When the earth is hit by a large enough asteroid, will it explode immediately?
If an asteroid strikes Earth, it will be a really, really bad day no matter how big it is. If the asteroid is a mile in diameter, it’s likely to wipe out life on the planet. Let’s hope that doesn’t happen anytime soon! If its a mile or larger in diameter it will wipe out all life on earth as we know it. It will seem to have an explosion effect since the power that will given off by this mamoth slam will be like someone setting off 10 million hydorgen bombs, and since this asteriod is traveling at about 30,000mph, i think its safe to say that in a blink of an eye, you will be dead even if you are 200 miles away since it will explode as soon as it makes contact. This site goes into all the details.