Inside Science) – Imagine you have just spotted a giant asteroid heading straight for Earth. What should you do? Blow it up? Tow it away? Some researchers think you should ask a computer.
Planetary defense experts have proposed three main methods for fending off a potential planet killer -- nuke it, crash something into it, or lure it away with the gravitational tug of a spacecraft. But not all asteroids are created equal, so one method may work better than another depending on the size, speed and distance of each incoming rock.
"We obviously don't have the money or time to develop and test all of [the methods]," said Erika Nesvold, an astrophysicist formerly at the Carnegie Institution for Science in Washington, D.C., during her presentation at this week's meeting of the American Astronomical Society in National Harbor, Maryland. "So we want to know how can we decide which of these technologies is most likely to work."
As part of a project lyrically named the Deflector Selector, Nesvold and her team simulated more than 18 million attempts to save us from asteroid-induced Armageddon. They then used part of the results to train a computer to determine the best way to stop an asteroid. They reserved the other part of the simulated results to test the computer afterwards. Once trained, the computer was able to make the call within minutes, compared to the days it took for the detailed simulations. Its recommendations matched the simulation results more than 90 percent of the time.
The researchers also found that for roughly one-quarter of the simulated scenarios, none of the three methods could have stopped the asteroid from hitting the Earth. Nesvold hopes their method can guide future efforts to develop better planetary defense tools, such as a better detection campaign or a faster rocket. It could save us from going the way of the dinosaurs.