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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.

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But what is the median atmospheric entry flight path angle? Many impacts would be a lot shallower than a vertical entry, and thus stay aloft longer. (And, fwiw, atmospheric entry is traditionally considered to start above the Karman line.)

Average impact angle is 45°. Travel time is thus √2, which makes little meaningful difference to impacting the surface. If you want to (pedantically) argue for EI at 122 km, fine; add a second to the travel time.

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.

To be clear, I don't spend any time worrying about something smashing into us. (There's lots of other things to be worried about.) I just don't want you to think that we'd have any time to watch the thing enter the atmosphere, because we wouldn't.

Also, the last time I posted a pic of a burning skeleton on Bluesky that came from popular media (Uncle Owen and Aunt Beru) it was hidden as mature content. I wonder how long this post will last.

Depends on the angle though, right? I remember the footage of the Chelyabinsk meteor, which you definitely could have seen coming if you happened to look in the right direction (not heard though obviously).

At the point of impact, yes, but further away the effects would be different. On the opposite side of the world, they would have some more time to figure out what's going on, depending on the size of the impactor.

Ever since Chelyabinsk I've always been terrified of seeing a streak like that across the sky and knowing I've only got about 2 seconds to hope it's small and going to airburst way up 😩 It's still kind of crazy that happened