2012 DA14

So, the title doesn't really say what this post is about, so I'll explain here. Last year, an asteroid was spotted in 2012 and calculation of its orbit showed that the comet would have a close encounter with Earth on the 15th February 2013. How close? 0.09 lunar distances (the distance to the moon), which is just shy of 35 000 km. Thats quite a distance, but in astronomical (and in asteroid near miss terms), its not all that far. The comet is around 59 meters in diameter, so about half a rugby field accross. Thats not huge, but it is pretty big.

Just to put it in perspective, the comet will come within geosynchronous orbit of the Earth, which is where many of the satellites which we use on a daily basis sit. DSTV, GPS and telecomunication satellites all sit in geosynchronous orbit.

Now, don't get alarmed. Asteroid orbits are VERY accurately predicted, and this one WILL NOT impact Earth. Not now, or in any other of its upcoming orbits. I just wanted to let you all know that this hunk of rock will be saying "howzit" next week.

This asteroid is the largest object that has come this close to Earth in recent history, so it is quite exciting for those who are able to photograph such things. 

But, what if this baby did impact Earth. We've (probably) all see a doomsday movie where an asteroid impacts Earth and everyone dies. Well, this would be far less disastrous. In fact, the Earth has had run ins with similar sized objects in the past. For instance, in 1927, a similar sized object exploded in Siberia, Russia. The resulting blast was at least 3 megatons (and estimates say it could have been around 15 megatons, which is 1000 times more powerful than the atomic bomb dropped on Hiroshima), and it leveled 2000 square kilometers of trees.

Another object of similar size formed the Barringer crater in the USA, which stretches about 3 km accross. Below is a picture of this crater:

So, on the day after valentines day, cast your eyes upward, and think about what is going on up there, and how close 2012 DA14 is to us.