PDA

View Full Version : Hw big would an asteroid have to be to destroy all lifeforms



Heroin
2004-Jan-21, 01:20 AM
How big does an asteroid have to be to destroy the earth? And how likely is that going to happen.

Sparks
2004-Jan-21, 01:42 AM
How big does an asteroid have to be to destroy the earth?
Very big.


And how likely is that going to happen.
*points to the moon*
Already did.

tuffel999
2004-Jan-21, 02:48 AM
13

AGN Fuel
2004-Jan-21, 02:52 AM
13

OK, I'll bite..... 13?

semi-sentient
2004-Jan-21, 02:58 AM
^^^ Heh, I was about to ask the same thing.

postCount++

tuffel999
2004-Jan-21, 02:58 AM
Number of times this has been answered.

AGN Fuel
2004-Jan-21, 03:08 AM
Number of times this has been answered.

Ahh, I see.

Ian Goddard
2004-Jan-21, 03:50 AM
Hw big would an asteroid have to be to destroy all lifeforms
This may not be a perfect answer, but according to Charles Cockell: "Perhaps, just under four billion years ago, the Earth could have been hit by asteroids up to 400 kilometers across, forty times bigger than the one that is supposed to have been responsible for the K/T extinctions. Such an asteroid would boil away the oceans and transform the atmosphere into one of steam and molten rock." The resulting temperatures would be "well beyond the upper limit for life and the surface of the Earth would have been baked free of living microbes."

Source: Cockell, Charles S. Impossible Extinction. Cambridge: Cambridge UP, 2003: 88.

Kaptain K
2004-Jan-21, 10:46 AM
Was this before or after the Mars sized one that gave us the Moon?

ZaphodBeeblebrox
2004-Jan-21, 12:17 PM
Was this before or after the Mars sized one that gave us the Moon?

During