October 23, 2013
Using Space Probes To Deflect Asteroids From Earth Trajectories
[ Watch the Video: Space Probes Could One Day Help Deflect Asteroids ]
Lee Rannals for redOrbit.com - Your Universe Online
Researchers at Fraunhofer Institute for High-Speed Dynamics have begun initial experiments to verify the possibility of deflecting asteroids by impacting them with heavy masses at high speeds. They said the principle behind their research is similar to how the balls in a game of billiards get banged around from one side of the table to another.
“During impact, not only does the probe transfer its own momentum to the asteroid, there is also the recoil of detached material from the crater, which is ejected against the direction of the impact,” Frank Schäfer of the Fraunhofer Institute said in a statement. “This recoil effect acts like a turbocharger on the deviation of the asteroid.”
The team attached various material with asteroid-like properties to a pendulum and impacted them with small aluminum projectiles. They discovered that the more porous the asteroid is, the less momentum is transferred, which means the projectile approach is particularly effective for denser space objects.
Researchers used high-speed cameras and laser interferometers to measure the pendulum’s swing during the study. This helped them demonstrate the transfer of momentum and the associated efficiency of the impact.
“In actual fact, the impact of a space probe would change the speed of the asteroid by just a few centimeters per second. But that’s enough to deflect its course to a significant degree over a longer period. So if we want to stop an asteroid on collision course with the Earth from hitting us, we’ll need to fire at it many years ahead of time,” Schäfer said.
Schäfer and his colleagues' test is part of the NEOShield space project. It brings specialists from Germany, France, the United Kingdom, Spain, the US and Russia together to work on ways to protect Earth from potentially hazardous asteroids. One of the project’s goals is to bring a mission to space by mid-2015 to actually deflect an asteroid.
In February, research like this team’s was shown to be especially important when a 10,000-ton meteorite exploded over Chelyabinsk in Russia, injuring almost 1,500 people. If this meteor had landed in a more populated area, it could have caused even more extensive damage. The Chelyabinsk meteor was just 65 feet in diameter, but the space rocks Schäfer and his colleagues are studying are between 325 feet and 980 feet in diameter.