Not long ago Earth experienced a ‘double barrel’ event from the skies, one a tiny ‘rock’ of about 17 meters (50 feet) in diameter that roared overhead in Russia, injuring about a thousand people and doing extensive damage, the other was an asteroid (2012 DA14) whose orbit carried it within 27,700 kilometers (21,000 miles) of the earth surface. [ScitechStory: The Day of the Asteroid and Meteor].
This twofer had the effect of alerting some in the public and a few in media to call for “DOING SOMETHING” about the asteroid menace. All to the good, of course. Unfortunately, in the United States it was generally ignored that the European Space Agency (ESA) already has plans for “doing something,” namely firing two rockets at asteroids to see if the impact has measurable effect.
Today (February 26, 2013) ESA announced that it has picked a target, the asteroid Didymos system, which will approach Earth at a distance of about 11 million kilometers in 2022. Didymos is a binary asteroid system, two asteroids, one 800 meters across, the other 150 meters. Both are much bigger than the two just seen over Earth. As part of the low budget AIDA (Asteroid Impact and Deflection Assessment) program, two small craft will be sent to crash probes on both asteroids. Scientists will study how this affects the orbital dynamics.
This is how we learn about protecting Earth from asteroids – by doing something, in advance.
