Close call coming: Averting the asteroid threat–Simple! Ask the Lightbringers

With an errant space rock heading this way, just how good are our asteroid defences – and how do we avert the cataclysm?

IT COULD easily be the plot for a Hollywood disaster movie. Last February, a young dental surgeon called Jaime Nomen was sailing along the Mediterranean coast of Spain, checking images on his laptop from an observatory 600 kilometres away. Suddenly he spotted a speck of light speeding through the constellation Boötes. Nomen knew exactly what it was.

He alerted the Minor Planet Center in Cambridge, Massachusetts, which collects information about asteroids and comets. Telescopes around the world swung into action, checking the new asteroid's orbit. The result was sensational: asteroid 2012 DA14 was on near-collision course with the Earth. (New Scientist; registration required.)

Maybe they’ll start looking somewhere else for Goldilocks Heaven?

No ultimate judge

Shockingly, Earth – which used to be smack-bang in the middle of our sun's habitable zone – is now a scant million kilometres away from the warm edge, so almost too hot for liquid water. Of course, we know Earth is robustly life-friendly – the mismatch is probably because neither definition accounts for clouds, which reflect sunlight away from Earth.

As Earth shows, the Goldilocks zone is no ultimate judge of habitability, something exoplanet researchers have known for years. As well as clouds, volcanic activity or the location of other moons or planets in the solar system, may be important for life to develop on planets like Earth.

Ring Any Bells?

Sandy! What have you been up to?

Only joking! Cheers