Until recently it was thought that the chances for big space rocks to hit Earth are about one at a million, but a recent study lead by a Columbia University geophysicist named Dallas Abbott indicates that those odds may not be correct.

Geologists have considered that cannot be calculate the number of asteroids in space by those on Earths surface. Dallas Abbott however has considered the fact that Earth's surface is about 70% covered with water, so she started looking for craters undersea. Not only he found as many craters as those found on ground, but he discovered that an asteroid measuring three to five kilometers across, hit the Indian Ocean about 4.800 years ago, causing a huge tsunami.

Not only does this study suggest that danger of an impact is higher than we have though, but space images from a different space ships have also shown that there are more asteroids and comets than we would have expected.

If Abbott's conclusions are correct, then chances for Earth to be hit by an asteroid are higher and they are growing.