Happy Valentine’s Day everyone! Instead of posting about how this day brings people together blah blah commercialization blah blah The Notebook, I though’t I’d address another meeting of heavenly bodies – and those are the Earth and asteroid 2012 DA14. As you may have seen in the news this asteroid will set a record for near-misses after it passes within 15,000 miles of Earth. This obviously begs the question, “what if it hit us”? As it turns out, we experienced something which caused an effect similar to what would happen in 2012 DA14 hit us: it happened near the Tunguska River in Siberia in 1908.
Shortly after 7am in the morning, settlers in the sparsely-populated region of Siberia reported seeing an extremely bright column of light in the sky. Shortly after this, they heard a loud boom – more specifically a sonic boom, which is caused when an object breaks the sound barrier. Then, everybody watching was hit by an intense shockwave that knocked them off their feet; windows were broken, seismic activity was registered at observer stations, and an estimated 80 million trees were literally flattened over an area of over 800 square miles. So what happened?
Unfortunately, nobody really knows. Theories concerning black holes, natural nuclear explosions, and even aliens have all been proposed. One of the most likely is that an object about the size of 2012 DA14 exploded during re-entry, releasing an incredible amount of stored up gas pressure. If this is the case, then the object likely originated from a comet that will pass by Earth again in 2045.
So how does this relate to our near-miss tomorrow? First off, 2012 DA14 is about 45 meters long and is traveling at 7.8km/sec, faster than a speeding bullet. If it did hit Earth, it would also likely explode in the atmosphere and release about 2.4 megatons of TNT’s worth of energy – about 150 Hiroshima bombs. This is roughly the same size of the explosion estimated to have created the Tunguska event, and would easily destroy any city with a direct hit. But don’t worry – NASA says that an impact is a virtual impossibility. I’m still watching Armageddon tonight though.