Space is a dangerous place, home to deadly radiation, inhospitable temperatures and unimaginable pressures. And even Earth is not immune from extraterrestrial peril, because very occasionally our planet is pummelled by killer asteroids. Now respected space scientist Bill Nye has revealed the original outlook could be even worse than feared, with thousands of asteroids out there yet to be to be identified.
Most asteroids are very small, and those less than 10 metres in diameter will simply burn up when they hot Earth’s atmosphere.
We are potentially missing a hundred thousand killer asteroids
Space rocks 25m – 45m in diameter, meanwhile, will result in a significant collision, resulting in cities or even entire county being wiped out.
Asteroids between 100m – 140m in size could obliterate a whole country and those bigger than that are known as continent killers.
While those asteroid of even larger dimensions will result in the death of entire races of species.
American science personality Bill Nye has revealed ”we are potentially missing a hundred thousand killer asteroids.”
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The popular American science commentator said on the AsapSCIENCE YouTube channel: “What we want to do is build a spacecraft called the Sentinel Craft.
“Searching for asteroids is like looking for a charcoal briquette in the dark; these things are hard to find.
“These asteroids are tiny compared to the vastness compared to the vastness of space.
“But infrared light and heat bounces off these asteroids.
“So surveying spacecraft are positioned with their backs to the Sun and look out from the orbit of Venus.”
Once such a deadly asteroid is discovered to be barrelling on a collision course with Earth, Mr Nye explains how they can be deflected.
He said: “We have got to deflect these asteroids, by just a tiny amount.
‘An asteroid might be travelling 10 km/s, and we want to change its speed about 2 mm/s.
“This will change the asteroid’s speed by a 10 millionth its total.
“But asteroids can come in at 10,000 – 100,000 tonnes, requiring a significant force to alter it by a 10 millionth of its speed.
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The Planetary Society charter member then explains the simplest way to achieve this change in trajectory.
Bill Nye said: “The easiest way is to set a large rocket on a collision course with the killer asteroid.
“This would change its speed a little.”
However this would not solve the problem if the asteroid was, in fact, a pile of rocks loosely held together by gravity.
For such an collision would simply cause the rocks to spread out, resulting in a deadly shower of space rocks.
The only option then, he explains, is to launch an even bigger spacecraft and send it near the asteroid.
“The mutual gravity of the asteroid and the spacecraft will tug the asteroids just a little bit,” he said
However, he says, this plan does come with its own drawback.
“We would need a huge amount of fuel for years.