Scientists in Greenland have uncovered evidence for what may be the oldest impact crater ever found. And it would be hard to find one much older, because Greenland has some of the oldest exposed rock on earth. It’s also good it happened a long time ago — this impact was huge:
(MSNBC) — Researchers think the crater was formed 3 billion years ago, making it the oldest ever found, said Danish researcher Adam Garde. The impact crater currently measures about 62 miles (100 kilometers) from one side to another. But before it eroded, it was likely more than 310 miles (500 kilometers) wide, which would make it the biggest on Earth, Garde told OurAmazingPlanet.The team has calculated it was caused by a meteorite 19 miles (30 kilometers) wide — which, if it hit Earth today, would wipe out all higher life.
How bad would a 19 mile (30 km) wide object be if it hit today?
I assumed being 500 miles away while a 19 mile-wide object made of lighter rock or solid ice struck land at a 45 degree angle with a velocity of 20 miles per second. According to the Purdue University impact simulator, the fireball would be more than 1000 times brighter than the sun. A person caught in the open, clothes and hair would ignite, skin would suffer second and third degree burns. Just glancing at the fireball as it streaked across the sky or on the horizon would cook your retinas like tiny fried eggs.
One Big Impact