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asteroid

 
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abcgood



Joined: 27 Dec 2003
Posts: 34
Location: Taiwan

PostPosted: Sat Feb 12, 2005 6:36 pm    Post subject: asteroid Reply with quote

asteroid

There are many thousands of asteroids circling the sun in orbits between Earth and the other planet .

What are the chances that an asteroid will one day collide with Earth? The answer is: nobody knows.

There is a lot of evidence that asteroids have collided with Earth in the past, causing terrible damage.
What can be done to prevent such collisions from happening in the future?
Experts agree that our hope for preventing such collisions is to have advance warning of their approach.

If an asteroid does someday hit Earth, what exactly will happen?
That depends on the asteroid's size.
A small asteroid, 50 meters across, would hit Earth with a destructive force equal to that of the most powerful nuclear bomb.
It would destroy a city in minutes.
An asteroid twice that size would have 10 times the destructive power and could flatten most of a continent.
It could mean the end of life on Earth.(the end of world)
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Bob S.



Joined: 29 Apr 2004
Posts: 1767
Location: So. Cal

PostPosted: Wed Feb 23, 2005 1:30 pm    Post subject: Re: asteroid Reply with quote

abcgood wrote:
What are the chances that an asteroid will one day collide with Earth? The answer is: nobody knows.

The answer is, probably 100% if the geologic record of past events is any indication of future events. The question is: When? The last big impact capable of destruction on a mass scale was the Tunguska Impact of 1908 in Siberia.
See: http://en.wikipedia.org/wiki/Tunguska_event
Such city-killer impacts are estimated to occur every 100 years or so. Nation-blasting impacts occur every million years, and extinction level impacts every 100 million years or so (the last one happening about 65 million years ago).
See: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980419c.html
abcgood wrote:
What can be done to prevent such collisions from happening in the future?
Experts agree that our hope for preventing such collisions is to have advance warning of their approach.

Even with advanced warning, the answer is nothing with our current level of technology. Depending on how small it is and how much warning, it might be possible to mount some kind of Deep Impact http://www.imdb.com/title/tt0120647/ type mission to shatter it or push it off course. But that requires far more global cooperation and commitment than anyone on the planet has been willing to show since the Allied forces defeated the fascists during WWII.
abcgood wrote:
If an asteroid does someday hit Earth, what exactly will happen?
That depends on the asteroid's size.
A small asteroid, 50 meters across, would hit Earth with a destructive force equal to that of the most powerful nuclear bomb.
It would destroy a city in minutes.
An asteroid twice that size would have 10 times the destructive power and could flatten most of a continent.
It could mean the end of life on Earth.(the end of world)

Point taken, but your scale is a bit off. It's believed that an asteroid 15,000 meters across caused the extinction of all life bigger than a 'possum 65 million years ago. So something 500 meters across wouldn't likely end all life on Earth, it sure would make things uncomfortable for humans if it hit in the ocean (causing a massive tsunami) or sent up so much dust in the air it caused a prolonged winter devistating world agriculture.
See: http://impact.arc.nasa.gov/congress/index.html
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CE45



Joined: 15 Sep 2005
Posts: 15

PostPosted: Thu Sep 22, 2005 12:19 am    Post subject: Asteroid may hit the Earth Reply with quote

Much of our understanding about asteroids comes from examining pieces of space debris that fall to the surface of Earth. Asteroids that are on a collision course with Earth are called meteoroids. When a meteoroid strikes our atmosphere at high velocity, friction causes this chunk of space matter to incinerate in a streak of light known as a meteoroid. If the meteoroid does not burn up completely, what's left strikes Earth's surface and is called a meteorite. Asteroids are rocky and metallic objects that orbit around the Sun .Itís composed of three materials, 92.8 percent are composed of silicate (stone), and 5.7 percent are composed of iron and nickel. Itís have a diameter of 1kilometers or greater the largest are near Earth. I think its can hit earth because three reason.
First, most of the asteroids orbits the Sun between Mars and Jupiter in a "Main Asteroid Belt" that is centered around 2.7 times the Earth-Sun distance. Most near the Earth asteroids are believed to be main belt asteroids that were knocked out of the belt by collisions with other asteroids and by the gravitational forces of Jupiter and sometime the orbit have very elliptical orbits which bring them very close to Earth. They are compute by a program called Spacewatch. The program has found over 100 times more near Earth. Over 50 of these objects pass within the moon's orbit each day. They range in size from about 30% the diameter of our moon.
Second, in the solar system have many asteroids. In number, there are million of asteroids in the solar system. Astronomers have studied a number of asteroids by the photographed by a wide-field telescope (Hubble Space Telescope). From the number of it, scientists predict its have change to strike the Earth in the year 2008.
Finally, from the predict of scientist in the future asteroids may hit the Earth and it can destroy all life in the world like in dinosaur period but in my view before asteroid hit the Earth the human can eliminate it by our technology like in the movie ďArmagedonĒ. What do you think about asteroid may hit the Earth?
Shocked Adithep Roobleak 47210965 Civil Engineering Group16 Shocked
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Schlakoblok



Joined: 26 Sep 2005
Posts: 10

PostPosted: Mon Oct 10, 2005 10:34 pm    Post subject: Reply with quote

abcgood, can you write, what name has this asteroid, i can't remember. P.S. Your topic is interesting.
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