Monday, July 2, 2012

Earth was hit many times by asteroids

If Earth were to be hit by massive asteroid in years to come there could be even a chance of complete destruction of all life on our planet, including our own.  In its past, Earth was many times hit by large asteroids, and scientists are constantly finding new impact crates sites.

Up to now, there has been discovered around 180 impact crater sites. Up to recently the largest and oldest known crater was the 300 kilometre wide Vredefort crater in South Africa, 2 billion years in age.

The latest study by EU scientists has discovered the oldest crater in Greenland,  estimated to have occurred between 3 and 4 billion years ago.This is a 100 kilometre-wide crater located near the Maniitsoq region of West Greenland.. It took scientists three years to gather enough evidence that convinced the scientific community that this is an indeed a giant impact crater.

This discovery should greatly benefit science by enabling them the insight into the effects of cratering on the Earth in such distant past. Scientists have also reported that they were extremely lucky to find this crater, given the astronomically low chances as the result of erosion and covering by younger rocks.

In a very distant past Earth often experienced collisions with asteroids, primarily because it had much bigger gravitational mass.

Asteroids are not only potential doomsday carriers, the craters where impact took place are often the source of many elements and minerals or oil and gas.

One Canadian company is already using the impact model to explore for deposits of valuable nickel and platinum metals at Maniitsoq.