This Is What Matters When It Comes to Extinction-Level Asteroids
It’s as much about what it hits here on Earth.
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00:00A giant meteor may have wiped out the dinosaurs hundreds of millions of years ago, but now
00:08experts are saying that the size of the impactor might not matter.
00:12We believe the dinosaurs died because when an asteroid hit the earth, it sent a cloud
00:15of dust into the air.
00:17That cloud blacked out the sun and killed much of the plant life on the planet.
00:20Then the herbivores didn't have anything to eat, and so on.
00:23So the bigger the asteroid, the bigger the dust cloud, the bigger the extinction event,
00:27right?
00:28Well, maybe not.
00:29Scientists found that a 30-mile-wide impact crater, the fourth largest ever discovered,
00:33had no impact on global life.
00:34It just carried on.
00:36Meanwhile, another that was half its size coincided with an extinction period 5 million
00:40years ago.
00:41So what gives?
00:42Apparently, potassium feldspar.
00:44Researchers looked at evidence from all known extinction events over the last 600 million
00:48years, finding that if a meteor hit an area rich in potassium feldspar, an extinction
00:52event would occur.
00:54Potassium feldspar can be found in about 60% of Earth's crust.
00:57But when aerosolized into the atmosphere, it can drastically change the way clouds are
01:01formed, and in turn, Earth's atmosphere in general.