Mars Had an Ancient Impact Like Earth

quixote9 writes "The BBC reports on a set of Nature articles showing that Mars had an impact about four billion years ago by a huge asteroid. This was about the same time that a much bigger object slammed into the Earth, throwing material into orbit around our infant planet. This material is thought to have coalesced to form the Moon. 'It happened probably right at the end of the formation of the four terrestrial planets — Mercury, Venus, Earth and Mars,' said Craig Agnor, a co-author on the Francis Nimmo study. 'In terms of the process of the planets sweeping up the last bits of debris, this could have been one of the last big bits of debris.' There's a theory that having a big moon is important to the development of life, because the much bigger tides create a bigger intertidal zone, but people used to think having a huge Moon like ours was a once-in-a-universe event."

Comments

Re:Hopefully.

[Gewalt]

But perhaps it did, and the moon left orbit and is now known as Pluto.

Umm.

[ColdWetDog]

That's no asteroid....

Sorry. Sorry. I had to do it. I'll just shut up now and go to work.

Re:once-in-a-universe?

[Daimanta]

Well, except the creation and the end of the universe ;)

Re:once-in-a-universe?

[Mordok-DestroyerOfWo]

The gnab gib?

Re:Once in a universe?

[CarlosHawes]

Mars did have a large moon once like Earth. It was destroyed with the Illudium Q36 Explosive Space Modulator. It obstructed their view of Venus :)

"Billion Nagasaki bombs" as a value

[boyfaceddog]

From the article

According to one group of researchers, the rock struck with an energy equivalent to one million billion atomic bombs like the one dropped on Nagasaki in 1945.

I think after the first billion Nagasaki bombs, you just say "energy equivalent to being struck by the Moon".

Nit picking, I know, but how can you even wrap your mind around that number of atomic bombs?

Re:Orbital mechanics

[4D6963]

Unlikely. Pluto's orbit doesn't come close to intersecting with that of Mars, and circularizing a Pluto-sized object's orbit after the huge Mars collision event would require ... another huge collision event.

Or crossing Neptune very closely. And since we suspect that Triton was captured by Neptune as it was forming a couple with a similar body which got ejected away when Triton was captured, we can imagine that Mars' hypothetical Moon was that other body. Now who knows, Mars probably caught that asteroid that made this moon to protect its beloved Phaeton, who was ultimately destroyed by the mighty gravitational pull of the ruthless and jealous Jupiter who failed to capture Phaeton in the past despite his numerous attempts, and thus pulverized it to make Mars miserable in retaliation.

Meanwhile, in the solar system. Will Jupiter find out which of the other gas planets threw a Shoemaker-Levy 9 at him? What surprise lurks in the confines of the solar system for Mars' old moon? Are Pluto and Charon about to divorce? Find out in the next episode of Desperate Planets!