excerpts
Matt Genge, a space researcher at Imperial College, London, has calculated that something with the mass, acceleration and thrust of a small car could push an asteroid weighing a billion tonnes out of the path of Earth in just 75 days.
Gianmarco Radice, an asteroid expert at Glasgow University, said the best approach would be to land a device to dig into the object. "You could place something on the surface to eject material that would push the asteroid in the other direction."
Mirrors, lights and even paint could change the way the object absorbed light and heat enough to shift its direction over 20 years or so. With less notice, mankind could be forced to take more drastic measures, such as setting off a massive explosion on or near the object to change its course. In 2005, Nasa's Deep Impact mission tested a different technique when it placed an object into the path of a comet.
Dr Radice said robots could do the job just as well, doing away with the need for a risky and expensive manned mission. Last year Japan showed with its Hayabusa probe that a remote spacecraft can land on an asteroid.
But with manned missions to the moon and possibly Mars on its to-do list again, Nasa is keen to extend the reach of its astronauts.
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Europe has its own efforts to tackle asteroids. Its planned Don Quijote mission will launch two robot spacecraft, one to tilt at a harmless passing space rock, and a second to film the collision and watch for any deviation in the asteroid's path.
'Not if, but when...' Hits and near misses
At Nasa's Jet Propulsion Laboratory, in California, scientists monitor all "potentially hazardous asteroids" that might one day end up on a collision course with Earth. So far they number 831. The next close-ish shave - at a mere 17 times the distance from the Sun to the Earth - will be asteroid 2004QD14 on November 29.
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A near miss, when asteroid QW7 came within 4m km of Earth in September 2000, led Liberal Democrat MP Lembit Opik to declare: "It's not a case of if we will be hit, it is a question of when. Each of us is 750 times more likely to be killed by an asteroid than to win this weekend's lottery."
And the mass of a small car and 75 days of fuel is_______? Now add the mass of the vehicle to get the small car and 75 days of fuel to an asteroid more than 75 days out.
I think I'd rather watch the impact, knowing the Universe just became, over all, much smarter.
Either we are equal or we are not. Good people should be armed where they will, with wits and guns. NRA KMA
The chances are an asteroid hitting the earth would splash into an ocean or a virtually uninhabited area like the Sahara or Siberia. We should wait until the time and place of impact can be calculated more precisely. If it's going to hit someplace valuable, try to deflect it. If it's going to hit a wasteland or Iran, leave it alone.
???
17 AUs = 1,581,000,000 miles.
Right now Saturn is "only" 9.1 AU from Earth
Uranus is 19.7 AU from Earth.
Methinks there is a mistake in the number given in the article.
Perhaps they are talking about 17 times the distance between the Earth and Moon. That would be a more believable "close encounter" of only 6,800,000 miles (approx)