready to climb the clock tower and ring the bell at the first sign of an outer space object that's threatening our world.
But that's only reassuring to a degree, because one must wonder: If some of the rocks spinning around in the asteroid belt should engage in a game of billiards next week and end up knocking an eight-ball earthward and the target was downtown Phoenix, would our celestial sentries have enough of an advance notice to dial up a few 602 numbers and advise Phoenicians to get out of town?
My question arises out of an incident that took place on March 8, 2002, when an asteroid the size of a Boeing 747 passenger jet slipped past all of the sky watchers, flew within 280,000 miles of planet Earth - just beyond where the moon hangs out - and was finally discovered a day later. Of even greater concern is the fact that three more days passed before the rest of the world was notified of the event.
With that amount of miles between Earth and asteroid 2002 EM7, most people would not consider that a close call, but in terms of the vastness of space, it was like getting brushed back by a Randy Johnson fastball.
According to Jeff Hecht, a journalist with New Scientist, EM7 was difficult to see because it was moving outward from the innermost point of its orbit approximately 50 million miles from the sun.
"When it passed closest to the Earth," Hecht wrote, "it was too close to the sun to be visible. Asteroids approaching from this blind spot would not be seen by astronomers. If a previously unknown object passed through this zone on a collision course with Earth, it would not be identified until it was too late for any intervention."
This revelation doesn't exactly have me reaching for a bottle of tranquilizers and a hard hat. On the other hand, I don't think that I'll be resting too comfortably in my recliner chair the next time an ultra-light aircraft buzzes my house, because despite all of the sophisticated glass pointing skyward and all of the incredible technology available to map and track a large variety of outer space objects, there is no question that the occasional maverick asteroid can slip through the fence and trample the grass in our front yards.
This takes me back to the UCSC press release. Here we have a group of scientists tracking an asteroid that measures nearly a mile in diameter, known as 1950 DA, to such a fine degree that they are able to predict an intercept course with Earth some 876 years from now and have even managed to pinpoint the area of impact - the Atlantic Ocean, about 350 miles from Cape Hatteras, N.C.
Since the big rock will hit the water at 38,000-miles-per-hour, it will have the same effect as a 60,000 megaton bomb. The asteroid will vaporize on impact, creating a cavity approximately 12 miles in diameter and reaching all the way down to the seafloor, which is about 3 miles deep at that point.
The computer-driven scenario shows that instead of creating one big tidal wave, the water rushing back in to fill the cavity results in a kind of ripple effect, a series of shock waves of varying frequencies and wavelengths that start out at about 16 feet in height and eventually reach tsunami dimensions of from 200 to more than 400 feet. At the end of one hour, 400-foot waves will have swept across the coasts of Virginia and the Carolinas, and within another hour, the entire East Coast will be deluged under 200-foot waves. Eight hours later, European coastal cities will be looking at a wall of water somewhere between 30 and 50 feet high.
The planetary scientists at UCSC are telling us that the probability of impact from 1950 DA is only about 0.03 percent, but they're also issuing cautions that yet-to-be-detected space rocks pose just as much of a threat. The supposed good news is that a NASA-led campaign to locate large asteroids in near-Earth orbits is about half way towards its goal of detecting 90 percent of those larger than a half-mile in diameter.
"Until we detect all the big ones and can predict their orbits," said Eric Asphaug, an associate professor of earth sciences, "we could be struck without warning. With the ongoing search campaigns, we'll probably be able to sound the "all clear" by 2030 for 90 percent of the impacts that could trigger a global catastrophe."
I don't know about anyone else, but I'm not particularly comforted by this information, for even when we reach 90 percent efficiency 27 years from now, what about the other 10 percent? What's really scary about all this is the fact that asteroid 1950 DA was discovered in 1950, studied for 17 days and then was lost for 50 years. It was rediscovered on New Year's Eve 2001. I wonder how many more sneaky asteroids there are out there?
I like the part about taking out D.C. But in 800 years, we really ought to do the job ourselves, a lot sooner.
Asteroid 1950 DA
http://neo.jpl.nasa.gov/1950da/
Asteroid Could Hit in 878 Years
Newsday ^ | 4/4/02 | Paul Recer
Posted on 04/04/2002 10:30:58 AM PST by areafiftyone
http://www.freerepublic.com/focus/f-news/659642/posts
Giant Asteroid May Strike Earth in 2880
The strike may generate tsunamis up to 122 meters high
Pravda ^ | 06/11/03 | Staff Writer
Posted on 06/16/2003 6:55:33 AM PDT by bedolido
http://www.freerepublic.com/focus/f-news/929818/posts
Massive Tsunami Sweeps Atlantic Coast In Asteroid Impact Scenario (Surf's Up)
UC Santa Cruz Press Release ^ | May 27, 2003 | UC Santa Cruz Press Release
Posted on 05/29/2003 9:57:14 AM PDT by Mike Darancette
http://www.freerepublic.com/focus/f-news/919723/posts
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