Thursday, 19 February 2015

It's out there, somewhere... and it's going to get us

As any devote of science fiction knows (or anyone who has seen the ludicrous films Deep Impact or Armageddon), life as we know it stands at risk from impact from celestial bodies such as asteroids or meteors.

Some people say that we should be taking this risk more seriously: whilst a major event may be very unlikely on a year-by-year basis, the results would be utterly catastrophic and should be guarded against.

Fortunately some people listened, and there is a global search for objects that could hit our tiny, insignificant (yet utterly wonderful) planet. Most of us would have heard of Halley's Comet, which deigns to visit us every 76 years, but there is so much more out there.

And we are finding more all the time.

The wonderful uber-geek-gamer-astronomer Scott Manley has produced a video showing all the asteroids discovered between 1980 and 2014. And there are a lot. A heck of a lot:

The three white objects rotating around the centre at speed are the innermost planets, Mercury, Venus and Earth. Mars is further out, and beyond that, at the edge of the video, can be seen Jupiter. The arcs of white dots are newly-discovered asteroids; green dots are already-discovered asteroids, whilst the red ones are the ones that are closest to, and most threatening to, Earth.

One day, one of these objects will be nudged from its orbit by collision, gravitational effects or even by forces with unpronounceable names. Fortunately Jupiter acts as a massive gravitational hooker that will attract many of these flirtatious objects, but some will make it into the inner solar system. Space is big and most will miss us, but one will occasionally get through.

The work to find and map these objects is relatively cheap (less, allegedly, than the production cost of either of the two aforementioned films), and knowing that they are there and their orbits are significant parts of the battle. Although the 2013 Chelyabinsk meteor evaded detection until it hit, scientists are getting better all the time at detecting them.

All we need now is training of Bruce Willis-types to go up to nuke the blighters if they get too close.

Or perhaps not...