Solar-Powered Laser Spacecraft Could Prevent Apophis Hitting Earth in 2036

via technologyreview.com

Solar-Powered Laser Spacecraft Could Prevent Apophis Hitting Earth in 2036
Spacecraft equipped with lasers powered by light from the Sun are our best defence against incoming asteroids, say aerospace engineers

In 2004, the Earth crossing asteroid Apophis generated much interest when astronomers announced that there was a 2.7 per cent chance that it would hit the Earth in 2029.
The excitement died down when more detailed observations showed that Apophis would actually miss Earth in 2029. And yet, Apophis might still hit in 2036 or 2037--we simply cannot know until nearer the time.
An important question, then, is what to do if astronomers spot Apophis coming our way--what can we do to push this 46 million tonne object away?
Last year, we looked at a Chinese plan to deflect the asteroid by smashing a spacecraft into it using a solar sail.
Today, Massimiliano Vasile and Christie Maddock at the University of Strathclyde in Scotland reveal a plan to blast the asteroid with solar powered lasers, ablating its surface and steering it away from us. "[Our] paper demonstrates how significant deflections can be obtained with relatively small sized, easy-to-control spacecraft," they say.
Laser ablation is not a new ...