I have quite a fascination for them actually. Not the type travelling harmlessly around the asteroid belt though, oh no, I like the concept of one hurtling towards Earth and threatening to wipe us all out, and more importantly, what we would – and could – do about it.
We’re making advances in space travel, sending probes and what not further out, preparing to send people to live on Mars, identifying planets that could quite possibly sustain life… but what are our chances of stopping (or diverting) a killer asteroid?
I’ve watched films with this concept – Armageddon, Deep Impact, and several b-grade movies on the sci-fi channel whose film names escape me, possibly because they were beyond awful.
[spoiler] In Armageddon, a drilling crew lands on the approaching asteroid, somehow managing to drill through titanium plate and blow the rock to smithereens.
The crew of Deep Impact aren’t as lucky as Team Armageddon. They only manage to blow the asteroid into two pieces, and while the larger part cruises off into deep space, the smaller part enters Earth’s atmosphere with some amazing special effects, and with a lesser destructive force than the whole.[/spoiler]
Near Earth Objects
Nasa’s Near Earth Object Program was established in 1998 with a view to identifying near-earth asteroids larger than one kilometre. The chart on the left shows the total number of near-earth objects in relation to those over one kilometre.
While the chart seems to show quite a few close approaches, the asteroids that get a mention in the media are usually the ones that come closer than the norm, such as asteroid 2012 XE54 in December 2012 – a mere 143,000 miles away.
The tracking carried out by the Near Earth Object Program appears to be a preventive measure, as NASA ‘works with partners in the U.S. and around the world to detect, track and characterize NEOs, especially those that might pose a threat to human populations’ (source)
Physical protection from asteroids
There is a Wikipedia discussing methods of Asteroid impact avoidance, such as nuclear devices and deflection, but as I am unsure how much is fact, and how much is speculation, I’m going to pass on mentioning them for now.