We're long overdue for extinction..
NASA: “Every day, Earth is bombarded with more than 100 tons of dust and sand-sized particles. About once a year, an automobile-sized asteroid hits Earth's atmosphere, creates an impressive fireball, and burns up before reaching the surface. Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the area. Only once every few million years, an object large enough to threaten Earth's civilisation comes along.
Asteroids with a 1 km (0.62 mi) diameter strike Earth every 500,000 years on average. Large collisions – with 5 km (3 mi) objects – happen approximately once every twenty million years.
The last known impact of an object of 10 km (6 mi) or more in diameter was at the Cretaceous–Paleogene extinction event 66 million years ago.
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