Giant Meteorite Struck Earth
Once upon a time—over 3billion years ago—a giant meteorite that was 4 times bigger than today’s MountEverest struck Earth. This meteorite was 200 times larger than the one thatwiped out the dinosaurs. But when it struck, it may have given ancientmicroscopic life forms a boost.
This impact happenedwhen Earth was very different than the planet we know today. At that time, lifeon Earth consisted only of simple bacteria and similar single-celled organisms.
It is postulated thatback then, shorelines were shelves of shallow water, which would have been alow-energy environment without strong currents. After the impact, giant tsunamiswould have swept the planet, ripping up the sea floor. The ocean’s surfaceboiled and so much dust was thrown up that it blocked out the sun.
Life, however, provedresilient. Ancient rocks from South Africa show that bacteria not onlysurvived, it thrived in the aftermath. The impact stirred up iron from theocean depths and delivered phosphorus (both from the meteorite and by increasederosion on land). This meant that certain bacteria that feed on these elementscould flourish.
The site in SouthAfrica where this evidence was found indicates there were at least 8 differentmajor meteorite impacts from Earth’s early history.
