Sep 25, 2009

Asteroid attack: Putting Earth’s defences to the test

Posted by in categories: asteroid/comet impacts, defense, existential risks

Peter Garretson from the Lifeboat Advisory Board appears in the latest edition of New Scientist:

“IT LOOKS inconsequential enough, the faint little spot moving leisurely across the sky. The mountain-top telescope that just detected it is taking it very seriously, though. It is an asteroid, one never seen before. Rapid-survey telescopes discover thousands of asteroids every year, but there’s something very particular about this one. The telescope’s software decides to wake several human astronomers with a text message they hoped they would never receive. The asteroid is on a collision course with Earth. It is the size of a skyscraper and it’s big enough to raze a city to the ground. Oh, and it will be here in three days.

Far-fetched it might seem, but this scenario is all too plausible. Certainly it is realistic enough that the US air force recently brought together scientists, military officers and emergency-response officials for the first time to assess the nation’s ability to cope, should it come to pass.

They were asked to imagine how their respective organisations would respond to a mythical asteroid called Innoculatus striking the Earth after just three days’ warning. The asteroid consisted of two parts: a pile of rubble 270 metres across which was destined to splash down in the Atlantic Ocean off the west coast of Africa, and a 50-metre-wide rock heading, in true Hollywood style, directly for Washington DC.

The exercise, which took place in December 2008, exposed the chilling dangers asteroids pose. Not only is there no plan for what to do when an asteroid hits, but our early-warning systems — which could make the difference between life and death — are woefully inadequate. The meeting provided just the wake-up call organiser Peter Garreston had hoped to create. He has long been concerned about the threat of an impact. “As a taxpayer, I would appreciate my air force taking a look at something that would be certainly as bad as nuclear terrorism in a city, and potentially a civilisation-ending event,” he says.”

Read the entire article at New Scientist. Read the NASA NEO report “Natural Impact Hazard Interagancy Deliberate Planning Exercise After Action Report”.


Comments — comments are now closed.

  1. John Hunt says:

    Every day that passes, the statistically predicted death toll from an asteroid impact goes down. This is because we are steadily detecting more and smaller asteroids including NEOs. The more we know the more time that we will have to prepare for evacuations or a deflection mission. The bigger the asteroid, the sooner we’ll detect it.

    The opposite is true for the big four existential threats: nanotech, biotech, AI, and self-replicating chemicals. Each day that passes, the risks from these grow. Scientists are advancing these technologies anticipating great benefits. But along with these benefits comes the threat of extinction which completely trumps any benefits.

    We need to generate attention and action on the greatest threats.


    An asteroid the volume of a sky scraper would be about 125 feet in diameter yielding the equivalent of a 120 megaton explosion. People would survive beyond about 100 miles from the epicenter. Walking at about 3 miles per hour it would take people 1.5 days to get to safety. So all that would be needed for most people to survive would be for scientists to announce their findings and the predicted epicenter. The mainstream media and resulting panic would result in voluntary evacuation. This would also be true for any resulting tsunami.

  2. John Hunt says:

    I know that this is off topic but the Lifeboat Foundation should be most interested in the implications of lunar water as it relates to an off-Earth self-sustaining colony…

    For the near-term I don’t think that the finding of trace amounts of water or hydroxyl groups on the top surface of the Moon makes much of a difference. It doesn’t fundamentally affect the Mars vs the Moon debate. If we go to the Moon first then we’ll still want to go the the lunar south pole as the concentration of water is likely much higher there. So the latest news doesn’t change that.

    I think that the key issue which nearly everyone seems to be overlooking is that the main purpose for going to the Moon or Mars needs to be to establish a self-sustaining off-Earth colony just in case someone develops self-replicating technology which destroys humanity on Earth. We’re talking either biotech, nanotech, AI, or self-replicating chemicals. This concern is not as far fetched as one might think. Each of these areas have a number of scientists actively moving us down that road, publishing their work openly, and that progress is not slowing but arguably is accelerating.

    All that we care about (life, family, progress, etc) is at risk. Think about it!

    So the questions should be this, “At which destination (Moon or Mars) can we develop a self-sustaining colony first?”. After we achieve that, then we can have the luxury of exploration, science, tourism, industry, etc.

    The martian atmosphere is helpful for aerobraking thereby reducing the need to bring extra propellant. Both Mars and the Moon presumably have sufficient water. But Mars has the advantage of readily available carbon & nitrogen — the Moon doesn’t. But sufficient C & N for a lunar colony can be transported with about two heavy launch vehicles.

    The proximity of the Moon is a big plus. Trips don’t have to be on a two year schedule. If something bad happens, lunar astronauts are only a three day trip away. Proximity also allows for remote-controlled robotic exploration, excavation, assembly, construction, etc. A three day trip also would require fewer supplies and simpler life-support system. Finally, the danger from radiation during transit would be less.

    Right now I think that the Moon has the advantage over Mars as the place where we can develop a self-sustaining colony the quickest.

  3. Roisin says:

    LOL I agree with NASAs own studies showing that sub-surface nuclear detonation being very effective, especially with a comet, as it would vaporize the ice and the kinetic force of this expansion would rip a comet to pieces.

    The “getting the warhead” into the heart of the object is a tricky one, especially something traveling at 30,000mph with any number of axial rotations.

    I heard we can grow diamonds now. Could a cone-shaped armor be created with an extremely sharp point. Created like a jig-saw to withstand outside force but to break apart outwards?

    If something like this impacts a comet/asteroid, being tubular it could provide a “channel” to move the exploding device into?

    It could even be filled with a solid/compressed liquids before detonation to give it a little more “oomph” for your buck.