Mimas and a Terran what if?

[Philippe]

So, I guess most of you have seen the picture of Mimas with its, comparatively, huge crater.

http://www.universetoday.com/am/publish/mimas_herschel_crater.html

Now would the Earth be able to withstand an impact large enough to create a crater that would represent 33% of it's diameter?

Obviously would wipe out most of life on Earth, but would the planet survive or crack?

Would we end-up with a second moon since the one we have now was created by a similar event?

[Doodler]

Given that Mimas is still intact, its a safe bet the planet could take the hit. I believe calling a similar event on Earth an extinction level event would be something of a mild understatement. It goes above and beyond simple climate change and into the question of whether the make up of the atmosphere itself won't permanently change. No matter where it hits, you're going to have a great deal of boil off of the oceans, because there's almost nowhere I can think of that a land hit would not be partially exposed to the oceans. The depth of the impact would punch through the crust of this planet like rice paper at the point of impact. Whatever would hit us with enough force to disturb 5.48 million square miles (Estimated crater diameter of 2642 miles) of the Earth's surface, is going to be digging deep. There would have to be some level of sympathetic activity from seismically active areas within range of the disruption.

I couldn't even imagine how big an impactor would have to be to cause a crater that big.

[Avatar28]

Ceres maybe?

[Inferno]

Obviously would wipe out most of life on Earth, but would the planet survive or crack?


Perhaps it could split apart but then rejoin together as other moons seem to have done.

[Kaptain K]

One big difference between Earth and Mimas is that Mimas has cooled to the point that it is solid clear through, but Earth has a molten outer core and a plastic mantle. An impact large enough to create a proportionally sized crater would also impart enough energy to liquify the mantle in the vicinity. The rock would flow back into the wound and (eventually) new crust would form over the area.

Such an impact would probably be a 100% extintion level event!

[um3k]

One big difference between Earth and Mimas is that Mimas has cooled to the point that it is solid clear through, but Earth has a molten outer core and a plastic mantle. An impact large enough to create a proportionally sized crater would also impart enough energy to liquify the mantle in the vicinity. The rock would flow back into the wound and (eventually) new crust would form over the area.

Such an impact would probably be a 100% extintion level event!
No, I think it'd be 99.999% extinction level event. Some bacteria would make it through, without a doubt.

[Kaptain K]

One big difference between Earth and Mimas is that Mimas has cooled to the point that it is solid clear through, but Earth has a molten outer core and a plastic mantle. An impact large enough to create a proportionally sized crater would also impart enough energy to liquify the mantle in the vicinity. The rock would flow back into the wound and (eventually) new crust would form over the area.

Such an impact would probably be a 100% extintion level event!
No, I think it'd be 99.999% extinction level event. Some bacteria would make it through, without a doubt.
Please note the qualifier!

"Such an impact would probably be a 100% extintion level event!"

[um3k]

One big difference between Earth and Mimas is that Mimas has cooled to the point that it is solid clear through, but Earth has a molten outer core and a plastic mantle. An impact large enough to create a proportionally sized crater would also impart enough energy to liquify the mantle in the vicinity. The rock would flow back into the wound and (eventually) new crust would form over the area.

Such an impact would probably be a 100% extintion level event!
No, I think it'd be 99.999% extinction level event. Some bacteria would make it through, without a doubt.
Please note the qualifier!

"Such an impact would probably be a 100% extintion level event!"
Qualifier noted. But I think "probably 100%" and "99.999%" mean two different things.