What would happen if an asteroid hit the earth?

An asteroid that big traveling at that speed has the energy roughly equal to a 1 million megaton bomb. It's very likely that an asteroid like this would wipe out most of the life on the planet. A rendering of an asteroid colliding with Earth. read more

For an asteroid 10 km in diameter, it doesn't matter where it hits, ocean or dry land. Remember that the depest point in the read more

In 2028, the asteroid 1997XF11 will come extremely close to Earth but will miss the planet. If something were to change and it did hit Earth, what you would have is a mile-wide asteroid striking the planet's surface at about 30,000 mph. read more