cross-posted from: https://lemmy.world/post/48430055
Only a tiny fraction of it probably melted. The atmosphere is really thin when you're moving at the velocity that cover seemingly achieved. Raw iron meteors that are much smaller, and moving significantly slower than that steel plate routinely reach the ground intact.
That's a real use of a time machine. Go back with ultra high speed film and camera so we can catch more than one frame of the thing and determine if it hit escape velocity of the solar system, or if it may be coming back to us in a few hundred thousand years.