What strikes me the most, is how fast the shockwave is moving. It takes about 6 minutes for the shockwave to pass through Europe.
So if I saw the collision on the news, I would be able to go on a cliff and watch the shockwave travelling towards me, knowing that within seconds I will be dead and minutes later all life on Earth will be dead.
Earth in the end has a surface temperature of more than 4,000oC.
(This simulation was created with a game-simulator; I know many other elements of this "game" are realistic, but can't tell how accurate this particular simulation is.)
Assuming same sized object, moving at a more "reasonable" speed (e.g. 50km/s):
- What will the actual effects of such a collision be (shockwave, temperature, oceans vaporizing, dust, etc)?
- Would the shockwave be able to kill me if I were in Europe and the object hit US?
- How fast would the shockwave travel and how much time would it take to engulf a country like Iceland?
- For how long will I be able to watch the shockwave from a 500m high cliff before it reaches me (assuming it will reach me)?