They’re coming! They’re coming! It’s not if but only when that rocks from space collide with the Earth. There are tens of thousands of these potential missiles roaming the Solar System. The majority orbit the Sun between the paths of Mars and Jupiter. Most behave; however, there is a special group known as Near Earth Objects (NEOs) which occasionally put our planet in their crosshairs. We have clear evidence that in our planet’s long history some of these space rocks have changed the very nature of life on Earth. Just as recently (in geological time) as 66 million years ago, an asteroid as wide as Manhattan extinguished over 70% of all life forms on Earth. 50 thousand years ago a huge 50 meter meteorite smashed into the American southwest and sent a shockwave equivalent to 10 megatons. Another huge object exploded above the forests of the Tunguska River Valley in Siberia in 1908. And most recently, a 20 meter object exploded over the Russian city of Chelyabinsk in 2013 with the force equal to 400-500 kilotons. While it is true that asteroids and other space rocks can bring death and destruction, it is also believed that they were the carriers of much of Earth’s water and perhaps even the deliverers of the elements of life (if not life, itself).
There is no imminent threat as of this writing. I repeat ⎼ no imminent threat, but. . . ? We will explore the history, characteristics, and the future potential threat of these fascinating objects. We need to be informed because our very lives depend on it.