What would happen if an astoroid the size of the earth hit earth?

Answer 1

corner pocket...game over...

Answer 2

A large planetoid did strike the Earth about 4.45 billion years ago (in our world's relative infancy) and displaced the mass that created our moon (the moon's geology is made up of light elements found in the Earth's crust.

At some point in time a large planetoid apparently whacked Uranus as well, accounting for the odd rotation as well as unusual chemical signatures of that planet.

Answer 3

There are no asteroids the size of the Earth in the solar system. The largest asteroid in the asteroid belt is Ceres, about the size of New York State.

Answer 4

Assuming that the speed at impact was 40 km/sec, the impact energy would be equal to the sun's total output during 150 days. Or, to put it another way, the impact energy would be equal to the conversion of 5.34E+16 kilograms of matter to energy.

Let's suppose that half of this energy takes the form of radiation released during the five minutes following first contact. The fireball will be, during this time, an average of 21000 times brighter than the sun, meaning that our solar system would briefly have an absolute magnitude of -6.05, which is 10.8 magnitudes brighter than its usual magnitude of +4.75.

Answer 5

Please click the links below it has some of the answers:

http://curious.astro.cornell.edu/question.php?number=146

and

http://wiki.answers.com/Q/What_would_happen_if_the_earth_was_hit_by_an_asteroid
Depends on the size, speed, and composition of the asteroid. It could burn up in our atmosphere. It could hit the ground harmlessly as a small grain of sand. It could explode in the lower atmosphere and level thousands of square miles of forest. It could hit the ocean and cause a massive tsunami. It could leave an impact crater the size of Texas and throw enough debris into the atmosphere to start a very long "nuclear winter". It could slipt the earth in two.

and

http://www.astronomycafe.net/qadir/q975.html
and
http://www.madsci.org/posts/archives/2001-10/1003750250.As.r.html

Answer 6

Presumably a large population of the earth would be wiped out.

Answer 7

***WIPEOUT***

This would be massive enough to destroy the planet.

Happily there are no asteroids the size of Earth - anything this big is called a planet and orbits the Sun in predictable patterns the same as we do.

Answer 8

itd be catastropic check out this movie . one the size of texas heads for earth. there 2 or 3 others. they call them planet killers

Answer 9

We would shoot nuclear bombs at it and then we would all die by some scientific error, the fallout would be much more devastating then just one big rock hitting the earth.

Answer 10

Hello, goodbye. The end of earth.

Answer 11

Well not only would everyone be dead but whatever would be left of the planet would be knocked out of orbit and float away into deep space