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What Happened To the Martian Ocean and Magnetic Field? (theatlantic.com)
schwit1 writes with this story at The Atlantic that explores what may have destroyed the Martian atmosphere and ocean. The question of whether there is life on Mars is woven into a much larger thatch of mysteries. Among them: What happened to the ancient ocean that once covered a quarter of the planet's surface? And, relatedly, what made Mars's magnetosphere fade away? Why did a planet that may have looked something like Earth turn into a dry red husk? “We see magnetized rocks on the Mars surface,” said Bruce Banerdt, the principal investigator of the InSight mission to Mars, which is set to launch in March. “And so we know Mars had a magnetic field at one time, but it doesn't today. We would like to know the history—when that magnetic field started, when it may have shut down.”
... that because of Mars' small size, it cooled faster, thus freezing its outer core and shutting down its dynamo? Isn't Venus the far greater mystery? Nearly the same size as Earth, yet no magnetic field and what appears to be occasional whole-crust overturn rather than plate tectonics? Isn't that the one we need to solve?
The human body can be drained of blood in 8.6 seconds given adequate vacuuming systems.
Mars has no Magnetic field because it's core cooled and is no longer a active moving iron mass. it cooled faster as it has very little radioactive isotopes and being further away from the sun it has less energy pounding it to slow the cooling.
http://www.scientificamerican....
Plus we had an event late after the formation of the planets in the solar system that also added a buttload of energy, when the moon was formed from a planetary sized impact.
Do not look at laser with remaining good eye.
Lack of a magnetic field is one of the biggest obstacles to proper terraforming. If there's really a turning point within reach, that we one day might trigger artificially, then Mars becomes a lot more attractive. If we could restart its magnetic field, it could have a stable Earthlike climate someday.
Triggering crystallisation of a planet's core is left as an exercise for the reader, and would be incredibly difficult, but it's a lot more plausible than trying to supply enough heat to start convection by any other means.
While trying to figure out what scripts to allow to make moderation work I accidentally ended up modding this as flamebait. For reference, I was going for informative. I believe posting a reply will undo that. So thanks for the post, Lumpy. I owe you +1.
Strip off? But where did those 1-2mm go?
It was Marvin the Martin, in the Valles Marineris, with an Illudium Pu-36 explosive space modulator.
systemd is Roko's Basilisk.
We all turn into solar radiation zombies.
You have about 1.2 Billion years to prepare for this, so start digging and stocking your bunker now.
Do not look at laser with remaining good eye.
Is the loss of the magnetic field related to the disappearance of the Martian ocean? Another commenter seemed to indicate this, but I don't get the connection and it's been 30 years since I've taken chemistry or physics.
You are welcome on my lawn.
I know you jest, but I was just reading something about the prevailing Christian belief regarding extraterrestrial life is that it's possible, but they would have no souls. Like gingers.
You are welcome on my lawn.
So what would it take to re-heat the core to restart magnetic field? What kind of energy input would it take, and what could deliver it? Could we just crash a bunch of large asteroids into mars then wait for the surface to cool?
So let's crash the moon into Mars and see if it restarts the core.
-- Make America hate again!
Also there is a theory that Mars got hit by something big on the opposite side of the planet from where Olympus Mons is and that it may have disrupted things enough to cause it's dynamo to stop earlier than it should have and for the core to lose it's heat much faster from the Olympus Mons eruptions due to the collision.
"I don't which is worse, that everyone has a price, or that the price is always so low"--Hobbes
20+ posts already, and no one mentioned Global Warming yet? How could you, guys, miss this opportunity to refresh the fear in the hearts of your followers? If you keep burning fossil fuels, our planet too will become an airless desert devoid of life. Whether it will heat up or cool down is an impolite question, but something will happen, unless you install solar panels on your roof.
The "point of now return" — like the second coming of a deity of some unscientific cult followed by the unwashed — has been within "only a few years" for the past 4 decades.
Gebyy zl gnvy.
In Soviet Washington the swamp drains you.
Then we get another movie.
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
Breathing is carbon neutral. Your joke would have been funny if you stopped one line earlier and didn't go full retard.
Unicode killed the ASCII-art *
Only if "proper" means that one is fixated on creating an Earth-like habitat that is planet-wide and open to the stars. That's traditional, but it's not sensible engineering because it's not resource-efficient.
Instead, it makes a lot more sense to create your own habitable layer no larger than is needed, to do so in segments so that not all your eggs are in one basket, and to extend it only when more space is needed. There are numerous different variations on this theme, all of them much more sensible than wanting to terraform a whole planet with an open atmosphere.
Whether it be domed cities or a tunneled crust or anything else, it wouldn't be all that different to Earth in practice because even here we are limited to a narrow planetary niche. We can't survive without protection much higher, much deeper, or even at the same level in many places on Earth, especially in the vast oceans which cover most of our planet, so it's a misconception to think that it's fully habitable by humans.
And that's something we can create on Mars, a partly habitable environment. Don't get hung up on wanting planet-wide open terraforming, it's a quaint idea but it's not at all sensible.
It is thought to be related to the disappearance of the Martian atmosphere. The magnetic poles divert the solar wind towards themselves, and prevents it from hitting most of the planet. When the magnetism disappears, the solar wind blows the atmosphere away.
When the atmosphere disappears, the pressure is reduced, and with it the boiling point of water, until water can only have two states - ice and gas form. The water that doesn't turn into ice goes the same way as the rest of the atmosphere.
Magnetic fields definitely help slow atmospheric loss, but I think a lot of scientists are overestimating the effect on Mars. Either Mars never had much of an atmosphere, there is some extreme tipping point between atmospheric pressure and gravity, or the atmosphere is still mostly there, just sunk into the surface of the planet. Otherwise there is no way that the atmosphere of Venus, which also has no real magnetic field, could be nearly as thick as it is today.
Aren't we due to stick our heads out from the protective Galactic Disk and magnetosphere to get fried by intergalactic cosmic rays long before then?
Apocalypse Cancelled, Sorry, No Ticket Refunds
Not really carbon-neutral. A lot of our food is not only indirectly dependent on fossil fuels, but contains direct oil/gas derivatives. And I didn't even started talking about cheap hard drinks. Or soda.
Into space.
"What the American public doesn't know is what makes them the American public." -Ray Zalinsky (Tommy Boy)
Millions of years ago Earth, Mars and Venus formed an artificial Klemperer rosette in the habitable zone around the Sun.
The advanced civilisations which produced this artifact went to war. Mars and Venus' orbits were wrecked. Mars was hit by 'planetbuster' bombs and cracked open, its molten core spewing out into space and collapsing on itself. Venus was subjected to bombardment by comets and turned into the hell-hole it is today. Only Earth survived mostly intact.
Either that or the civilisation which produced the rosette went into decline and could no longer maintain the technology that kept this unstable formation from breaking up into what we see today.
In the free world the media isn't government run; the government is media run.
Even as far back as the original Cosmos series, scientists were saying that the lack of a liquid iron core to generate the magnetic field was the cause of the atmosphere leaking off into space. Okay, sounds plausible but it has me wondering why it has to be liquid when lodestone has a magnetic field and it's solid.
And why isn't gravity enough to hold the atmosphere in? Or is the gravitational field too weak?
Very sublime observation
We have a long time to figure out how to get along well enough to emigrate to another world.
And if we haven't figured it out by then, we probably don't deserve to have another shot at a world.
Sig for hire.
It's this exactly. Without a magnetic field, the solar wind dried out the planet and blew away a large amount of the already thin atmosphere. The low gravity didn't help any. The planet had a lot going against it from the beginning and was probably never a good place for complex life to appear. Barring some sort of cosmic change like how we got our moon and added a huge amount of iron and mass, Mars was always doomed to end up freeze-dried.
We currently have no way of fixing this problem so all the grand plans to terraform Mars won't work, unless they also restart the magnetic field, which we don't know how to do. It might take slamming a proto-planet into Mars to get things going again, which we can't currently do, and which would also make the planet essentially unusable for hundreds of millions of years, at least.
It also risks all kinds of other issues like disturbing other planets and introducing a lot of chaos into the solar system. But luckily we don't know how to knock planets into each other. And I suppose if we DID and we had that sort of tech, we would not need to bother with Mars. We'd just find a suitable planet elsewhere, which is probably easier.
Sig for hire.
The way I understand it the lost of the magnetosphere allows the solar wind to push the ozone back to the nightside and some off into space, this thins ozone lets the UV disassociate more water vapor (that's lighter than air) into hydrogen and oxygen, the hydrogen is lost to space because it's so light and the oxygen that doesn't get blown off into space oxidises any methane or carbon monoxide in the atmosphere on the way back down to the surface. This causes the atmospheric pressure to decrease, which cause the water to boil at a lower temperature, putting more water vapor into the air to be dissociated and lost, in an accelerating death spiral.
Apocalypse Cancelled, Sorry, No Ticket Refunds
First manned flight to Mars may very well be landing on one of the Martian moon, Phobos, first. A later manned flight will land on Mars itself.
http://www.space.com/29349-manned-mars-missions-phobos-moon.html
Yes, and the event that formed the moon probably gave us a larger molten iron core. I have seen a hypothesis that the gravitational forces from the moon also help keep the iron dynamo moving in the core. I don't know how likely that is, not being a physicist, but it is an interesting idea.
Is the backwards spin evidence that cats had used the Venerian spin to get their planet moving.
Actually, any oceans were lost because Mars is not massive enough to keep them.
Thank you.
You are welcome on my lawn.
We currently have no way of fixing this problem so all the grand plans to terraform Mars won't work, unless they also restart the magnetic field
The process of bleeding away the atmosphere happens over geological time spans. If we could increase the density of the atmosphere it would still be there for tens of thousands of generations. I would not call that a terraforming failure. Given that you're argument is based on that one misunderstanding, your pessimism seems to have political roots, not intellectual roots.
The age of the Earth (and presumably Vanus) is about 4.5 billion years. 100 million years is about 2.2% of that. An event that takes 100 million years could happen 45 times in the Earth's lifetime. If it were a day, this would be about a half hour lunch. So more of a moderate length of time, geologically.
Compare it to what the Earth looked like 100 million years ago.
Sure it does. Depends on how fast you spin it and for how long.
Yes it has more gravity, but not that much more. Using Earth as a reference (1G), Venus is 0.9 g and Mars is 0.376 g. That can definitely account for some additional atmosphere but not that much (92 times Earth sea level pressure), especially when considering that more atmosphere means a higher atmosphere which is more susceptible to being stripped off. You have to go 50 KM high before atmospheric pressure even drops to Earth sea level pressure. SOMETHING is happening besides the solar wind.
"... it would still be there for tens of thousands of generations." Not good enough. If you make Mars habitable, that work will get leveraged, as in it will be inhabited. What will those distant generations think if we set up an unstable atmospheric dynamic and knowingly doom future generations to suffocating? The atmospheric dynamic must be stable, like it is on Earth. Robust and even largely self-correcting.
Not really. If we can do it once, we can keep it supplied with atmosphere in plenty of time. We keep importing resources to places that don't have them all the time. However, although about a fifth of the needed material might be already on Mars in the form of ice, the only real option would be to bring in comet type material from the oort cloud. Last time I did rough estimates on doing that, the energy needed to move all that material in ten years was measured in days total output of the sun. Move the cometary material slower, and it takes longer but the energy needed is less. Increase the time to 10,000 years, the time that an astrophysicist friend of mine said it would take for Mars, give an Earth-like atmosphere to degenerate to one that wasn't, and that makes the constant power requirement to keep Mars supplied with atmosphere at 3.8*10^14 W. That's about 2000 times what the we generate currently on the Earth, just to keep Mars' atmosphere stable.
It's also been proposed to ship Venus' atmophere to Mars, but I haven't seen any estimates on the energy needed to do that.
Did you see the machine in Total Recall? It warmed the water, but also generated a magnetosphere. They shut it down before leaving as running without maintenance it would just break down. That does mean that once we turn it back on we need to figure out how fix it, but at least we will have blue skies and protection from the Sun while we study how the machine works.
*This is a joke, not a troll, or a belief of intelligent life forms on mars*
Microsoft, Apple, Google, Amazon what's the difference? All steal money from devs and control with walled gardens.
Thats 500 to 1000 kilometers a billion years. I am not sure how small the outer liquid core must get before the dynamo halts. Someones probably modeled that.
Any link to that theory? I was pretty sure the accepted theory on Olympus Mons is it built up over time due to the fact that plate tectonics stopped and it was stuck over a magma hot spot.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
I thought the idea was that either they had their own incarnations of the resurrection/redemption story, or that they were not as wicked thus would not have killed the Christ so Earth was chosen and the redemption was universal.
I kinda like the 2nd one. We were chosen because we were special.... just not in a good way.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
The heavy isotopes sink down to the core of planets. If hot then the densest metals transfer heat to the lighter elements. I've given this some thought. If the horse head nebula is second generation stars then there isn't enough plutonium and uranium present to maintain heat for billions of years. The Sol system is at least a fifth generation star having components from early star collisions and nova events. The gold on earth is from neutron star collisions billions of years before this system existed. Any planets in the horse head nebula are facing the exact same problem as Mars. Too few heavy metals.
Too many and you wind up with Mercury. Plutonium core surrounded by lead. Venus had enough heat internally to resurface itself, erasing nearly all meteorite craters. Venus's proximity to the sun doomed it to a run away greenhouse effect.
The Earth has the right mix of distance from the sun... heavy metal mixtures... lunar mass(asteroid buffer)... Amino acid levels... and we shouldn't discount theories that the outer star system was in a liquid state four billion years ago. Life may have started near Jupiter and made its way inwards as the young star cooled down.
Once life started out there it changed each habitat to suit itself. A lack of sunlight in the outer system means methane breathing bacterium. Same as Earth's diverse genomes. RNA or DNA doesn't really matter. There is also circular MtDNA. If we explore the galaxy we will probably find right handed DNA and RNA.
You're weird, I breathe air, you seem to breathe food.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
“We see magnetized rocks on the Mars surface,” ... “And so we know Mars had a magnetic field at one time"
I think all we can say with reasonable certainty is that rocks on the Mars surface were exposed to a magnetic field. As far as I've found, there's no observable evidence that the magnetic field must have come from Mars itself, or even that the rocks were impregnated with magnetic alignment while they were on Mars.
Europa for example has a magnetic field that was induced by Jupiter's own field and was not created by Europa itself.
https://ned.ipac.caltech.edu/l...
It's understandable science has to do it's due dillegence but seriously, i wish they'd just take Sitchin a little more seriously.
$action = empty(PHP) ? backToC() : unset(PHP) ; "when the concrete cases are understood, the abstractions are readily
The O2 has to combine with something to make the CO2...
The energy taken to terraform mars would be better used on Venus or towards pressurised structures. And those will be very simple as you need only about 7-8 psi capability
Do not look at laser with remaining good eye.
1.2b years and start digging now? Why? Tectonics will destroy whatever hole I make by then.
Mars does have magnetic fields, I don't know why anyone is saying differently.
Earth has a global, powerful magnetic field. Mars does not.
Considering Mars is approximately the same age as Earth but with around one tenth the mass, I don't see why that's a huge mystery. You would expect a smaller, lower mass orb to cool more quickly, even if just because the ratio of volume to surface is so much greater.
Having said that I'm not a areologist or even a geologist, so I'm quite prepared to be wrong and maybe there's something more subtle going on.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
How about about one rotation every 25 hours (give or take) for 4.5 billion years?
-- 'The' Lord and Master Bitman On High, Master Of All