Asteroid Sterilization: Size and Impact on Earth

[witze]

Killer Asteroid

Does anyone have any guesses on how big an asteroid would have to be to STERILIZE the earth?

 

[gorve]

the size would probably differ depending on where it lands if it was two big it would destroy the Earth to keep it intact probably large enough to wipe out the seas so a lot bigger than mount everist

 

[threadmark]

For an asteroid to destroy all plants and animals doesn’t have to be big at all. Its density would be the main factor in the final crunch. Depending on how dens and how much contacts the Earth's surface on impact. If you had an asteroid made of iron, a football field sized asteroid would probably do it.
TM

 

[mrspeedybob]

For an asteroid to destroy all plants and animals doesn’t have to be big at all. Its density would be the main factor in the final crunch. Depending on how dens and how much contacts the Earth's surface on impact. If you had an asteroid made of iron, a football field sized asteroid would probably do it.
TM

Yes but to sterilize the Earth implies killing all microbial life as well, I think that is a taller order.

I think kinetic energy would be the defining factor, not size. A Lumbering, slow moving rock the size of the moon may leave some of the heartiest microbes alive. However, a small car traveling at 99.999% of the speed of light would probably transfer enough energy to disintegrate the whole planet. Nothing would survive that.

 

[Drakkith]

However, a small car traveling at 99.999% of the speed of light would probably transfer enough energy to disintegrate the whole planet. Nothing would survive that.

Now THAT would be the way to go...getting hit by a volkswagon at near the speed of light. I think I'd be proud.