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Old 11-16-2012, 04:31 PM
 
15,924 posts, read 17,652,520 times
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Ahhhh pure rocket science here, Bruce Willis not required.....

Quote:
According to a new paper, the scientists and their paintball guns would blast an earth-bound asteroid with a ton of paintball pellets turning the rock blindingly white whereupon it would reflect enough sunlight to push it off its course of destruction.
United Nations: Paintball guns could save Earth from asteroids - NYPOST.com
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Old 11-16-2012, 05:27 PM
 
Location: Wasilla, Alaska
17,825 posts, read 20,501,852 times
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Quote:
Originally Posted by plwhit View Post
Ahhhh pure rocket science here, Bruce Willis not required.....



United Nations: Paintball guns could save Earth from asteroids - NYPOST.com
I would expect this kind of stupidity from the UN.

The Yarkovsky effect is so minimal that it will only work on small asteroids with low mass. For example, the Yarkovsky effect on asteroid 6489 Golevka, over a twelve year period from 1991 to 2003, managed to move the asteroid a whopping 15 kilometers. (9.4 miles).

A better means of moving an asteroid would be with a gravity tractor, or solar sails, or by directly pushing the asteroid, or a stand-off nuclear explosion, or a myriad of different possibilities, all of which are far better than this hair-brained scheme.
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Old 11-16-2012, 07:57 PM
 
Location: Portsmouth, VA
75 posts, read 76,333 times
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Originally Posted by Glitch View Post
I would expect this kind of stupidity from the UN.

The Yarkovsky effect is so minimal that it will only work on small asteroids with low mass. For example, the Yarkovsky effect on asteroid 6489 Golevka, over a twelve year period from 1991 to 2003, managed to move the asteroid a whopping 15 kilometers. (9.4 miles).
Actually the idea is not that bad if we notice the asteroid in sufficient time. It also has the advantage of being relatively cheap compared to some of the other options mentioned. The small amount that 6489 Golevka was moved would be more than sufficient to keep an asteroid predicted to collide with Earth from doing so. For example, the asteroid Apophis will be making a close approach to Earth in 2029. If during that approach, it passes through a gravitational keyhole only 1/2 mile wide, it could impact Earth when it returns in 2036. It would not have to be moved much more than that 1/2 mile.

99942 Apophis - Wikipedia, the free encyclopedia

Of course, you want to be pretty darned sure that all the calculations are right and no one drops a decimal point or uses a wrong sign. You might end up guaranteeing an impact instead of preventing one.
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Old 11-18-2012, 05:19 AM
 
Location: Wasilla, Alaska
17,825 posts, read 20,501,852 times
Reputation: 6500
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Originally Posted by theprask View Post
Actually the idea is not that bad if we notice the asteroid in sufficient time. It also has the advantage of being relatively cheap compared to some of the other options mentioned. The small amount that 6489 Golevka was moved would be more than sufficient to keep an asteroid predicted to collide with Earth from doing so. For example, the asteroid Apophis will be making a close approach to Earth in 2029. If during that approach, it passes through a gravitational keyhole only 1/2 mile wide, it could impact Earth when it returns in 2036. It would not have to be moved much more than that 1/2 mile.

99942 Apophis - Wikipedia, the free encyclopedia

Of course, you want to be pretty darned sure that all the calculations are right and no one drops a decimal point or uses a wrong sign. You might end up guaranteeing an impact instead of preventing one.
It is an horrendous idea. In order to move an asteroid/comet just one Earth radii using the Yarkovsky effect would require an advance notice of at least 5,103 years. NASA is not capable of predicting the orbits of asteroids more than a few years out with any sort of accuracy. Apophis, for example, is not going to hit the Earth this century, not in 2029 or 2036, and at least not before 2103. They recently reduced Apophis to Torino Scale of 0.

There are currently two asteroids with a Torino Scale of 1, 2011 AG5 and 2007 VK184. 2011 AG5 has a 1 in 200 chance of impacting the Earth in 2040, and 2007 VK184 has a 1 in 5,700 chance of impacting the Earth in 2048. Both asteroids are less than 150 meters in diameter. That is not sufficient time to move either asteroid using the Yarkovsky effect.

Source: Current Impact Risks
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Old 11-18-2012, 07:31 AM
 
Location: Portsmouth, VA
75 posts, read 76,333 times
Reputation: 100
Quote:
Originally Posted by Glitch View Post
It is an horrendous idea. In order to move an asteroid/comet just one Earth radii using the Yarkovsky effect would require an advance notice of at least 5,103 years. NASA is not capable of predicting the orbits of asteroids more than a few years out with any sort of accuracy. Apophis, for example, is not going to hit the Earth this century, not in 2029 or 2036, and at least not before 2103. They recently reduced Apophis to Torino Scale of 0.

There are currently two asteroids with a Torino Scale of 1, 2011 AG5 and 2007 VK184. 2011 AG5 has a 1 in 200 chance of impacting the Earth in 2040, and 2007 VK184 has a 1 in 5,700 chance of impacting the Earth in 2048. Both asteroids are less than 150 meters in diameter. That is not sufficient time to move either asteroid using the Yarkovsky effect.

Source: Current Impact Risks
I know Apophis is not going to hit the Earth, but you are missing my point. IF there were a chance that it might, you only have to move it a half mile, less than one kilometer for it to miss. You keep mentioning motions in terms large distances, 15 kilometers, 1 Earth radius. Such large changes are not necessary. The longer warning you have, the smaller the change needed to deflect the thing.
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Old 11-18-2012, 11:23 PM
 
Location: Wasilla, Alaska
17,825 posts, read 20,501,852 times
Reputation: 6500
Quote:
Originally Posted by theprask View Post
I know Apophis is not going to hit the Earth, but you are missing my point. IF there were a chance that it might, you only have to move it a half mile, less than one kilometer for it to miss. You keep mentioning motions in terms large distances, 15 kilometers, 1 Earth radius. Such large changes are not necessary. The longer warning you have, the smaller the change needed to deflect the thing.
That is incorrect. The half mile you keep referring to was a keyhole that if Apophis passed through in 2029 it would return to impact the Earth in 2036. NASA/JPL could not even tell, until recently, whether or not Apophis would pass through that keyhole. They certainly cannot say where any future asteroid will impact the planet when they barely know when or even if it will impact the planet. By the time they are certain of an impact, it will be too late to use the Yarkovsky effect.
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