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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."
people used to think having a huge Moon like ours was a once-in-a-universe event.
And I should hope that they still think so, seeing as Mars does not have a huge Moon like ours... Despite evidence of an impact that COULD have created one, and yet didn't.
I reckon ther's not sucha a thing as a once-in-a-universe event!
Dawkins Revisited: A person is shit's way of making more shit -- Steve Barnett, anthropologist.
What is the evidence pro and con that Mars and Earth are the ones that actually collided, creating the Moon, and then they went spinning away from each other to settle in their current orbits.
Or maybe something big hit an earth which was bigger at the time and made three big pieces, Mars, Moon and Earth.
The composition of the three bodies are quite different so maybe that speaks against the possibility....
@de_machina
Sorry. Sorry. I had to do it. I'll just shut up now and go to work.
Faster! Faster! Faster would be better!
An impact in that scale would have surely destroyed the entire planet.
Web2.0: I love when people Flickr my cuil and digg my boingboing until my google is reddit and I start to yahoo
i understand why tidal pools can be thought of as interesting chemical incubators for life with all of the heating and cooling, wetting and drying that goes on, but a lot of other completely common and normal processes that can take place on a moonless planet can also lead to such incubators as well. waves, daily temperature variations, seasonal fluctuations, geography, etc.
the moon does make us an interesting little quasi double planet system. but i think that that uniqueness does not go hand in hand with our planet's other unique trait, life. correlation is not causation looms large in my mind on this idea that the moon gave the earth life. no, the earth's chemical makeup, temperature, and atmospheric pressure putting us near water's triple point, with a lot of water around: that gave us life. every other detail seems secondary and not mandatory
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Having a single big moon is supposed to be ultra rare? I'm really curious why that is. Given what we know of our solar system, moons are far from rare. We may only have one example of a large unitary moon, but come on, that's out of a sample size of 9 (8 now I guess) from a universe with presumably a nearly limitless number of planetoids. The argument almost strikes me as one of those arguments for Humans being the only intelligent species in the entire universe because it must be almost impossible for life to occur. Arguments that are grounded entirely in conjecture.
I read the internet for the articles.
I was under the impression that the importance of the moon was linked to the fact that it causes our planet to have cyclical seasons; namely the gravitational pull of the moon helps keep the poles more-or-less stable as opposed to having a more exaggerated wobble. This was from The History Channel's show "The Universe" so take it with a grain a salt...they end up talking about some wacky things on that show sometimes :)
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. [Un]fortunately, most of the debris in the Sol system has been cleared out by the current set of planets, so most of this stuff will remain speculation because the evidence is gone by now.
I feel more educated now.
Dewey, what part of this looks like authorities should be involved?
Agreed on that. Life evolved here with a moon over eons. Commenting on the uniqueness of having a moon sounds to me like "how lucky I, Mr. Puddle, am to live in a hole that fits my exact shape!"
If there were no moon it would have happened differently.
Four billion years ago!? God created the earth 6,000 years ago, so clearly this science is flawed. Heretics!!!
Note: Joke. (Sometimes it is hard to tell...)
And to think I once dismissed Immanuel Velikovsky as a crank of the first order, as ignorant of science as he was of biblical history. Boy, do I feel stupid now.
We can expect the heavens to rain manna from Mars upon us at any time.
So that is what killed off the martians? or the dino-martians?
I believe the moon's presence serves as a sort of shield from meteorites and asteroids. Also, the tidal forces the moon causes on Earth's core must create a lot of friction, keeping the core hotter over a longer period of time. While I do not believe the moon is necessary for life to have formed here on Earth, I believe the Earth would be much more primitive than it is today if we had no moon.
FOXTROT UNIFORM CHARLIE KILO
people used to think having a huge Moon like ours was a once-in-a-universe event.
No. "This has all happened before and this will all happen again."
I read about the simulations but they seem too dependent on everything happening so perfectly. A few more mega joules and you slag the planet, and a few less and you don't get the effect. At that scale the odds of that exact event happening don't seem very good. The simulations merely prove that it's possible - I just don't think it's particularly feasible.
Web2.0: I love when people Flickr my cuil and digg my boingboing until my google is reddit and I start to yahoo
There are several things that our extremely large moon does for us that make life much more comfortable.
#1 is of course tides that are more extreme than the sun could generate
#2 rotational speed. The moon has kept our rotation from slowing as much as it should have. Shorter day/night cycles are important for environmental management.
#3 atmosphere. The moon helped reduce the density of proto-earth's atmosphere. Without it we probably would resemble Venus.
#4 plate tectonics. The tidal influence on the crust heats up the mantel and keeps the plates from sealing
#5 protection. The moon intercepts a large percentage of the impacts destined for earth. This reduces the disruptions caused my meteor impacts. This was more pronounced earlier, when the moon was closer and when it was even more important (more meteors around)
#6 increased metal content. Since the moon is almost entirely light minerals, most of the metals that were in the original impact were left on earth which artificially increased the concentration of metal in the crust.
While I can think of other things that could help with one or two of these, I can't think of something that would satisfy all of these consistently for a few billion years.
What do you suggest as an alternative?
It is the same guy who predicted the 1993 mid-west floods to be once-in-500-year event.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
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?
Here will be an old abusing of God's patience and the king's English.
Mars Had an Ancient Impact Like Earth
No it didn't. Like Earth, Mars had an ancient impact, but the impact itself was decidedly NOT like the impact Earth experienced.
Earth's impact obliterated the Mars-sized object that impacted earth, leaving a ring of ejects circling the Earth. The ring coalesced into the moon. This didn't happen on Mars; Mars has no giant satellite, only two small moons.
Also, I saw a few different accounts, and not everyone is yet convinced that the disparity between Mars' poles was caused by a giant impact. The San Fransisco Chrinicle, for instance, says "Huge impact may have divided Mars surface".
An interesting, yet probably non-answerable question occurred to me - If an object did smash into Mars, rather than hitting pole-on as the theory says (and I'm no astrophysicist and can't even spell it properly), which seems improbable to mee, seeing as how all the orbits of all the crap circling the sun seem to lie on a plane, could it have struck Mars' pole and then hit the next planet in (Earth), causing its moon?If this could have happened, could life have been on Mars at he time but completely wiped out, with its remnant chemicals starting life over on Earth?
There have been meteorites that are Martians.
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
So planetary destruction isn't guaranteed, though 10^29 Joules is an incomprehensible amount of energy. Saying it was 100 billion gigatons of TNT might as well be "a gazillion tons" ... though I wonder if that's a metric ton or an imperial ton.
It is Imperial.
I'm a virgo and on Slashdot. Coincidence? Yes.
at the end of the formation of the four terrestrial planets.
Hot, fast, fat food and ditto planetary collisions.
This supposed event sounds like one hell of a show, if you would have been around for the whole act.
Eight Ball in the corner pocket.
"Kill 'em all and let Root sort 'em out"
Someone actually spoke of a beowolf cluster without making a joke!
I hope I've remedied this...
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
If there were no moon it would have happened differently.
There is no proof or even indication that it would or wouldn't have happened at all. Life must be pretty damned special* because we've found no indication of it elsewhere. We've had probes to most of our star's planets and not found any hint of life anywhere yet, we've had SETI running for a long time and no indication at all that there's anybody out there.
We don't even know how life started on earth. So far, we DO know that life is unique to Earth in our solar system. I don't think it's likely, but it is possible, no matter how improbable, that this little rock is the only repository of life in the universe.
-mcgrew
*Marvin says life rode the short bus to school.
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
I mean, Mars is a lot closer to the vacuum cleaner planets. Jupiter is like a Hoover, Saturn like a Dyson and Neptune is one of those water vacuums you see on late night TV. That's why Uranus is lying on its side, its falling asleep watching Neptune.
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!
You just got troll'd!
10^29 Joules is about 4 minutes worth of the total energy output of the sun.
If this is true (a glancing blow by a huge object), I'm confused as to where the debris ejected from the collision would have ended up? Certainly not everything would have ended up melding with the main planet, especially (again) if this was a glancing blow. I'd expect some sizable amount of mass to be blown into orbit, as happened in the Earth-Moon formation event.
Mars's two moons are incredibly tiny - IIRC more like smallish asteroids - so no coalescence of debris into a larger satellite as we have.
Someone more awake in astrophysics class maybe can help with this.
You're not trying to determine if something is likely to happen, just what DID happen. Unlikely or not, you have a low area with no rim. Saying that's unlikely doesn't mean it didn't happen.
The development of life on the planet Earth is an extremely unlikely event - but it HAPPENED. After the fact, the probability of any event happening is always 1.
Maybe the impacts were caused by projectiles sent from Klendathu?
What if the Earth and Mars collided with each other billions of years ago ?
Wanna fight ? Bend over, stick your head up your ass, and fight for air.
Helles, Isidis, and Argyre, the other large impact basins on Mars, though orders of magnitude smaller don't have rims, just big holes blown out of the ground.
horror vacui
Have you checked uranus?
Lately?
(Sorry... had to do it too. can't have a discussion about planets without discussing uranus)
Maybe it's not life as such but life *with legs* that may have come about due to tidal forces.
Hey you guys, this is a theory, not a fact.
Duplicated!
"A related article over at SpaceFlightNow [spaceflightnow.com] indicates that the researchers were specifically looking for a scenario that wouldn't vaporize Mars."
Well lucky for them they weren't looking for evidence of a scenario that _did_ vaporize Mars!
This Space Intentionally Left Blank
So the sumerians were right, after all !
I'm sticking to my belief that the core of the planet blew out through Olympus Mons. Just the mental image of the planet squirting out magma like a massive pimple is too cool to give up.
Having to work for a living is the root of all evil.
The existing 2 moons of Mars are likely to be captured asteroids from the asteroid belt?
If each mistake being made is a new one, then progress is being made.
I know slashdot has jumped the shark when the 'news' they publish is after the print media has it. I can't recall ever reading something in the morning paper before slash has something one it, but here it is. No wonder it seems I'm reading /. less and less these days.
-- John
Where's the picture of the crater?
The moon keeps the core of our planet from turning into a brick like Mars. It keeps the internal forces churning to keep it molten, keep volcano's active and to keep the gases coming out of the rocks and into the atmosphere.
Which is why we should make a big moon on Mar's to terraform it.
Find out in the next episode of Desperate Planets!
Feh, if I'm going to watch something like that, I'm going to wait for the racier Swingsystem.
The enemies of Democracy are
"Will Charon leave Pluto for a real planet?"
Crap, that's what I should have said instead :-(
You just got troll'd!
You know what they say about planets with big moons...
(Wink-wink, nudge-nudge)
Precisely. This giant impact idea has been around for more than 20 years (Wilhelms, D. E. and Squyres, S. W., 1984, Nature 309, p. 138-140). But they hadn't actually done the calculations, and many (myself included) assumed that any sufficiently large impact would have at least melted enough of the planet to erase any trace of the impact. These new studies show that such an impact model could in fact be responsible for the hemispheric dichotomy. Of course, while they show that it's possible, that doesn't necessarily mean that's what happened.
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Industrial Age 2 + How-to Stop Malignant Cancers.
People really think our moon was formed from debris from our earth after being hit by an asteroid? That doesn't work on SO MANY levels.
First off, I don't care how hard that astroid hit, it's not sending stuff into space. If the entire earth was made out of TNT and you set it off, the gravity would pull everything right back together again (this is true according to Dr. Melvin A. Cook).
Second, it would seem that from an analysis of the composition of the moon and the composition of the earth, that they really aren't made out of the same stuff.
or else!