Doomsday comet may hit Mars

[clive bradbury]

If an object of similar size ever hits earth, it won't do too much damage. After all, most intelligent life here has already been and gone...

[Jimbuna]

Originally Posted by clive bradbury

If an object of similar size ever hits earth, it won't do too much damage. After all, most intelligent life here has already been and gone...

Well, to be fair, has it ever existed in Stoke?

[GT182]

Oberon, what if by chance it knocks Mars out of it's orbit? 310 mlles across is one hell of a big piece of rock. And Mars isn't as large as Earth.

[Raptor1]

Originally Posted by GT182

Oberon, what if by chance it knocks Mars out of it's orbit? 310 mlles across is one hell of a big piece of rock. And Mars isn't as large as Earth.

I don't know if the mass of that comet is known, but if I'm not mistaken accelerating Mars enough to achieve Solar escape velocity or decelerating it to the point it will de-orbit into the sun will require orders of magnitude more kinetic energy than 20 petatons.

[Oberon]

Originally Posted by GT182

Oberon, what if by chance it knocks Mars out of it's orbit? 310 mlles across is one hell of a big piece of rock. And Mars isn't as large as Earth.

AFAIK the size of the comet hasn't actually been determined yet, so I'm not sure where you got 310 miles from, unless you mean the crater, which is not the same size as the impactor. A comet 310 miles wide coming in with the same speed of the comet in question would make a crater that is (quick calculations on impact website) a thousand miles across, but would probably still not do anything to Mars other than perhaps change the rotation speed by an infinitesimal amount, so a Martian day might go from being 24 hours 37 minutes to 24 hours 41 minutes. The tilt of the planet might alter a bit too, it's not particularly hard to alter axial tilts of planets, Earths has moved a couple of times recently, usually because of major earthquakes, the effects of such small shifts are usually pretty minor, if there are any at all.

No, this comet will create a large hole, a big fireball, a large shockwave and a massive debris cloud which will make things a bit dark underneath it for a while, but Mars itself will keep on spinning, just as Earth has kept on spinning despite being hit by objects potentially bigger than that comet.

Another thing to remember, that although the chances of an impact event on Mars are at 1 in 1250 (using the Monte-Carlo method), the current path of the comet puts it passing Mars further away than the recent Asteroid that shot underneath our comms satellites.

So, it's one to watch, but it's 50/50 whether it'll actually impact or not, and if it does miss then there's still a chance of an impact further down the line depending on the orbital cycle of the comet. It could be a sight for our childrens childrens childrens....providing a more nearby comet or asteroid hasn't landed on US by then.