Posted on 01/30/2008 3:46:10 PM PST by blam
Could An Asteroid Hit Planet Earth, Again?
Asteroid impact on early Earth. Some scientists believe that impacts such as this during the Late Heavy Bombardment period, 4 billion years ago, may have delivered primitive life to Earth. (Credit: Copyright Don Davis)
ScienceDaily (Jan. 30, 2008) — Earth dodged a bullet today, when asteroid TU24 passed within 540,000 kilometers of our planet, which is just down the street on a galactic scale. Tomorrow, another asteroid – 2007 WD5 – will zip past Mars at a distance of only 26,000 kilometers away. Will we dodge the bullet the next time a near-Earth object (NEO) hurtles dangerously close to our home planet?
To mark the 100th anniversary of the Tunguska event, when an exploding asteroid leveled 2000 square kilometers of Siberian forest, The Planetary Society today kicked off a year-long focus on Target Earth. The asteroid believed responsible for the cataclysm on June 30, 1908 became a fireball from the sky and knocked pine trees over like matchsticks near the Podkamennaya Tunguska River in Russia. Such an explosion today over more populated areas could lay waste an entire city.
“The solar system is a busy place,” said Louis Friedman, Executive Director of The Planetary Society. “In fact, we live in a dangerous neighborhood, and keeping track of NEOs is like organizing a Neighborhood Watch in our corner of space.”
Earth has been hit by NEOs many times in the past; ancient craters are still visible in landforms around the world. The famed Meteor Crater in Arizona and Canada’s Lake Manicouagan are only two examples.
Target Earth will focus on a variety of NEO projects supported by The Planetary Society, including the Apophis Mission Design Competition, the Gene Shoemaker Near Earth Object Grants, NEO mission advocacy, and a one-hour HD TV “Daily Planet” special on asteroids being produced by Discovery Canada.
In mid-to late February, the Society will announce the winners of the Apophis Mission Design Competition, which invited participants to compete for $50,000 in prizes by designing a mission to rendezvous with and "tag" a potentially dangerous near-Earth asteroid. The competition received 37 mission proposals from 19 countries on 6 continents.
Tagging may be necessary to track an asteroid accurately enough to determine whether it will impact Earth, thus helping space agencies to decide whether to mount a deflection mission to alter its orbit. Apophis is an approximately 400-meter NEO, which will come closer to Earth in 2029 than the orbit of our geostationary satellites – close enough to be visible to the naked eye. If Apophis passes through a several hundred-meter wide "keyhole" in 2029, it will impact Earth in 2036. While current estimates rate the probability of impact as very low, Apophis is being used as an example to enable design of a broader type of mission to any potentially dangerous asteroid.
"Target Earth encompasses The Planetary Society’s three-pronged approach to NEO research,” said Director of Projects Bruce Betts. "We fund researchers who discover and track asteroids, advocate greater NEO research funding by the government, and help spur the development of possible ways to avert disaster should a potentially dangerous asteroid be discovered."
The Society will call for another round of Shoemaker grant proposals in the summer of 2008. One past grant recipient, Roy Tucker from Arizona, co-discovered Apophis. Many other past recipients from around the world continue to discover, track, and characterize NEOs.
NASA currently has no plans to study methods of asteroid deflection, or how to tag an asteroid for precise tracking. NASA and the European Space Agency (ESA) have co-sponsored the Society’s Apophis competition and will study the best mission designs offered.
The $50,000 in prize money for the Apophis Mission Design competition was contributed by The Planetary Society's Chairman of the Board, Dan Geraci, together with donations from Planetary Society members around the world. Funding for the Gene Shoemaker NEO Grant program comes from Planetary Society members.
Adapted from materials provided by Planetary Society.
I think one just hit Florida
If Hillary becomes president, I hope an asteroid hits to put us out of our misery.
With the state our country is in right now I almost wish an asteroid WOULD strike earth and put us all out of our misery.
my dad had asteroids... sometimes he couldn’t sit down for days.
Well, I did promise Mrs. Othniel the stars. Too bad it's a falling one....a rather BIG falling one....
Washington, D.C., January 20, 2009.....
As President-Elect Hillary Rodham Clinton raises her hand to take the oath of office, a ball of fire is seen on the horizon.
“I, Hillary Rodham Clinton....” BOOM!
Sith Lords, obviously.
I’d better move my car.
michael moore is an assteroid, among other things.
So an assteroid is something like a hemorrhoid, only much larger?
Can we steer it towards the stadium the next time Michigan and Ohio State play each other in football?
HE ruled out floods. HE didn’t say anything about a big celestial betch slap with an asteroid. I can think of a few people who would deserve it too......all of us. For we are all sinners and the wages of sin are death.
“Why do we have asteroids in the heavens - and hemorrhoids on our a$$?”
I would settle for one putting her out of our misery...
“Nemesis is a hypothetical red dwarf or brown dwarf star, orbiting the Sun at a distance of about 50,000 to 100,000 AU, somewhat beyond the Oort cloud. The existence of this star was postulated in an attempt to explain an inferred periodicity in the rate of biological extinction in the geological record.”
From Wiki.
Matese and Whitman have suggested that the supposed extinction periodicity might be caused by the solar system oscillating across the galactic plane of the Milky Way. These oscillations may lead to gravitational disturbances in the Oort cloud with the same proposed consequences as the orbit of “Nemesis”. However, the period of oscillation is not well-constrained observationally, and may differ from the needed 26 million years by as much as 40%.
See posts #34 & 35. I believe there are some cycles.
Try reading the book, "Cosmic Winter", Clube & Napier and the one below
Take a look at the moon.This planet has been hit over it’s surface just like that-wind and water erosion remove or mask the craters here.
Typically, asteroids orbit the Sun. Current estimates put the total number of asteroids above 1 km in diameter in the solar system to be between 1.1 and 1.9 million.
Fortunately, only a small number of these have an orbit that could ever intersect ours. For the larger of these, it would not be unreasonable to create an unmanned nuclear pulse projection spaceship to push it out of its trajectory, based on the Project Orion spaceship, but with a very different design.
This was a system by which fission or thermonuclear explosives would be detonated about 60 meters away from a very large steel or aluminum push plate to propel the spaceship. Oddly enough, the spaceship design needed giant shock absorbers attached to the push plate, that would also be needed to prevent the asteroid from the possibility of being fractured by the explosion.
Most likely, it would look like two giant metal plates with immense shock absorbers between them. In the middle of the outer plate would be a panel from which to eject the nuclear explosives.
Now granted, weighing in at 1.3 billion tons, a 1 km asteroid will not be greatly moved by even a thermonuclear detonation. But even a tiny movement will be tremendously magnified over the distance the asteroid travels—if it happens far enough away.
Yeah, there’s a lot of “stuff” out there competing for acceptance, and grants, I suppose. I’m not so sure we’ll ever get all the answers we’d like, and even if we do, they may get lost in the cacophony of competing theories. Given the state of the “scientific community”, one must resist putting too much faith in the pronouncements of scientific concensus; since it usually isn’t.
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