The Chelyabink meteor on Feb. 15, 2013. Константин Кудинов/Wikimedia photo

Bruce Willis Can’t Save Us From Asteroids, So We’ll Have to Save Ourselves

Some ideas for defending against the next asteroid impact

On Feb. 15, an asteroid exploded above Chelyabinsk, Russia with the force of 500 kilotons of TNT. Roughly the power of a tactical nuke.

The carnage was captured on dashboard cams across the area. Windows shattered and people were flash-burned and temporarily blinded—dramatically demonstrating the threat posed by near-earth objects, a.k.a. “NEOs.”

This will happen again. And since Bruce Willis is only an actor and Armageddon just a crappy action movie, we’ll have to protect ourselves.

On Nov. 6, Nature published two studies detailing the Chelyabinsk incident. The scientists found that the asteroid was in fact tiny: about 20 yards across.

Scientists had been concentrating on larger asteroids, the half-mile-long monsters that might end civilization should they impact the planet. Now there’s a whole other class of tinier, harder-to-detect threats to worry about.

When the cold hard void of space throws its rocks at us, what can we do to defend ourselves?

Dr. Fork says lasers can save us. University of Alabama in Huntsville photo

Space lasers, paintballs and redirection

Scientists at the University of Alabama in Huntsville think lasers are the answer. Their plan involves sending up a rocket mothership to orbit any NEOs that threaten the planet.

This mothership would deploy a number of tiny micro-spacecraft to circle the asteroid. Next, the lasers. The mothership shoots ultra-short laser bursts into the orbiting micro-spacecraft, acting as reflectors.

These tiny reflective craft focus the lasers onto the asteroid, super-heating its surface and causing debris to eject in plumes. This repeated spray of dust from tiny, super-hot holes, acts like a thruster, throwing the asteroid off course and deflecting any impact.

The best part of this plan, other than the beautiful image of tiny ships shooting lasers at space rocks? It’s cheap and all the technology is already on hand. “It’s doable in a few years if the effort is well funded,” said Richard Fork, lead scientist on the project. They've proposed their idea to NASA.

But paint could be a better method of deflecting asteroids. Shooting paint instead of lasers isn't as sexy, but it involves fewer moving parts.

In October 2012, Sung Woo Paek, a grad student at MIT, won the U.N.-sponsored “Move an Asteroid” competition with his paint-based proposal. It’s remarkably simple.

Paek proposed sending up tons and tons of white paint to splash any near-earth objects that poses a danger. The initial blast of paint pellets would send the asteroid off course, and the white paint would reflect the sun’s rays, pushing the object even farther off course.

The problem, however, is that the movement is so slight. The shift builds up over time, but for larger objects the paint would need to be in place for years to cause any meaningful change in course.

NASA has its own plans. Part of its proposed budget for 2014 involves increased funding so scientists can study NEOs and figure out how best to combat them. To that end, the space agency wants to capture an asteroid, bring it into a stable orbit around Earth and send a manned crew to the rock to study it.

The agency has also put out a request for information, looking for suggestions from the public and the private sector on how best to redirect asteroids. The synthesis of that information will be presented at a workshop in late November.

NASA’s previous study of asteroids, the Deep Impact mission from 2005 to 2007, involved crashing a probe into an asteroid and taking samples from within. All of this work is expensive, and NASA’s budget is often one of the first up on the chopping block when legislators talk about reducing government spending.

Russian scientists and the Russian Federal Space Agency have discussed asteroid defense proposals since the Chelyabinsk meteorite. One group of researchers at the Russian Academy of Sciences proposed capturing small space rocks — smaller than the one which exploded above Chelyabinsk — and flinging them in the path of larger asteroids.

But the Kremlin doesn't appear to be interested—and besides, such a plan would take at least a decade and cost billions of dollars to build.

And none of the plans for dealing with the asteroids will matter if we can’t detect them first.

The proposed Sentinel telescope. B612 Foundation art

See it before it strikes

NASA and other space agencies are good at detecting the larger risks. Giant civilization-ending nightmare rocks hurtling through the sky are hard to miss. But the Chelyabinsk-size threats are far harder to see in advance.

Dr. Edward Lu, a former astronaut, told The New York Times that astronomers had only discovered between 10 and 20 percent of the NEOs smaller than a half-mile across.

Lu wants to build a telescope — called the Sentinel — that’ll be used to detect these smaller asteroids before they have a chance to do any damage. But even the Sentinel isn't sharp-eyed enough to pick out asteroids of the size that blew up Chelyabinsk, and there just aren't a lot of good estimates about how many of those exist.

This is a global problem that’s going to require an international solution. In October, the U.N. adopted the International Asteroid Defense Plan, first proposed by the world body’s Committee on Peaceful Uses of Outer Space.

The plan calls for the open sharing information about space threats and the coordination of any space missions meant to deflect the incoming NEOs. But these initiatives are still in the early planning stages.

“Basically [it’s] the skeleton of a decision making process ... it has no meat or muscle on it yet,” said Rusty Schweickart, a former astronaut. “That’s the challenge for the next few years.”

The other challenge is structuring Russia’s research organizations and space agency for working more closely together. After Chelyabinsk, Russia’s space agency chief Vladimir Popovkin proposed a plan where the agency would stick to tracking dangerous space debris while leaving asteroid monitoring duties with the Academy of Sciences.

So in the end, a grand plan to defend Earth from asteroid impact is still in its infancy. NASA is moving forward with studies and Russia — the country most recently afflicted — has taken some early steps. The U.N. has a plan, at least, which could improve coordination between governments. There’s also a growing body of research from independent scientists and research institutes.

But Earth is still woefully unprepared.

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