I was watching the news the other day and they had a story on how in the year 2027 there will be a meteor which will circle around the earth and create 100ft tidal waves around the world. At this point they are predicting if it strikes in the atlantic ocean all of the east coast will be destroyed. This of course includes new york and florida also with the other states. Then after another 7 years the same meteor will be sucked in by the suns gravitational force and circle back around and come by earth again.
As a result, the number of asteroids that have been identified and reliably charted now stands at about 26,000, up from 10,000 in early 1999. ``And it took 198 years to get the first 10,000. That's how dramatically things are moving,'' said Brian Marsden, director of the Minor Planet Center of the International Astronomical Union, the international repository of data on asteroids, comets and meteors.
Scientists have identified and charted about 1,413 near-Earth asteroids, so called because their trajectories have the potential to intersect with Earth's orbit. Five hundred of those are 0.62 mile in diameter or larger.
A key unit of measure for asteroid hunters is the Astronomical Unit (AU), defined as the average distance between the Earth and the Sun, or 93 million miles.
The closest near-miss on record occurred December 9, 1994, when an object the size of a large house and called 1994-XM1 passed within 0.0007 AU, or 65,000 miles of Earth, well within the moon's orbit of 238,000 miles.
The next close-call for Earth is expected August 7, 2027, when a 0.62-mile-size object called 1999-AN10 passes just outside the lunar orbit at 0.00265 AU, or 245,000 miles.
Still uncertain is what authorities can do if scientists find an asteroid or comet on a collision course with Earth. ``I don't think we'd give Bruce Willis a call,'' joked Yeomans, referring to a role the actor played in the movie ``Armageddon.''
Scientists say the biggest threats should be known decades in advance, theoretically giving the world's leading nations enough time to organize a safe, effective response plan.
Some scientists favor space vehicles capable of pushing an Earth-bound object off course. Others suggest some objects could be shattered into dust by a well-aimed intercontinental ballistic missile.
But for the moment, NASA is working to gain a clearer understanding of the mass and weight of different objects, whether they be comets, stoney asteroids, chunks of solid iron, or space-going piles of rubble.
``There have been some studies trying to identify which characteristics of an asteroid or a comet we would need to know to deal with it effectively. We have to know its structure, its density, its size, its mass,'' Yeomans said.
NASA's NEAR Shoemaker mission to the asteroid Eros last February yielded a wealth of knowledge about the biggest space rocks. On July 4, 2005, the spacecraft Deep Impact is scheduled to blast a football-field-size crater into the comet Tempel-1 so that scientists can get an idea of what comets are made of.
``So, the first goal is to find 'em, track 'em and characterize each of the several classes,'' Yeomans said.
``The thinking is that, more than likely, we'll have several decades to deal with such a thing. And this might be a more rational approach than having nuclear arsenals at the ready, because in that case, the cure might be worse than the disease.''
2006-09-01
07:41:08
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