How were scientists able to come to the (pretty much universally accepted) conclusion that it was a meteor that killed the dinosaurs when no one was around to witness it?

Question

Is it even remotely possible it was something else that happened around the same time?

In: 0

Answer 1

The earth itself keeps a pretty stable record of what happens on it, if you know how to read it.

When you take samples of the ground, you get sort of layers. Different colours and soil types show up in more or less clear segments. When we look at the soil from ~66 million years ago, we find a layer of soot. Enough soot that it would have significantly weakened the sun’s influence on earth’s life.

Around 66 million years ago is also when we find a lot of dinosaur fossils (other fossils as well). After that period, we don’t really find any dinosaur fossils anymore. That means they must have gone extinct.

The reason we believe an asteroid caused that soot to cloud the atmosphere is that we found the crater. It’s off the Mexican coast. Any life in the area would have died out instantly, but the soot and other stuff it launched into the atmosphere killed the rest. Roughly 75% of mammals are estimated to have died during a period of ~30,000 years.