How to deflect asteroids and save the Earth
April 16, 2009You may want to thank David French in advance. Because, in the event that a comet or asteroid comes hurtling toward Earth, he may be the guy responsible for saving the entire planet.
French, a doctoral candidate in aerospace engineering at North Carolina State University, has determined a way to effectively divert asteroids and other threatening objects from impacting Earth by attaching a long tether and ballast to the incoming object. By attaching the ballast, French explains, "you change the object's center of mass, effectively changing the object's orbit and allowing it to pass by the Earth, rather than impacting it."
Sound far-fetched? NASA's Near Earth Object Program has identified more than 1,000 "potentially hazardous asteroids" and they are finding more all the time. "While none of these objects is currently projected to hit Earth in the near future, slight changes in the orbits of these bodies, which could be caused by the gravitational pull of other objects, push from the solar wind, or some other effect could cause an intersection," French explains.
So French, and NC State Associate Professor of Mechanical and Aerospace Engineering Andre Mazzoleni, studied whether an asteroid-tether-ballast system could effectively alter the motion of an asteroid to ensure it missed hitting Earth. The answer? Yes.
"It's hard to imagine the scale of both the problem and the potential solutions," French says. "The Earth has been hit by objects from space many times before, so we know how bad the effects could be. For example, about 65 million years ago, a very large asteroid is thought to have hit the Earth in the southern Gulf of Mexico, wiping out the dinosaurs, and, in 1907, a very small airburst of a comet over Siberia flattened a forest over an area equal in size to New York City. The scale of our solution is similarly hard to imagine.
"Using a tether somewhere between 1,000 kilometers (roughly the distance from Raleigh to Miami) to 100,000 kilometers (you could wrap this around the Earth two and a half times) to divert an asteroid sounds extreme. But compare it to other schemes," French says, "They are all pretty far out. Other schemes include: a call for painting the asteroids in order to alter how light may influence their orbit; a plan that would guide a second asteroid into the threatening one; and of course, there are nukes. Nuclear weapons are an intriguing possibility, but have considerable political and technical obstacles. Would the rest of the world trust us to nuke an asteroid? Would we trust anyone else? And would the asteroid break into multiple asteroids, giving us more problems to solve?"
The research was first presented last month at the NC State Graduate Student Research Symposium in Raleigh, N.C. The research, "Trajectory Diversion of an Earth-Threatening Asteroid via Elastic, Massive Tether-Ballast System," has also been reviewed and accepted for presentation this September at the American Institute of Aeronautics and Astronautics SPACE 2009 Conference and Exposition in Pasadena, CA.
Source: North Carolina State University (news : web)
Oct 12, 2006 |
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2. heading in the opposite direction at appx. 20 to 30 thousand miles an hour,
3. have that space ship haul a 1000 to 100,000 kilometer tether connected to
4. a huge ballast (iron ball?)
5. attached said Rube Goldbert mechanism to the asteroid after landing on it, and then,
6. wait and see what happens.....
7. Okay.....
b. This tether won't be deflecting an asteroid on the final run of a collision course, but may work over several years.
Given a and b, why not land a mining machine, either powered by a massive solar array or by several tonnes of concentrated nuclear waste. Mine whatever the asteroid has in abundance (or even just cut it up into small enough pieces). Fling the mined stuff (or bits of asteroid) into space, with a rail gun, solar steam cannon, whatever, in the direction that will deflect the asteroid orbit wherever you want (maybe just aim at North Korea).
So the asteroid misses (or hits someone we don't like) and the mining machine can keep flinging mined stuff in useful directions.
The mining machine could also produce some sort of paint (eg soot, platinum dust) and fling this at less than escape velocity, eventually painting much of the surface. This would also help change the orbit.
Chance of anchoring a tether to a pile of gravel or a snowball is slim to none.
Probability of building a long enough tether.
Probability of moving the counter-mass.
The probability of doing all this in time is the probability of humanity surviving long enough to control that much energy - slim to none.
Prepare to be assimilated by the BOG Obongo. Resistance to Obamination is futile. BOG Brother is watching - OBEY. It is hopeless. Invest in SOYLENT INDUSTRIES. Hank Reardon and John Gault were stillborn.
Although they did use an appropriate (how many times around the world) analogy. This is what I require in order to understand the physical world around me. Having been around the world,... let's see ... zero times.
I propose that we send midgets on very small spaceships and with machine gun to blast the asteroids into oblivion.
Or get one of those giant, really long scissor type extensions with a boxing glove on the end and knock it out of orbit.
@Solego
Um... making a tether that can run a space elevator - possible and even probable.
Making a tether that won't break when the counterweight reaches the end of the line...ain't gonna happen!
Honestly, the forces involved for having an object (counterweight on tether) instantly change direction from 12,000mph one way to 30,000mph the opposite way... well, lets just say you would have better luck trying to steer it off course by having a staring contest with it!