Maps Show Mars Was Once More Like Earth

vrioux writes "NASA scientists have discovered additional evidence that Mars once underwent plate tectonics, slow movement of the planet's crust, like the present-day Earth. A new map of Mars' magnetic field made by the Mars Global Surveyor spacecraft reveals a world whose history was shaped by great crustal plates being pulled apart or smashed together. ."

Comments

Breaking News!

[Anonymous Coward]

Earth not center of universe, other planets similar. News at 11!

Re:Breaking News!

[Anonymous Coward]

Earth not center of universe, other planets similar.

Similar is not the same thing as "alike". We're still grasping with whether the various effects we see on Earth exist on other planets. Even if we find that these effects are common, we're still left with a quandry about Earth itself. There are just so many little things about the Earth that are balanced in favor of life (e.g. Distance from Sun, size of star, size of planet/gravity, magnetic field strength, atmosphere composition, etc.), that it's statistically hard to say that there's life anywhere we'd be able to reach before we're long extinct.

Look up the Drake Equation for more info on why the Earth may very well be "the center of the Universe". (At least as far as life is concerned.

Re:Breaking News!

[SteveAyre]

that it's statistically hard to say that there's life anywhere we'd be able to reach before we're long extinct.

Similar life. :o)

Life would still have the potential to exist elsewhere, but would have to adapt to a different environment. As a result it could exist but would probably not resemble anything we've seen before... we may not even know it if we did find it.

Re:Breaking News!

[Anonymous Coward]

Life would still have the potential to exist elsewhere, but would have to adapt to a different environment.

This is a fairly common theory (especially in the wake of the early findings that the other planets in the Solar System are uninhabitable by humans), but our studies of our own solar system suggest it to be untrue. If life were as adaptable as suggested, then we'd find inflatable beings on Jupiter, Crystaline entities on Venus, creepy crawlers on Mars, and other life forms well suited to their environment.

Yet no such creatures have ever been found. Hope is still held that water creatures may be found on Jupiter's Icy Moons (specifically Europa), but we've pretty much exhausted the remainder of the Solar System.

Turning back inward toward Earth, we can't find life in many combinations. Pretty much all life on Earth follows the pattern of Carbon-basis with DNA information storage. About the most extreme variations are the circulatory systems of animals, with some having Copper-based blood.

Some organisms are able to survive extreme conditions, but they tend to not actually thrive in such environments. There are no signs of life that has specifically adapted to survive in conditions equating that of the more extreme planets. Even the Silicon-based Lifeform theory suffers heavily from a lack of any known examples.

While we occupy only an insignificant portion of the universe, our best evidence to date suggests that we may be far more alone than we might have hoped.

P.S. The Wikipedia article on The Fermi Paradox goes over many of these points in detail.

Re:Breaking News!

[peculiarmethod]

This is a fairly common theory (especially in the wake of the early findings that the other planets in the Solar System are uninhabitable by humans), but our studies of our own solar system suggest it to be untrue. If life were as adaptable as suggested, then we'd find inflatable beings on Jupiter, Crystaline entities on Venus, creepy crawlers on Mars, and other life forms well suited to their environment.

Yet no such creatures have ever been found. Hope is still held that water creatures may be found on Jupiter's Icy Moons (specifically Europa), but we've pretty much exhausted the remainder of the Solar System.


I'm going to have to argue with that. To be perfectly honest with ourselves, we can't say whether life only exists on a physical plane, or a mixture of magnetic, physical, spritual, gaseous.. we have no idea. It could be that life is abundant in forms we just haven't had the opportunity (capability) to discover yet. When one looks at areas that now seem unihabited, it seems impossible that they ever were. At present, desert covers a large part of Australia, The Great Sandy Desert, The Gibson Desert and the Great Victoria Desert combine to fill more than half of Western Australia. It was covered by large sheets of ice before that, and before that by a shallow ocean, which was most defintely teeming with life. The south pole has produced palm tree fossils. To a temporary observer (as we are to the celestial bodies), the south pole seems dead. it was once covered in life. Things change, things move, and accidents happen. Just because our sister and brother planets look devoid of life now, doesn't mean they are or have been. Or will be for that matter.

Re:Breaking News!

[VStrider]

There are just so many little things about the Earth that are balanced in favor of life (e.g. Distance from Sun, size of star, size of planet/gravity, magnetic field strength, atmosphere composition, etc.)

The distance from the sun, is not as important as it seems to be. The habitable zone has not been at 1AU at all times and it's going to change again in the future. There was a time when Mars was in the habitable zone and Earth was not. Similarly, when the sun will get older and on its way of becoming a red giant, Mars will again be in the habitable zone while Earth will be as hot as Venus.

The size of a planet and its gravity doesn't necessarily favor or hinder the development of life, as long as you don't take the extremes into account(ie. life would most likely not develop on an asteroid or a gas giant, though there could be exceptions). Mars is a small rocky planet with a gravity of 0.376 Gs which is quite low for humans. But that doesn't mean life didn't exist there. Earth's 1G is not some kind of universal standard for life. It's just the gravity, earth species live on. The same goes for atmospheric composition and magnetic field strenght. It's the enviroment we evolved and live in, not a universal standard. Humans would have as hard a time adapting to a lower/higher G enviroment, or to a deviant atmospheric composition, as a lifeform from somewhere else would have on Earth.

Also don't forget evolution. Life can adapt to a changing enviroment. If we send humans to live on Mars, after several generations, their successors won't be able to live on Earth's gravity. Which btw I think it's the key for colonization of other planets. If we ever find a way to accelerate evolution changes on ourselves, it'd be easier to do this instead of terraforming other planets.

Re:Breaking News!

[shawb]

Mars' atmosphere is drastically thinner than ours, and that is assumed to be in a large part due to the smaller size. The gravitational pull simply can't maintain a thick atmosphere, and Mars' size is such that the core has cooled off, and techtonic activity has stopped. Lack of techtonic activity means that atmospheric gasses are no longer being replenished. It may be possible that life could exist without an atmosphere, but it seems very unlikely to me. There would at least need to be a liquid medium to distribute metabolic chemicals (such as CO2 and O2 on earth) to allow for life to have the proper energy to survive. On Mars this would have to be on the surface, as the lack of techtonic activity means there would be no thermal vents such as on earth which provide another chemical gradient which allows some forms of life to survive. I don't have a problem seeing that life could have existed at one time on mars, but I highly doubt that it is currently there. There may be some remnant organisms in deep deep stasis which are basically waiting for favorable conditions to revive, but I personally do not call that currently living.

Re:Breaking News!

[MightyMartian]

This is a fairly common theory (especially in the wake of the early findings that the other planets in the Solar System are uninhabitable by humans), but our studies of our own solar system suggest it to be untrue. If life were as adaptable as suggested, then we'd find inflatable beings on Jupiter, Crystaline entities on Venus, creepy crawlers on Mars, and other life forms well suited to their environment. Yet no such creatures have ever been found. Hope is still held that water creatures may be found on Jupiter's Icy Moons (specifically Europa), but we've pretty much exhausted the remainder of the Solar System.

First of all, just because something can hypothetically exist, doesn't mean it will. I know of no biologist who thinks we should see 2010-like gas bag life forms around Jupiter, and I really don't see how that environment, as hostile as you're likely to find in the Solar System outside the atmosphere of the Sun, would ever support life. Beyond that, we haven't even really started looking. We've just put our toes in the water with sending some probes to land on Mars. The Jovian atmosphere is absolutely enormous, and though I doubt very much there's anything alive there, I'd wager it would take a very long time to eliminate the possibility. Evolution isn't a guarantee that every hypothetical kind of organism is going to exist. So I'm not sure where you get the idea that we should find these various critters on other planets.

Re:Breaking News!

[SteveAyre]

All are valid points.

I still think it's valid. We do see slight variations on Earth which at least show it's possible (you mentioned a few). The fact carbon-based life thrives so much here just shows a) they probably are all related in a very vague way and b) carbon-based life thrives in an Earth-type environment. The other chemistries supposedly don't work on Earth but would elsewhere.

Given the size of universe the fact we're alone in the solar system doesn't imply we're entirely alone at all, it just means our solar system is barren. I'm not saying life will occur everywhere, just that it can in a lot more place than we can survive.

And I did mention the possibility it could be so vastly different to us that we would not know if we found it given our observations would be based on it moving/communicating/eating in recognisable ways.

Re:Breaking News!

[uncoveror]

Of course Mars was once a lot like earth. Martians lived on the surface then, but are now underground. Not only have they built underground cities on their planet, they even built a base and a death ray on our moon!

Re:Breaking News!

[Xeriar]

Organisms on Earth have shown a rather intense ability to survive. I don't doubt that we may find microbes of some sort there.

That said, Mars will have retained most of its oxygen and nitrogen, it's just trapped in the soil and crust. Even Earth's moon could hold an atmosphere for a billion years or so.

The lack of water on Mars has more to do with its low gravity - hydrogen occasionally splits from water molecules, and it is very difficult for planets of less than Jupiter or so mass to keep a solid hold on them. Earth is losing water through this process as well, albeit at a much slower rate.

Comment removed

[account_deleted]

Comment removed based on user account deletion

probably more common than we think

[BushCheney08]

I wouldn't be surprised to find that the majority of solid planets that we examine undergo the same basic geologic mechanisms. Tectonics, subduction, spreading, etc, are probably far more common in the universe than we think.

Re:probably more common than we think

[BushCheney08]

I believe that's all that's needed. A molten core acts as a dynamo that generates the magnetic field, which is then recorded in the cooling rocks as alternating magnetic stripes. While that's going on, new rocks are created either through vulcanism or basalt spreading zones. It's been a while, but those are the basics I think.

Re:probably more common than we think

[frank378]

IIRC it's not just a molten core, but a spinning molten core made up mostly of iron which allows for a significant magnetic field to deflect solar winds.

I *think* I recall hearing that one of the reasons Mars could not "keep it together" the way the Earth did is because the core may have a different atomic/elemental makeup.

Any planetary scientists that can attest to/debunk this?

Re:probably more common than we think

[bitrodya]

Water generally helps plate tectonics along subduction zones by acting as a lubricant and lowering the melting point of the rocks involved. At least, that's what I think I remember from my geology class. So, maybe, no water, no tectonic activity?

Re:probably more common than we think

[buckhead_buddy]

The real reason? Inter-Global Warming.

Re:probably more common than we think

[J'raxis]

Tectonics might not be. One of the prevailing theories of why we have tectonic plates is that a sizeable chunk of the earth's crust got sheared off by a massive impact, leaving the remaining chunks of crust to slowly slide around the surface of the earth. The impactor that struck the earth hit at a particularly fortuitous angle; a little bit off and it would have destroyed the planet instead. Whether or not these kinds of impacts are improbable or not is still an open question -- one theory is that the impactor formed at one of the earth's Lagrange points, and it wasn't just a "random" blow from an asteroid, so it may be more common than it at first sounds.

Incidentally, the impactor blew that crustal material clear into orbit, which ultimately coalesced into the moon. See the giant impact theory entry on Wikipedia.

Re:probably more common than we think

[tommy_teardrop]

All solid planets already have evidence for most of these features. What has previously made the Earth unique is Plate Tectonics, a form of Global Tectonics. It allows the recycling of both the atmosphere and crustal rocks within an extended carbon cycle, which in turn produces much more complicated minerology. The Earth's surface is very young compared to most planets, both through constant erosion, and renewal from sea-floor spreading and high levels of volcanism.

Mars is nearly or completely dead, but it would be very interesting if it once had plate tectonics, because it tests either 1) the prediction that plate tectonics requires massive oceans (to lubricate subduction zones), or 2) the prediction that Mars never had a global ocean.

Re:probably more common than we think

[lotus_out_law]

Yes. Quite so.
Everywhere we hear about volcanoes in other planets..
Tectonic movement should be one of the primary suspects in all these cases.

kR.\'

Re:probably more common than we think

[ShibaInu]

I believe Io, Jupiter's moon is volcanic, but without tectonic plates.

Re:probably more common than we think

[Kupek]

My honest response is that I don't know, but using my limited knowledge, I can make a guess.

At the time of the impact, the Earth was very young. It didn't have an atmosphere yet. No atmosphere, no water. So, probably not.

Re:probably more common than we think

[J'raxis]

The other reply is probably correct; this was before water had precipitated out to form oceans and so on. Additionally, whatever got thrown up into orbit was hot: any water ejected would have certainly been vaporous. The material from which the moon is made -- part of the evidence that bolsters the Giant Impact theory -- appears to have literally boiled around the time of the moon's formation, which burnt off most of the lighter chemicals:

Chemical inspection of [moon] rocks found them to be nearly devoid of volatile and lighter elements, leading to the speculation that they formed from an unusually extreme amount of heating that boiled them off.

Re:probably more common than we think

[Xeriar]

Maybe, but the level of activity is somewhat in doubt. Earth's tectonics appear to be unusually active, thought to be a result from a collision of another planet orbitting at Earth's L4 lagrange point, shearing off much of the lighter portion of Earth's crust.

It is known that part of the reason why Mars is now 'dead' is because the planet ceased meaningful geological activity. The same is potentially true for Venus (though its rotation rate, for whatever reason, is abysmal.

Re:probably more common than we think

[kurtu5]

Actually the moon formation by impact theory says that the moon is composed of mantle matrial.

There is no evidence that there even was a crust prior to the impact according to the theory and if there was, it would have been thorougly molten and mixed with mantle material after the impact. Then after geologic ages, the lighter material in the mantle would have floated to the to of the mantle, cooled and became crust.

The heat generated by the impact could account for the energy required to drive mantle convection, but remember that its probably radioactive decay that keeps the mantle temperature fairly constant.

Also bear in mind that life has largely dictated the nature of the crust. With out an oxygenated atmosphere, the trace iron being convected from the core, would have not oxidized into light enough molcules to stay in the crust. So say some.

Re:probably more common than we think

[kurtu5]

Yeah, if there was an atmosphere and oceans prior to the impact, there wasn't any after.

The temperature at the surface of the newly coalesced earth and moon, would have been large enough for most if not all lighter gaseous elements to acheive escape velocity and quickly been blow away by the solar wind.

Re:probably more common than we think

[WalksOnDirt]

It has been speculated that Venus may undergo a complete crust turn over at long intervals rather than Earth's gradual spreading-center to subduction-zone process. If this is the norm among Earth sized planets that have NOT have had an early collision that stripped off much of the crust, it could be a reason for intelligent life being rare (as per the Fermi Paradox).

Re:probably more common than we think

[mfrank]

Or less common. Depends on the distribution of elements in the local region of space, I would imagine. Venus has a crust quite a bit thicker than Earth, and doesn't really have plate tectonics. Pressure just builds up until the planet melts down every hundred million years or so.

The collision 4 billion years ago of a Mars sized body with the proto-Earth resulted in the formation of the Moon, with Earth getting more than its fair share of the metal cores and the Moon getting more than its share of the rocky crust. If that hadn't happened, Earth would likely melt down like Venus every now and then and it would have been impossible for life to evolve here.

Re:probably more common than we think

[sl4shd0rk]

> I wouldn't be surprised to find that the
> majority of solid planets that we examine
> undergo the same basic geologic mechanisms.
> Tectonics, subduction, spreading

If not, we can always depend on good old-fashioned
plague, fear famine, chaos and decemation. If there's
one thing humans will be good at, anywhere in the
universe, it will be self demise.

Animation?

[brian0918]

Am I the only one for whom "click on image to start animation" seems to mean nothing?

Re:Animation?

[kevn]

You need to be a Spaceflight now premium subscriber to get the extra video content.

Re:Animation?

[se7en11]

Yes, it's just you. Try not to take in pers....err nevermind

Re:Animation?

[HaqDiesel]

It's one of those brand new animated JPEGs, you have to press ALT+F4 to see it

J/K LOLZ

Re:Animation?

[Anonymous Coward]

Plate tectonics takes millions of years. Be patient.

Re:Aliens?

[BushCheney08]

Seeing as how we do not behave exactly like every other animal...

Please tell me you're being facetious. I'm sure you'll find that no two types of animals behave *exactly* alike. However, a whole lot of them (including us), do exhibit many similar behaviours.

Re:So what happened?

[kyle90]

Probably the wars they fought over oil. That's why we won't find any there now. Come to think of it, someone should probably tell Bush that. I'm convinced that he's only pushing his space exploration mandate because he thinks there's WMDs on the moon and trillions of barrels of oil on Mars. (for those of you who are going to mod me down as a troll [and I know you're there], it's a JOKE. get a sense of HUMOUR)

Based on the site photos...

[Pomme de Terre!]

... it also appears to have been ruled by giant purple spiders.

Re:Based on the site photos...

[RobertB-DC]

Giant purple spiders aside, does the image show actual spots where the remnant magnetic flux is particularly strong? It seems like those spots might be an interesting place to site the first few Mars colonies.

Since shielding from the solar wind is a big issue, a location with just a little help from the residual field (even if weak) might have some advantages over a spot with no help at all from the dead crust.

Re:Based on the site photos...

[meringuoid]

Giant purple spiders aside, does the image show actual spots where the remnant magnetic flux is particularly strong? It seems like those spots might be an interesting place to site the first few Mars colonies. Since shielding from the solar wind is a big issue, a location with just a little help from the residual field (even if weak) might have some advantages over a spot with no help at all from the dead crust.

It probably wouldn't help much. The local magnetic remnants would be tiny, not enough to significantly shield an area.

You'd plant your colonies where there are sites of scientific interest, or resources of value to the colonists, and put up with the radiation. One thing you won't be short of on Mars is rock. Lots and lots of rock. Dig a great big tunnel into the side of Mariner Valley, end of radiation problem...

Re:Based on the site photos...

[Hillgiant]

I, for one, welcome our new giant purple spider overlords.

Re:Aliens?

[meringuoid]

Seeing as how we do not behave exactly like every other animal, would there be a way that we could have come from Mars? Perhaps Adam and Eve were real and the first couple to come.

Rubbish. We came from the Pak homeworld.

In other words, no. We, as in humans, didn't come from Mars. We're definitely mammals, closely related to the other great apes. It's about as plain as you could ask for at every level from DNA right through to gross anatomy.

It is conceivable that life originated on Mars and spread to Earth in the days of nothing but single-celled organisms, but that's quite another matter.

Re:So what happened?

[LiquidCoooled]

[X] CowboyNeal.

Journal link

[brian0918]

Here's the journal abstract:

http://www.pnas.org/cgi/content/abstract/050746910 2v1

"Mars currently has no global magnetic field of internal origin but must have had one in the past, when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization). A new map of the magnetic field of Mars, compiled by using measurements acquired at an 400-km mapping altitude by the Mars Global Surveyor spacecraft, is presented here. The increased spatial resolution and sensitivity of this map provide new insight into the origin and evolution of the Mars crust. Variations in the crustal magnetic field appear in association with major faults, some previously identified in imagery and topography (Cerberus Rupes and Valles Marineris). Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and support the notion that the Mars crust formed during an early era of plate tectonics."

Re:So what happened?

[failure-man]

No, no. The martians never had oil. That's why it's a cold desert now.
 
Now Venus . . . . that place probably had a shit-ton of oil. Just look at that greenhouse effect!

No

[brian0918]

" Seeing as how we do not behave exactly like every other animal, would there be a way that we could have come from Mars? " It would be damn near impossible for humans and chimps to be so similar genetically. Species don't evolve toward eachother genetically.

Re:No

[aristotle-dude]

Are you sure about that? The "theory" goes that environment affects how a species evolves. It would seeem logical that two species places in the same environment, might develop similar characteristics.

But, why am I here explaining how the theory that you have "blind faith" in works?

Similar DNA structures does not prove anything. It is perfectly possible for species on different planets to have similar genetic patterns. In the same way, it is perfectly possible for geologically separate species to develop with similar characteristics.

We have no known extra terrestrial DNA to compare against to prove your assertion that DNA structures differ greatly through out the universe.

Re:No

[brian0918]

They will evolve similar appearances and superficial mechanisms to adapt to their environments, but not the same DNA. That's why certain snakes take on the appearance of poisonous snakes while being harmless. Unless an animal's natural predator has a built-in DNA scanner, there would be no motivation to move toward similar DNA.

I never asserted that DNA structures differ greatly througout the universe. I'm talking about evolution--that's how it works. Species' DNA become more different with time, regardless of how their appearance changes. You really need to take a few courses in evolution.

Re:No

[vertinox]

Species don't evolve toward eachother genetically.

I take it you haven't been to West Virginia. You know those stories about sheep farmers... Well... Let's say "it gets really lonely up on dem hills".

Re:No

[blincoln]

It is perfectly possible for species on different planets to have similar genetic patterns.

Maybe in the sense that it's perfectly possible for me to tunnel through a concrete wall like an electron. It's just that the amazingly low probability makes it not worth trying.

Unless you're arguing for panspermia, why are you even assuming that hypothetical life on other planets even uses DNA?

Re:No

[ceoyoyo]

From our observations of genetics on Earth, characteristics may well evolve independently (such as fish fins and whale fins) but the genes that code for those gross characteristics are different. The great apes and humans share 99% of their genetic code... to get that sort of genetic similarity independantly would be... highly unlikely.

If Mars was like Earth...

[Spy der Mann]

Does that mean the Earth will end up like Mars in the future?
And how will this data help us terraforming Mars?

Far from answering, I think this only leaves us with more questions asked.

Re:If Mars was like Earth...

[kesuki]

Does that mean the Earth will end up like Mars in the future?

probably, because the evidence is looking towards unfiltered radiation being a highly destructive force on atmospheric gasses, soncider the 'ozone hole' at the poles, the one 'weak point' of the earth's own magnetosphere. while other than a rapid destuction of the ozone layer, the radiation given off by a fusion reactor the size of the sun is quite likely not something species that evolved without exposure to hard radiation can survive. roaches and certain basic plants will be the most suited to survival in the event that the earth's crust cooled sufficiently to cause a break down in the magnetosphere. nocturnal underground dwelling species will also cope well. but a collapse of the earth's magnetosphere would make walking around in daylight hours most certainly a life threatening event. it would also disrupt communications, and electirical transmission and basically, unless your windows are certified to block both microwave and UV radiation, just sitting in a sunbeam could cook you in minutes. eventually, the sun's energy would simply boil all the water off the planet into space, so not even the hardy cockroach would see it's dominance last. the magnetosphere is what keeps our atmosphere and our planitary water safe, any long term loss of the magentosphere would spell doom for any species incapable fo crating entirely artifical ecosystems, say in space, or on 'unliveable' planets.

terraforming mars is a complex task, colonizing it is vastly simpler. technically, the moon could be colonized, it might have been colonized already if sufficent affordable space travel technology had been developed.

Re:If Mars was like Earth...

[Idealius]

I was going to mod this insightful, but then I decided to do some research about the facts.

"The climate-aerosol debacle: The U.N. science advisory group, the Intergovernmental Panel on Climate Change (IPCC), has a big credibility problem. Its 1996 report, the basis for Kyoto, had to admit that the rapid warming predicted by computer models was not occurring. So they hit on an explanation to account for the discrepancy: Sulfate aerosols, particles created from the burning of coal and other sulfur-containing substances, were supposed to reflect incident sunlight and create an offsetting cooling--forcing an agreement with the observations that show no warming trend. Unfortunately for the IPCC, the details don't match. The Southern Hemisphere, containing fewer aerosols, should be warming more rapidly-but it isn't."

by S. Fred Singer
Washington Times, January 10, 1999

http://www.sepp.org/glwarm/partinggreen.html
http://www.sepp.org/bios/singer/biosfs.html

But then again, lets take a look at what a certain third party has to say about his character:

http://www.ecosyn.us/adti/Singer-Nightline.html

I wish I had time to follow the trail further.. I leave you to your own conclusions. Maybe someone already knows, but with agendas flamebait is inevitable.. I look to someone with a very reliable source to clear this up.

Re:If Mars was like Earth...

[Xeriar]

Well yes, eventually Earth will freeze solid, or near enough so that tectonic activity no longer occurs.

This won't happen for a very long time. The sun will scorch Earth's atmosphere away and push its orbit back during expansion first. Being closer to the sun, several times more massive, having a moon and an overall denser crust (more appropriately, a smaller fraction of lighter materials, which make up our continents) mean that Earth will take a very long time to cool so.

Re:If Mars was like Earth...

[RetroGeek]

whining about global warming again

Global warming is a fact. The cause is yet to be determined.

And evidence suggests that the cause may be external to the earth, as it seems that Mars is getting warmer. How many SUV's have you seen on Mars lately?

Re:If Mars was like Earth...

[kurtu5]

You do know that the field shuts down and reverses every 250,000 years or so right? This means that homo sapiens sapiens would have been exposed to the environment your are talking about, around 16 times; 4MY/.25MY.

sayeth the great Wiki.

What I have always wondered, is how long is the duration of no field? Also, I think our biology has quite a few tools built in to deal with this exposure. I am sure that not all of us could handle it, but 10% should do just fine.

Re:If Mars was like Earth...

[kurtu5]

I doubt the earth will ever freeze solid. In the estimated 4BY to red giant stage for our sun, I think the planet will still have enought radioactives in the mantle to keep the interior warm. Once the sun's atmosphere expande to engulf the planet, it will heat up and start to boil away to vapor.

Of course, the earth could get freeze if it gets knocked out of its orbit and wanders interstellar space effectively forever.

Re:If Mars was like Earth...

[Xeriar]

It's been calculated that solar winds will push Earth's orbit back out of reach of the sun's photosphere.

Re:If Mars was like Earth...

[kurtu5]

Hey thats kinda cool. How much though? What source?

Re:If Mars was like Earth...

[Xeriar]

http://en.wikipedia.org/wiki/Sun#History_and_futur e_of_the_Sun

Not sure, I've read about it elsewhere though.

Re:If Mars was like Earth...

[kurtu5]

I do see your point, but his was more about cockroaches and less about erosion of the atmosphere due to the absence of the magnetopause, bow shock and all those other interesting field related entities.

Re:If Mars was like Earth...

[kurtu5]

Hmm. It doesn't mention solar wind pushing the earth. I think it refers to the reduction in mass of the sun and the resultant change in the major and minor orbital axis. Same result none the less.

Mars-Earth comparison offends Martians deeply

[digitaldc]

Martians are NOT amused by this comparison. They find it degrading, humiliating and defamatory.

"Earthlings have never come close to inventing a Illudium PU-36 Explosive Space Modulator, nor can the 19.7 km height of Mt. Everest even touch Olympus Mons with an altitude of 27 km!", says Mars local, Marvin.

Re:Mars-Earth comparison offends Martians deeply

[meringuoid]

"Earthlings have never come close to inventing a Illudium PU-36 Explosive Space Modulator, nor can the 19.7 km height of Mt. Everest even touch Olympus Mons with an altitude of 27 km!", says Mars local, Marvin.

Tch, tch, tch, tch... Nyeeeeeeeh. You got rabbits on Mars, Doc?

Re:Mars-Earth comparison offends Martians deeply

[nethneta]

Except that Mt. Everest is roughly 8.8km tall, not 19.7km. http://en.wikipedia.org/wiki/Everest http://en.wikipedia.org/wiki/Olympus_Mons

Re:Mars-Earth comparison offends Martians deeply

[nickbrown]

Olympus Mons is indeed 27km high, however Mount Everest is only just under 9km high, not 19km.

Re:Mars-Earth comparison offends Martians deeply

[D'Eyncourt]

Actually the original poster (digitaldc) is correct. Everest is 8.8 km above SEA LEVEL (which obviously cannot apply to Mars). To make a fair comparison with Olympus Mons you should ignore the water on earth and measure from its lowest point (the Mariana Trench, 10.9 km below sea level) and with this you get 19.7 km for Everest.

Liquid Cores

[deathCon4]

All planets (like our own) which have a dynamic liquid core have magnetic fields. The strength of the field depends on how large and dynamic the molten core of the planet remains. When planets form, they start as a liquid lava rock, and slowly cool over millions of years. As they cool, the outer crust (or mantle) solidifies, while the core remains molten. This is true of any solid planet (not gas giant) therefore any rock-type planet would most likely of had a magnetic field at one time. Mars unfortunately is far enough from the sun that it has cooled to great depth inside the planet, reducing its liquid core to a very small percent of its original size, reducing and almost eliminating its magnetic field, which is at present very weak. Another proof of this is the lack of volcanism on Mars, which by examining the topographic features was once very active.

Re:Liquid Cores

[phlegmofdiscontent]

The cooling of Mars's core has nothing to do with insolation. Planetary cores are molten (or not) due to the presence of radioactive elements which release heat as they decay. Mars is less dense than Earth, meaning it's core is much smaller and probably has a smaller proportion of uranium, etc than Earth. Thus, the amount of heat generated by radioactive decay dropped off much faster than here, thus ending most geological activity billions of years ago (not all of it, though, as there are indications of volcanic activity as recent as 100 million years ago which is a small fraction of Mars's lifetime). If solar influx had anything to do with tectonics, we would expect Mercury to be much more active than Earth, but it's not. It's about as dead as the Moon, geologically speaking.

Re:Liquid Cores

[Anonymous Coward]

Ummm radioactive decay = molton core? I don't think so. There's too little of that on our planet.
The reason we have a molton core while a planet like mars doesn't is gravity. The pressure created by gravity produces heat = molton core. Mars is a smaller planet with a lower mass = less pressure = less heat = small core.

Re:Liquid Cores

[Crilen007]

So does this mean we have to launch a bunch of nukes to jumpstart it?

Re:Liquid Cores

[digidave]

"there are indications of volcanic activity as recent as 100 million years ago"

Actually, there are indications of lava flows on Olympus Mons as recent as two million years ago.

Re:Liquid Cores

[phlegmofdiscontent]

At least some of the heat in the Earth's core is from radioactive decay.

http://www.newscientist.com/article.ns?id=mg187251 03.700

Additionally, planetary formation theories state that during the Earth's formation, it would have melted from the accretion impacts that created it. While pressure alone will melt the metal-silicate materials deep in the Earth, it won't create heat (melting actually costs energy, even if kept at constant temperature). Gravitational contraction will create heat, but the Earth hasn't contracted much in the past 4 billion years (gravitational contraction was a proposed mechanism for the Sun's output, but was shown to be insufficient). While my explanation was simplified and doesn't tell the whole story, it is mostly correct.

Re:Liquid Cores

[Shotgun]

All planets (like our own) which have a dynamic liquid core have magnetic fields.

All of 'em, huh? You think that maybe we might be going a little bit beyond what we know? Hmm?

Re:Liquid Cores

[Anonym1ty]

The cooling of Mars's core has nothing to do with insolation. Planetary cores are molten (or not) due to the presence of radioactive elements which release heat as they decay. Mars is less dense than Earth, meaning it's core is much smaller and probably has a smaller proportion of uranium, etc than Earth. Thus, the amount of heat generated by radioactive decay dropped off much faster than here, thus ending most geological activity billions of years ago (not all of it, though, as there are indications of volcanic activity as recent as 100 million years ago which is a small fraction of Mars's lifetime). If solar influx had anything to do with tectonics, we would expect Mercury to be much more active than Earth, but it's not. It's about as dead as the Moon, geologically speaking

Is it possible that the conditions here on Earth are caused specifically by the Moon? I mean tidal forces from our Moon ought to have something to do with why our core remains liquid, and why we have a magnetic dynamo. Is it possible that perhaps Mars at one time had a larger satellite it has since lost? Perhaps it is not a coincidence the only other places we think we have _seen_ volcanic activity also happen to be places where there are high tidal forces (like Io and Titan). -Understandable we do have evidence of past volcanic activity on both Mars and Venus and they do not have large moons {?anymore?}, but it does lead me to speculate. How much of that volcanism is due to cooling since creation and Atomic decay... how much could have been due to the constant churning of tidal forces? ---What would happen to Mars if it had a larger satellite? If it did and the insides melted and gasses were produced, what would happen to the Martian atmosphere? -Could Mars again have a magnetic field? (it's always fun to speculate).

Could it be possible to terraform Mars by giving it a sufficiently large satellite?

Re:Liquid Cores

[kurtu5]

I am making lots of replies in this interestig thread.

I used to think the radioactic heating was from core material, but the bulk of it is from mantle material: primarily from Th, U and K.

Of course, many have different opinions as to the distribution of the radioactives and the need to assume the abundances others have put forth. This is an interesting article to show some of those assumptions.

http://www.mantleplumes.org/Energetics.html

Re:Liquid Cores

[kurtu5]

Isn't the moon to far away to have a significant effect? Perhaps there is a butterfly effect, but the moon is no where near the Roche limit, where the bigger body want to rip the smaller boy into pieces due to tidal forces.

In fact it is the most unusual planet-moon system in the eintire solar system, most systems have Roch limits ranging from 4-1.5:1 whereas the earth-monn system is around 41:1 or 21:1 depending on which model you use.

Re:Liquid Cores

[Anonym1ty]

Isn't the moon to far away to have a significant effect? We don't want to rip the planets into pieces!!

Just because the Moon is far enough away not to be torn apart doesn't mean that it has little effect on Earth. It moves the oceans around. It raises and lowers the crust. It may even churn the core. You don't think the center of gravity of the Earth-Moon System moving around inside the Earth's mantel doesn't do much?

We don't need to be so close together to cause objects on the surface of planet to fly off due to tidal forces, Just enough to mix up the fluid parts. The oceans move due to tidal forces, why can't the liquid parts of the interior? -this is what they say is going on in Titan, Io and Europa. I don't see any of them flying apart.

Re:Liquid Cores

[kurtu5]

Yeah, I invoked the Roch limit to illustrate that the Jovian moons have one an order of magnitude lower than ours. So your comparison is IMHO an order of magnitude off= not really, but you see what i mean?

Re:Liquid Cores

[Anonym1ty]

No, I don't

Re:Aliens?

[eln]

I think it's far more likely we came from Golgafrincham. How else could we explain our penchant for sanitizing telephones?

Re:You know the third one was made of paper mache?

[Evan Meakyl]

>You know the third one was made of paper mache?

I didn't know this. But which one???

Re:Aliens?

[m50d]

Seeing as how we do not behave exactly like every other animal, would there be a way that we could have come from Mars?

We're incredibly similar to every other animal - same basic chemistry, most of our genome the same. We have the same ancestors as every other living thing on this rock. A better (and open) question is whether all life on Earth is descended from (primitive) life that originated on Mars and was carried here by meteorites before Mars became uninhabitable.

I never would have guessed....

[oliverthered]

... What with that huge fisher that opened up on Mars and all the volcano's, where did they think they came from if it wasn't plate tectonics.

Re:I never would have guessed....

[Gravedigger3]

Olympus Mons was a volcano formed by a hot spot. Thats the only way it could have gotten so big. If the plates had been in motion while it was forming it would be a chain of volcanos like Hawaii instead of one uber volcano.

Volcano's are not proof to plate tectonics because the presence of water is one of the key factors of creating magma under a subduction trench. The water reduces the melting temperature of the rock and causes it to melt in when it usually wouldn't. Most likely the Volcano's on mars are formed by hot spots..... that or there used to be oceans at one time.

Re:I never would have guessed....

[oliverthered]

But what about that huge fissure, it sure looks like a couple of plates ripped appart, kinda the opposite of the Tibetan plateau (did the same geological even create the Mariana trench?). The plate techtonics don't have to have lasted for that long or they could be incredibly slow (Mars doesn't have a large moon) creating one big volcano and a huge trench.

Re:I never would have guessed....

[kurtu5]

The mariana is a sbuduction zone.

perhhaps its a rift fault, we have several on earth. There are only two above water that I am aware of, the Afircan rift valley and part of iceland.

Re:I never would have guessed....

[palndrumm]

The other thing water does is change the composition of melt that comes off the plate when it gets subducted, so the rocks produced at a subduction zone (granites) are different to those produced at mid ocean ridges and hot spots (basalts). Granite has a lower density than basalt, which means that once produced it tends to hang around up at the surface during plate tectonic processes, where it gradually accumulates and forms the continents we have today, while the heavier basalts form the ocean basins. There doesn't seem to be the same differentiation between continental granites and oceanic basalts on Mars, which might indicate that there was never quite as much water around to aid the plate tectonics process.

Re:So what happened?

[ifwm]

"for those of you who are going to mod me down as a troll [and I know you're there], it's a JOKE. get a sense of HUMOUR"

It would probably be funny, if it hadn't been done a thousand times in a thousand ways while discussing a thousand different topics.

That, and the fact that it was just dumb.

Re:Aliens?

[SgtClueLs]

No no you guys have it all wrong. The Flying Spaghetti Monster reached down his noodley appendage and created a Mountain, Trees and a Midget. This ape business are lies spread by the non-FSM Believers. They shall never know what heaven is like, with it's stripper factory and beer volcano!

Re:Aliens?

[EtherealStrife]

bonobos share 99-99.6% of our genetic makeup. Chimpanzees share around 98.5%. It's kinda hard to encounter that similarity by pure chance...

If you aren't joking, you've got some facts to check (and school to attend). Begone, creationist troll!

.bak

[MaXiMiUS]

This is a perfect example of why you should always back up your work, too bad it would take up like, 65535TB of space to back up our entire planet.

Re:You know the third one was made of paper mache?

[Thud457]

No clarification here, but freakin' hilarious!

Martian Tectonics

[praedictus]

A pity the article didn't have an actual map available, it would have been interesting to see at what stage of crustal evolution the process stopped. For instance our continental masses are composed of smaller accreted terranes (the process is ongoing: W.California is being added to the N.American plate) ..

Re:Aliens?

[Carthag]

Well since we evolved from Pak & other animals on Earth/F124 evolved from mutated food yeast, that is obviously the reason that we behave differently.

Mars' orbit once crossed Earth's?

[Anonymous Coward]

I once read an interesting story about some astonomer who believed that a long time ago Mars' orbit once was highly eliptical and crossed Earth's orbit and there was a near collision. Mars used to have oceans that alternatively froze solid and melted & boiled during it's highly elliptical orbit around the Sun until a very close encounter with Earth, where the two planets' gravities caused them to do a quick dance around each other during the near-collision, slinging off most of Mars' water which then was captured by the Earth's gravity and eventually fell into our own oceans, then Mars itself got slung outward towards it's current orbit where it collided with another small planetoid, the collision resulting in the formation of the asteroid belt and Mars' current stable orbit that is vastly less eliptical that before, but still not "almost circular" like Earth's orbit..

Re:Mars' orbit once crossed Earth's?

[meringuoid]

That's quite a story.

What was it from? SF, or is someone serious about that idea? Because if they are serious, I can't imagine what kind of evidence they might present for it. At least with the Big Splash notion of lunar formation they can compare Moon rocks to those from Earth...

Re:Mars' orbit once crossed Earth's?

[Pfhorrest]

I've heard a different version of this same hypothesis. I don't recall where from, it was years ago, but whoever put it forth intended it seriously, not as fiction.

The notion that I heard was more closely related to the Big Splash you mention and less related to Mars. It held that another planetoid, not Mars, once held a highly eccentric orbit which crossed those of both Earth and Mars. It was this planetoid which collided with Earth and formed the moon, and the remnants of the broken planetoid eventually settled into orbits out past Mars to become the asteroid belt.

No idea how scientifically feasible this is, but that's the hypothesis as I heard it.

Re:Mars' orbit once crossed Earth's?

[bpowell423]

Google for "gulliver's travels mars". It will provide some interesting reading, if nothing else. Jonathan Swift described, with some degree of accuracy, the 2 moons of Mars long before anyone discovered them with telescopes. The explaination that I've heard is that the orbits of Earth and Mars used to cross, as the grand-parent poster referred to, and that humans had actually observered the 2 moons of Mars eons ago and passed the story on. Jonathan Swift supposedly heard about this and put it into his story. You can take it with a giant grain of salt, but it's interesting. If Mars showed up every couple of years, nearly filling the sky, and bringing meteor showers and earthquakes with it, I can see why early humans might have called in the God of War. There may be nothing to it, but it's interesting non-the-less.

Re:Mars' orbit once crossed Earth's?

[Insensitive_Claudio]

Yeah, google for "orbital resonance mars" while you are at it. Apparently the provovative notion is that Mars used to rise 50 times bigger than our moon. The resulting cataclysm is why all calendars moved from a 360 day year to a 365 day year in 701 BCE.

Re:Mars' orbit once crossed Earth's?

[MightyMartian]

That wasn't an astronomer, it was a quack named Velikovsky.

Re:Mars' orbit once crossed Earth's?

[kurtu5]

Ah yes, "Worlds in Collision", wwhat a great read. Until you start thinking, hey if the Earth reversed direction in less than a week, wouldn't the conservation of angular momentum literaly boiled the planet?

Re:You know the third one was made of paper mache?

[Mattcelt]

No, but the triple-breasted whore of Eroticon 6 might be...

Re:Aliens?

[Anonymous Coward]

Seeing as how we do not behave exactly like every other animal, would there be a way that we could have come from Mars?

Yes, but only men.

how can this be?

[minus_273]

was george bush around back then to destroy it? how else can this happen?

Re:Aliens?

[fitchmicah]

Yes, and how exactly is it necessary that life "came from Mars?" Did Earth have some shortage of qualifications for life to develop here? If you are going to say "it came from a Mars rock," please explain exactly how you know the rock is specifically from Mars, how it got off of Mars in the first place and happened to smack into a location on Earth at a time when by chance, the conditions on earth were somehow friendly to life adapted to a /completely different/ planet. Also, rocks don't just fall off of planets. No, the planets warp space so that the rocks are getting pushed outward by the normal force of matter in the planets. This is why we don't accidentally fly off of Earth and colonize life on Pluto. What's more, nobody /knows/ anything, so don't be so certain about this. I am not saying it's wrong, I am just saying that it's a hypothesis where people are gathering evidence for and against it. There probably isn't absolutely tons of evidence for any ideas about Mars, seeing how we haven't really been there that often and all we know is what we can see by analyzing the frequencies of electromagnetic radiation that is allowed to escape from the planet's surface. I can pretend I'm smart just like everyone else.

Re:Aliens?

[RichDice]

Seeing as how we do not behave exactly like every other animal, would there be a way that we could have come from Mars?

Perhaps Adam and Eve were real and the first couple to come.

We behave a lot more like the animals on Earth than we behave like all the animals we know of on Mars. (I.e. none)

Besides, what's with this "exactly" requirement anyhow? No two animals (or people, if you think we mustn't be counted as animals) behave exactly like each other either. Maybe we all come from different planets! There's a planet somewhere that's full of exact copies of me!

(And there's a world filled with nothing but shrimp. I grew tired of that world quickly.)

Or (like the other poster said), maybe we come from Pak. That's a hell of a lot more likely than that Adam and Eve came from Mars.

Where's the map?

[amightywind]

If the stripping were real it would be a great result. Instead of reading about it I'd like to see it. Can someone post a link?

Re:Aliens?

[ettlz]

Perhaps Adam and Eve were real and the first couple to come.

Nah. Eve was faking it.

A map!

[Zinged]

Don't know if this is THE map, but it is a map of Mars Crustal Magnetic Field Remnants: http://photojournal.jpl.nasa.gov/catalog/PIA02819

Re:A map!

[phlegmofdiscontent]

Here's a link to a better map on the MGS website.

http://mgs-mager.gsfc.nasa.gov/publications/pnas_1 02_42_connerney/

The one you linked was from the original data back in 1999.

Re:A map!

[Zinged]

Aaaa thank you... yeah I was thinking that could not be THE Cool new map. ^_^

Comment removed

[account_deleted]

Comment removed based on user account deletion

Re:Aliens?

[ettlz]

I'm from Mars.

Oh, come on. Everybody knows that the chances of anything coming from Mars are a million to one. So take your vast, envious, luminous eyes, your mind immeasurably superior to ours, your tripodal fighting machine and your goddam dirty red weed, get back in that cylinder, screw the lid on, and go home to the planet whence you came.

Otherwise I'll get David Essex to sort you out.

Re:You know the third one was made of paper mache?

[advocate_one]

your link does not work... it wants me to register...

Please assist with the upkeep of civilization...

[ScentCone]

by thinking before you type. It's not "fishers," it's "fissures." You know, from the same root word that gives us "fission" (as in splitting the atom).

And why go to all the trouble of typing that extra apostrophe in "volcano's" when it forces people to then ask, "The volcano's what?" You're saying that something belongs to a volcano? Or did you mean to just use the plural, and simply say "volcanos" (as in, more than one volcano)?

I don't normally bother with this, but since you're asking a useful question that I can only hope some geologists will answer, I'm just hoping you'll include some more helpful spelling/syntax/punctuation next time around. It elevates the conversation, and reminds the IM kiddies that words actually mean something.

Re:Aliens?

[coronaride]

pak homeworld? Is that anywhere near the "Zoq Fot Pik" homeworld? no wonder i like frungy so much...it's the sport of kings, you know...

Re:Aliens?

[lav-chan]

FYI, this is a (rather lame) meme that started on Fark a few weeks ago. Basically you post that whole thing, but replace 'I'm from Mars' with whatever is relevant to the subject (i think it started out as 'I work for US Mint').

Re:Aliens?

[stanmann]

Well, the tires on my hyundai are 99.9% similar to the tires on your Honda, they must have evolved. Or perhaps design was involved.

Best evidence for water

[Council]

To me, the best evidence for water is this map, which they always show at NASA presentations on Mars. It's a topographic map colored by altitude, and you see that the areas below a certain depth are almost completely crater-free, contrasted strongly with the areas above that depth. This, to me, is a really, really strong argument that it was once covered in water and had a coastline.

Looking at that map always makes an Earth-like Mars seem much more real to me.

Re:Best evidence for water

[digidave]

I was under the impression that Mars was once most likely covered in a shallow sea. This would explain the topography better than a deep ocean would. It could also explain the lack of crater impacts (dark color or not... there are less crater impacts where this sea supposedly is).

It's also possible that the low-lying portions of the planet are or were more susceptable to tectonic forces, so the topography has been smoothed by more recently replaced ground.

"just checking"

[digitaldc]

my error, I am only humanoid

ARES project

[Council]

When I interned at NASA/Langley Research center, I heard constantly about the ARES Project, which they're going to use to survey Mars's magnetic field in much greater detail than the global surveyor (among other things).

And it will be the first airplane flight over another planet's surface, just 100 years after the Wright brothers first did it here.

Re:ARES project

[Council]

Proper link here.

Re:ARES project

[digidave]

What's interesting, and perhaps addressed in your link, is that flying on Mars is completely different from flying on Earth. With low gravity it may seem easier, but at only 1% of Earth's atmosphere there is not enough air viscosity for a standard airplane to fly. It cannot generate lift nor maneuver once in the air.

X-Plane (http://www.x-plane.com/) provides a simulated Mars flight and includes a couple of airplanes that are designed to fly on Mars, but even those planes still do not provide enough control over the craft for it to be useful.

Re:ARES project

[kurtu5]

Damn those Reynolds numbers But, some guys over in my neck of the woods have agood solution.

Entomopter(a jpg not a pdf)

Video

Re:Please assist with the upkeep of civilization..

[joranbelar]

Or did you mean to just use the plural, and simply say "volcanos" (as in, more than one volcano)?

Or, more accurately, "volcanoes" :) </pedantic>

Re:Aliens?

[Ginnungagap42]

It's toward the galactic core. It was destroyed in the core explosion, 10000 years ago.

The original poster was referring to Larry Niven's Pak from the Known Space series of books, specifically "Protector."

Re:Please assist with the upkeep of civilization..

[ScentCone]

You say potatoes, I say potatos. At least you didn't say volcanoe's!

Re:Aliens?

[Locke2005]

Uh, every animal does not behave exactly like every other animal. We behave a lot more like Bonobo chimps then a cow behaves like a dog. Where do you want to draw the line -- mammals are from Mars, but reptiles are from Venus?

Re:Aliens?

[PakProtector]

Seeing as how we do not behave exactly like every other animal, would there be a way that we could have come from Mars? Perhaps Adam and Eve were real and the first couple to come.

Rubbish. We came from the Pak homeworld.

Yes, yes you all did.

Now, if you breeders would simply shut up and let us Adults do the thinking, things would get better.

Sincerely, Brennan-monster.

Re:Aliens?

[PakProtector]

We Pak evolved from mutated Food Yeast, too. Don't you recall the Slaver War?

Re:So what happened?

[PakProtector]

What offed the Martians? Global warming, nuclear war, terrorism..?

Ice Comet.

And it wasn't so much terrorism as it was genocide.

Sincerely, Brennan-monster.

PS: You're welcome.

Re:Is that really a word ?

[Zinged]

Ha! Crustal would seem it was made up, but according to Merriam-Webster's Online Dictionary it's real:

http://www.m-w.com/cgi-bin/dictionary?book=Diction ary&va=Crustal&x=19&y=17

Re:You know the third one was made of paper mache?

[Thud457]

Sorry about that. IMDB's getting to be kind of an ass about that the last year. I use the bugmenot plugin for Firefox. Freanin' awsome.

Re:Aliens?

[PakProtector]

It's toward the galactic core. It was destroyed in the core explosion, 10000 years ago.

The original poster was referring to Larry Niven's Pak from the Known Space series of books, specifically "Protector."

What do you mean, 'Series of Books?'

Sincerely, Brennan-monster.

Re:Aliens?

[ediron2]

A better (and open) question is whether all life on Earth is descended from (primitive) life that originated on Mars and was carried here by meteorites before Mars became uninhabitable.

A better question? An open question? Really!?

Not meaning to troll, but how exactly would a meteor jump or ricochet off mars and impact Earth? The idea just seems damned far-fetched. And wouldn't the atmospheric burn leaving mars and impacting earth and months or years of hard vacuum time do a nice job of sterilizing most things? And if this idea you posit says earth's organisms needed to come from Mars, where'd Mars get 'em?! After all, any creation story that posits that it is 'monkeys all the way down' loses my confidence pretty damn fast.

Given the huge range of temperatures, minerals, electrostatic activity, etc. here on earth, seems easier to imagine various 'crawled out of primordial soup' origin theories to space debris carrying lucky spores or enzymes. I mean, I like my infinite-improbabilities when they come packaged in a world that rolls the dice a millions of times per second for a few billion years.

Again, I don't mean to troll. We can't prove or disprove what you're suggesting, but your suggestion starts with 3 or 4 soon-to-be-tested requirements (residue of life-supporting ecology on mars, evidence of life on mars, that life's genetic resemblance to earth life, matching timelines). I even like seeing scientific trial-ballons like yours. But your idea seems astronomically unlikely given the alternatives.

Version 1

[LaughingCoder]

Hmmm, maybe Mars was Earth version 1. Then the designer addressed the defects and came out with version 2.

Re:Version 1

[vertinox]

Hmmm, maybe Mars was Earth version 1. Then the designer addressed the defects and came out with version 2.

Actually, Mars was the backup planet, but after the designer position got outsourced to a job in the Eastern nebula they decided to not bother with doing nightly backups anymore.

Re:Aliens?

[Ginnungagap42]

Not "series" like a "trilogy", but rather several novels written against the same milieu. Niven's "Protector" is wholly devoted to the Pak, but they are also featured in:
"The Ringworld Engineers"
"The Ringworld Throne"
"Ringworld's Children"

As I'm sure you know, based on your handle. :^)

Re:Aliens?

[ShibaInu]

It is not all that uncommon to find metorites on Earth which originated on Mars. ALH84001 is a famous example - it was the rock that NASA claimed might have had evidence of microscopic life. The question if life could survive the journey is not known.

solar system life started on Mars?

[peter303]

Mars cooled off sooner after formation than the Earth and probably became suitable for life tens of millions of years sooner.

Three dozen Martian meteorites have been found so far on the Earth. Probably thousands of more fell into the oceans or haven't been found yet. Drillholes in the earth find bacteria at least ten kilometers deep, so they can live in rocks long enough for an interplanetary journey. So its possible life arose first on Mars and then infected the Earth.

Re:Aliens?

[PakProtector]

Not "series" like a "trilogy", but rather several novels written against the same milieu. Niven's "Protector" is wholly devoted to the Pak, but they are also featured in:
"The Ringworld Engineers"
"The Ringworld Throne"
"Ringworld's Children"

As I'm sure you know, based on your handle. :^)

Oh, you mean the Historical Documents?

First Life on Mars

[MightyMartian]

I think the big justification for saying life might have first developed on Mars is that Mars was likelier a better place for chemical abiogenesis earlier than Earth. However, one of the more recent SciAm's had an article on how Earth may have had liquid oceans several hundred million years earlier than earlier thought, so I'm not too sure how well this idea is really flying now. I never really thought much of it to begin with.

Re:Aliens?

[Ginnungagap42]

Yup. :^)

Re:Aliens?

[ediron2]

Crap... elephants all the way down, not monkeys. Various claimed origins to the phrase, but I first heard it was a 19th-century exchange between a western theologian and a hindu/sikh/? priest describing their cosmos as one that has the earth riding atop a giant sea turtle standing atop an elephant that is on an elephant that is on an elephant etc. Says the priest: "You don't seem to understand, Doctor: it's elephants all the way down."

Had the probability stuff I mentioned (and the infinite number of monkeys) on the brain and that garbled things, I guess.

Don't blame me

[oliverthered]

Don't blame me, blame the English language. Compaired to my writing errors my coding errors are non-existant, so I don't have any problems writing logically and accurately the English languages has problems letting me.

Maybe I should start learning Mandarin.

Re:Aliens?

[Carthag]

Oh wait, you're right. Sorry about that, I'm just a breeder.

Re:Aliens?

[Shotgun]

It is very uncommon, and the idea that they're from Mars is a VERY tenous idea at best. According to http://en.wikipedia.org/wiki/Martian_meteorite the idea is basically, "It doesn't look like it is from here, IT MUST BE FROM MARS."

Not exactly what I'd call science. I'd tend more to calling it "making shit up".

No,no,no, they found some other evidence

[jurt1235]

Copyright and patent laws engraved in the martian rock.

Re:Aliens?

[vertinox]

Well, the tires on my hyundai are 99.9% similar to the tires on your Honda, they must have evolved. Or perhaps design was involved.

Apparently, god must be the Firestone tire company.

But seriously, if intelligent design was involved we would be able to see radiation, breath underwater, survive more toxins, or be able to naturally fly. I can think of at least 100 different items the human body could improve itself on.

We are a very limited organism.

Not to mention all the defects we get naturally... Blindness, old age, cancer, mental handicaps, heart disease, obesity and don't forget birth defects...

Re:Don't blame me

[oliverthered]

Are you inserting typos intenionally in order to maka a point?

Maybe, my browser highlights spelling errors so you'd think I'd bother to correct them, unless I like spelling nazis.

Evolution, schmevolution

[Kelson]

Actually, evolution isn't necessary -- individual adaptation will be enough to prevent Mars-born humans from easily returning to Earth. Considering how much bone and muscle mass people lose on extended stays in free-fall, I imagine people growing up in 1/3 Earth gravity are going to develop differently than people growing up in full Earth gravity.

It's hard enough to move from a warm climate to a cold one -- and that's something you can usually adapt to within a year or two. Now imagine moving to a planet with 3 times the gravity your bone structure is built for.

(Of course, when you add the effects of evolution on top of that, there's probably potential for actual speciation...)

Re:Aliens?

[CagedBear]

Uh, every animal does not behave exactly like every other animal. We behave a lot more like Bonobo chimps then a cow behaves like a dog. Where do you want to draw the line -- mammals are from Mars, but reptiles are from Venus?

Well, if I had to draw a line it would be between those species who question their origin and those who don't.

Re:You know the third one was made of paper mache?

[advocate_one]

next to useless... nice idea, but they appear to block accounts very fast... I tried 15 different bugmenot accounts and made sure everyone that failed was reported to bugmenot as dud. The sixteenth worked, but cos they'd used a fake email address, they'd never finalised the validation process.

SO guys, if you're gonna create a bugmenot account for imdb, fer hecks sake use an email account with one of those throwaway jobs so the process can be finished.

Re:Aliens?

[master_p]

Not only we are similar to other animals, but our habits are totally similar to other animals too. We eat twice a day, we sleep, we have sex (yes, even /.ers), we protect our women and children, we use body language to transmit our real feelings, and our everyday experience is still defined by the basic animal instinct: to flee when there is danger, to attack when there is benefit.

Re:Aliens?

[Ralph Spoilsport]

first, we do behave like every other animal - we are born, we eat, we grow, we fuck, we reproduce, we die. Everything else is just window dressing.

secondly, If you believe in fairytales like Adam and Eve, then, OBVIOUSLY, they were the first couple to COME, because they were the first couple to FUCK. And COMING is one of the best parts of FUCKING.

Stupid Xian Trolls don't even know when they're being funny.

RS

Re:Aliens?

[m50d]

Not meaning to troll, but how exactly would a meteor jump or ricochet off mars and impact Earth? The idea just seems damned far-fetched.

It happens all the time, a lot of meteorites we have come from Mars. I don't know how it happens - possibly they're thrown out from other impacts - and it surprised me, but it's true.

And wouldn't the atmospheric burn leaving mars and impacting earth and months or years of hard vacuum time do a nice job of sterilizing most things?

Bacteria are pretty darn tough. We've found them alive on things that have been left on the moon (IIRC) for two years. They could live deep inside the rock, and spread out to the puddle the rock has landed in once it's come to rest.

And if this idea you posit says earth's organisms needed to come from Mars, where'd Mars get 'em?! After all, any creation story that posits that it is 'monkeys all the way down' loses my confidence pretty damn fast.

Assuming our current theories on the history of both planets are correct, Mars had a lot more time for life to arise. My figures may be off a bit but we think that just 20 million years before life arose on Earth the planet was being heated past the evaporation temperature of rock on a pretty frequent basis. Wheras Mars had been reasonably temperate for a billion and a half or so of our years before that.

Given the huge range of temperatures, minerals, electrostatic activity, etc. here on earth, seems easier to imagine various 'crawled out of primordial soup' origin theories to space debris carrying lucky spores or enzymes. I mean, I like my infinite-improbabilities when they come packaged in a world that rolls the dice a millions of times per second for a few billion years.

If you're saying life can arise as quickly as it must have done to come up here on Earth then the Femri (sp?) paradox becomes pretty serious. I mean, it's believable, and there are possible environments on Earth that were more stable and life-friendly even while the surface was still being bombarded (e.g. black smokers at the bottom of the oceans, when said oceans weren't boiling off), but most are missing some critical component for life, and getting them out to the rest of the planet is often just as hard as getting something from Mars.

With Mars, you have several orders of magnitude more time, and far more space than in any of the stable-ish terran environments. And once a planet has life, you get it everywhere - there isn't one place on Earth (at least within a few kilometers of the surface) that doesn't have at least bacteria, even inside rocks. so then all you need is some of the Martian bacteria to survive a few months in space - not easy, but something we know our bacteria can do - and re-entry - harder, but quite possible - and then land somewhere they can survive, a piece of cake next to the other two bits.

Again, I don't mean to troll. We can't prove or disprove what you're suggesting, but your suggestion starts with 3 or 4 soon-to-be-tested requirements (residue of life-supporting ecology on mars, evidence of life on mars, that life's genetic resemblance to earth life, matching timelines). I even like seeing scientific trial-ballons like yours. But your idea seems astronomically unlikely given the alternatives.

It's not my idea, it's a serious hypothesis that explains things about as well as the alternatives. It's very difficult to guess how life started just because it's so long ago, but this is as good a theory as any given current evidence. As you indicated, it will soon get some pretty strong support or damning evidence against once we can see whether mars supported life.

Re:Aliens?

[luna69]

Yes, well, we all know that Wikipedia is the final arbiter of truth, now don't we?

Isotope comparison is well understood. It's not "making shit up". And it certainly is "science".

Perhaps you're using some sort of weird alternate definition of the word?

I wonder...

[Short Circuit]

...if locally-generated magnetic fields would be useful as a radiation shield.

You'd need a shell or netting of high permeability to keep the magnetic field from screwing up local electronics, though.

Google

[manojar]

Has Google come up with Google Mars yet?

Re:Google

[butterwise]

nope.

Re:Aliens?

[EtherealStrife]

Actually, that's exactly what happened. The tires are adaptations of predecessors: hyundais are crap cars (I recall a time when one of the original boxy ones caught fire while I was in it...owner was prepared with a fire extinguisher though...you gotta be, driving korean cars :) ) and are designed for maximum cheapness. In this example, the tires that honda modeled theirs on were viewed by the Hyundai car company as efficient/cost. But just to add that extra cheapness, they tossed the neighborhood cat into the vat instead of the last .1% of rubber. Honda did not see the need for the neighborhood cat, since their cars are merely "Economy". Both are descendants of the same original tires, but have slight alterations that set them apart.

DISCLAIMER: I have nothing against koreans, I just REALLY hate Hyundai. And I realize Honda and Hyundai don't make tires (hyundai makes just about everything else, oddly enough), it just fits nicely.

Re:Aliens?

[ediron2]

1 rock. Might have had evidence of life. No mention of *how* stuff jumps off mars and hits earth, which was pretty much my request.

Again, compared to the 100 lightning strikes per second earth gets.

Occam's razor, anyone?

Re:Aliens?

[ediron2]

Thanks for the detailed posting. By the last paragraph, I found myself splitting between agreeing that it is a serious hypothesis, but disagreeing that it explains things as well as the alternatives. This'll sound disrespectful, but the monty-python quote that comes bubbling up is "Watery tarts throwing swords..."

150 million square km of earth as a petri dish, things like volcanic/tidal activity and 100 lightning strikes per second causing all sorts of wierd compounds to be created in varying quantities. Thermal spectrums from damn-cold to boiling. This genesis scenario just seems more likely than the rare chance of innoculation by space-rocks.

I accept the mars-rock is possible. Just damned unlikely compared to the alternatives.

Laaalalalalalalaalalaa Kata-Mars-i Da-Marshiiii...

[blagh]

Is it just me (or the lack of sleep), or does Mars look like a giant Katamari with its magnetic fields drawn in like that?

Seas or lava or dust?

[Tipa]

Mightn't the less-craterful areas just be areas of more recent lava flow, or just places where dust had settled.

Re:Aliens?

[Shotgun]

No one is disagreeing on the applicability of isotope comparison, but obviously you didn't bother to read the Wikipedia article, so I'll quote for you:

Mars meteorites include three rare groups of achondritic (stony) meteorites (16 objects total) with isotope ratios that are said to be consistent with each other and inconsistent with the Earth. It should be pointed out, however, that the isotope ratios do not actually match Mars ratios especially well, to the extent that Mars ratios are known, although they do differ substantially from Earth isotope ratios and from what is known of Lunar ratios.

"It doesn't match what we know of Earth rocks, so IT MUST BE FROM MARS!!" vs...an asteroid... Mercury...Io...???...no one REALLY knows; therefore, ipso facto, and following good grammar rules, they made the shit up.

Perhaps you get your idea of what 'science' is from the cable tv network.

Re:Aliens?

[luna69]

Actually, I did read the wikipedia article. What I am doing is pointing out that wikipedia is not an authority on this, or many other, matters. The Xenon, Argon and Krypton ratios used for dating aren't a mismatch as noted above - this is one wikipedia editor's opinion. The fact that something is on wikipedia doesn't mean much.

The author/editor's opinion is presumably based on the Swindle/Brier/Burkland article in Geochimica et Cosmochimica acta in 1995. I don't believe this is a warranted reading of the evidence, and the scientific community doesn't either.

Moreover, I'm an astronomer. With a degree. So my idea of what science is - and more importantly, how it's done - has little little or nothing to do with cable tv.

Re:confusion...

[bhiestand]

But also the surface of mars has much evidence of erosion and it has cannons and such so i can see how it has tectonic plates as well!

Your teacher told you about the cannons on mars? Shame on him! That wasn't supposed to be declassified until the year 2150. Of course you'll probably be almost 162 years old by then, but with the help of modern tectonic heating plates, mars cannons, and incompetent Science teachers, you should be able to live that long. Unless, of course, you go to mars. Then your odds are much, much lower.