[Telepathic Intruder]

The average density for an asteroid is 2g per cc. That gives it a total mass of about 536 million kg. You can expect an impact velocity of around 30-40 km per second. That gives it an energy anywhere between 57 and 102 megatons of TNT. Big, but not earth-shattering. Not an extinction event.

[DouglasKC]

The average density for an asteroid is 2g per cc. That gives it a total mass of about 536 million kg. You can expect an impact velocity of around 30-40 km per second. That gives it an energy anywhere between 57 and 102 megatons of TNT. Big, but not earth-shattering. Not an extinction event.

Unless it lands on ya....