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Reminder: The *average* bolide impact velocity at Earth is 20 km/s. That's five seconds from the Kármán line to the ground. There's no slow movement of an asteroid through the sky, giving you enough time to say goodbye to your loved ones. One moment you're alive, the next you're on fire.

That's the *average* speed. Some impactors will be slower, others faster. Comets are probably going to be faster than asteroids. For a sufficiently high speed, the lithosphere will become molten.