Research Suggests Mars Once Had a Thick Atmosphere

astroengine writes "At one time, Mars had a thick, protective atmosphere — possibly even cushier than Earth's — but the bubble of gases mostly dissipated about 4 billion years ago and has never been replenished, new research shows. The findings come from NASA's Mars rover Curiosity, which has been moonlighting as an atmospheric probe as it scours planet's surface for habitats that could have supported ancient microbial life. 'On Earth, our magnetic field protects us, it shields us from the solar wind particles. Without Earth's magnetic field, we would have no atmosphere and there would be no life on this planet. Everything would be wiped out — especially when you go back 4 billion years. The solar wind was at least 100 times stronger then than it is today. It was a young sun with a very intense radiation,' Chris Webster, manager of the Planetary Sciences Instruments Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., told Discovery News. Unfortunately for Mars, the last 4 billion years have not been kind."

Comments

Planetary magnetic field

[Anonymous Coward]

Without Earth's magnetic field, we would have no atmosphere and there would be no life on this planet.

Are we sure of that? While I can accept that Mars lost its atmosphere due to the solar wind stripping it, it should also be noted that Venus has a very weak magnetic field, yet it has a far larger atmosphere than the Earth. In fact, most of the magnetic field of Venus comes from the solar wind interacting with the atmosphere.

Re:Planetary magnetic field

[viperidaenz]

Which is why Venus has an atmosphere consisting mostly of CO2, the lighter hydrogen and oxygen gases get stripped off by the solar wind.
Hence no water on Venus or in its atmosphere

Re:Planetary magnetic field

[Anonymous Coward]

This is an unconvincing argument. Hydrogen would escape into space without the solar wind. And free oxygen is not a normal thing. It required life for it to be released on the Earth (from CO2). And as far as the high concentrations of CO2, the Earth has methods to store it as limestone which makes Venus look more extreme than the Earth even though the actual total carbon levels are similar. Thus, the inference that Earth couldn't have life without geomagnetism is still not conclusive in my opinion.

Re:Planetary magnetic field

[IndustrialComplex]

You are correct that the solar wind would strip off hydrogen, but the reason it isn't stripping it isn't due to the magnetosphere alone.

Part of the reason Earth has hydrogen is because it also has oxygen. While the two elements (at least hydrogen) would be stripped by the solar wind if they remained separate, the Hydrogen is 'weighted down' by being bound in water molecules with Oxygen.

The solar wind has stripped most of the Helium from our planet's atmosphere because it is a noble gas and doesn't react with other elements. If the solar wind is already strong enough to strip off the He, it would certainly be strong enough to strip off the much lighter Hydrogen.

Once again I'll say it

[TheGoodNamesWereGone]

We need to put boots on Mars

Re:Once again I'll say it

[ruiner13]

Wow, it used to have a thick atmosphere AND feet? Awesome! What is Mars' shoe size?

Re:Once again I'll say it

[EzInKy]

Am I the only one who is bored beyond tears with these Mars revelations?

My guess is that the vast majority of non-nerds are just as bored with extraplantery discoveries as you. The majority here though are probably keen to get as many of these science stories as they can.

Re:Once again I'll say it

[Sperbels]

To protect its feet. Duh.

Terraforming Mars

[Firethorn]

If we're going to terraform mars, I say we should go big.

Collide Mars and Venus together, that gets you a planet that's 92% of the mass of the Earth. Maybe add Mercury in there as well, that gets you 98%.

Move to an appropriate orbit and wait for it to cool... ;)

With the violence of the impact, you should be able to get a magnetic field going. I figure that the collision that created the earth & moon is what kickstarted ours.

Re:Terraforming Mars

[kcmastrpc]

The molten iron core gives earth a strong magnetic core. How do you figure a collision created this?

Re:Terraforming Mars

[datavirtue]

Immanuel Velikovsky, is that you?

Re:Terraforming Mars

[Firethorn]

Think of a planet like a giant centrifuge. Smash the two planets together and you'll create enough heat that you'd end up with a massive molten mass. Have the hit be 'off center' and you'll impart a huge amount of kinetic motion. Between gravity and centrifugal forces the heavier elements like iron will tend to end up towards the center while spinning, thus creating your magnetic field.

Re:Terraforming Mars

[FatLittleMonkey]

Move Venus to MSL3 and spin it. As the atmosphere cools, drop chunks of Ganymede every few years for water and possibly organics. If it cools too far (unlikely with all that CO2 and added water), move it to ESL3.

Colliding Mars and Mercury into Venus adds nothing of value, certainly nothing worth the hundred million extra years you'd need to wait afterwards.

Re:Terraforming Mars

[Anonymous Coward]

Assuming an Earth-sized planet in Venus orbit, even at its very closest, it would only accelerate the Earth at about 3 mm / s^2. If we can manage to move Mars and Mercury to collide with Venus in such a way that all material is maintained by Venus, such a minute effect on our orbit is meaningless. But since we're dreaming up unicorns, let's move Mars to be a moon of Venus instead. Then we can terraform both and have a nicely habitable double planet.

assumptions

[Anonymous Coward]

Basically they start with the assumption that mars once had had free-flowing water.
That implies that the atmosphere should have had higher partial pressure than exists today (otherwize there wouldn't be any free flowing water).
This was not their research.

Given that assumption. These researchers looked at the profile of isotopes in the air and the ground and noted that the atmosphere isotopes skewed heavier than the models of dissolved gasses in the ground from other parts of the solar system. Then they hypothesized that if there was a thicker atmosphere at one time and was dissipated, the lighter isotopes would escape from the top of the atmosphere, leaving the heavier isotopes ratio in the thinned atmosphere. And they observed that this was true so it was consistent with this assumption.

Of course the original assumption about water may or may not be true. Or the composition of the dissolved gasses in the ground may or may not be true. Or the mechanism of lighter isotopes escaping from the top of the atmosphere may or may not be true. At best this is indirect circumstantial supporting evidence of a thick atmosphere hypothesis. Sadly NASA researchers trump up these things for the press to get ahold of (e.g., the ever reoccurring life-on-mars press announcements over the years).

How did it form an atmosphere?

[spectral7]

How did Mars form an atmosphere in the first place if it has no magnetic field to keep it from getting stripped away?

Re:How did it form an atmosphere?

[catchblue22]

How did Mars form an atmosphere in the first place if it has no magnetic field to keep it from getting stripped away?

One of my favorite moments in my formal education came when I took a second year geology elective called "Geologic Time". We spent some time discussing the formation of the solar system. If I may, I'll give a brief summary, as it will give some context to your question.

Many billions of years ago, a large star composed of hydrogen formed. Due to the high pressure and temperature in that star, new elements formed by fusion, with the largest element formed being iron. The star had a relatively short life, collapsed, and exploded in a supernova. During the explosion, neutrons, amongst other things were sprayed around the already existing matter. Those neutrons, being neutral, tended to "stick" to other nuclei. This, combined with beta decay explains the formation of elements larger than iron.

A wisp of the dust from that supernova began to coalesce into a spinning disk, due to gravity and angular momentum. The larger amount of material in the center of the disk was pulled together by gravity strongly enough to create fusion. Thus our sun was born. Within the spinning disk, some material was naturally volatile (e.g. water, methane, etc.). Some of the material tended towards becoming solid. One such material was silicon. The silicon reacted with oxygen to form silicon dioxide (I think). The silicon dioxide tended to form solid spheres in much the same way that hail is formed within a thunderstorm. These little spheres of silicon were commonly the size of ball bearings or actual hailstones. We call them chondrules.

When the sun ignited, it created an outwards stream of particles, which we call the solar wind. The particles in the solar wind easily pushed volatile molecules like water and methane outwards, away from the Sun. However, the solar wind was not able to push silicon chondrules outwards very much, due to their large size (compared to gas molecules). Thus, the inner planets are made of rocky silicon, while the outer planets, beginning with Jupiter, are made of volatile gaseous compounds.

The inner rocky planets slowly expanded in size due to falling rocks (and later comets). Eventually, radioactive decay in the Earth (and Mars) increased the inner temperatures of these planets enough that they melted inside, that is, they changed from largely hetorogenous chunks of rock to something more like today's planets. As the inside of the Earth melted, the most dense elements sank to the center. The most common dense element was iron. Thus the Earth got its iron core. Due to the motion of that solid/liquid iron core, the Earth developed a natural magnetic field. That magnetic field deflected the high speed charged particles in the solar wind around the Earth, thus protecting our atmosphere from being blown away. For some reason that I am not aware of, Mars did not develop a significant magnetic field. Thus, over time, Mars lost its atmosphere due to molecular collisions with particles in the solar wind.

I think the best way to answer your question would be to say that Mars got its atmosphere the same way that Earth did. Likely from some combination of comet collisions bringing volatiles from the outer solar system, and from volcanism releasing volatiles that were initially trapped in the rocky Earth. The solar wind acted on Mars' atmosphere over many billions of years, slowly removing it molecule by molecule. It wouldn't have happened right away...it would have taken a very long time to thin Mar's atmosphere significantly.

There...a bit longer than what I intended, but not bad considering what I described.

Another idea

[TheDarkMaster]

I'm pushing the limits of the google translator, but where we go.

I believe Mars was once equal to Earth: Dense enought atmosphere, oceans of water on the surface, and even a magnetic field protecting the atmosphere. But, some day long, long ago this happened, and caused the equivalent of Armageddon on the planet and turned him into what we know today. A "killed" planet.

Re:Page Formatting

[VortexCortex]

What is this new page formatting where things follow you as you scroll called?

PRISM

How can you resist?

[VortexCortex]

Mars is trapped in its orbit and will remain there for the foreseeable future. It will still be there once we have developed the new energy solutions we need on this planet.

What application is demanding the development of new energy solutions? Right now ALL OF OUR EGGS ARE IN ONE BASKET. Solving the extinction problem should be priority #1. You call yourself Sentient?! Get your ass to Mars. Damn, we can't be ANY more blunt than that! The dinosaurs! Think!

So, here you are, with a space program. You've got a HUGE fabulous moon that's easy to see and get to that's got the same chemical composition of your planet, and a nice deep crater at the south pole to hang out in from solar storms. The next planet out has more gravity but has no magnetic field or atmosphere, but it's got resources you can use... PERFECT trial grounds for learning how to survive in deep space. Beyond that, there's a huge asteroid field with abundant resources for building things in space without the gravity tax, including Ceres a dwarf planet made of ice and rock... Ice = water = hydrogen & oxygen... grrrrr. Next we have a HUGE Gas Giant to study gravitational effects without getting burnt by the sun. In the solar system you just happen to find yourself in there are beautiful ringed worlds further out, and There's ice moons and moons full of methane, and... And... AND.

calm, stay calm...

And this puny minded ape wants to JUST SIT THERE?! You let defected pieces of shit like this survive among you?! You'll NEVER solve the Fermi Paradox at this rate!

Re:How can you resist?

[Anonymous Coward]

Please watch less science fiction.
Please learn to distinguish fiction from reality.
Please post less.

Re:How can you resist?

[0111 1110]

I believe evolution will have the same effect on them, ie they won't be any better adapted to long-term survival in space than we are.

Our bodies are not adapted for speed like a cheetah. So we will never travel faster than a human can run. We don't have big teeth. So we can never be predator. Only prey. We don't have wings. So we will never fly. We don't have gills. So we will never swim underwater longer than we can hold our breath. And obviously we will never ever be able to walk on the moon because there is no air there and we need air to survive.

Atmospheric Loss?

[Dereck1701]

This article seems to be alluding to the solar wind stripping Mars's atmosphere away. Wasn't there just a study a few months ago showing that the effects of solar winds on a planetary atmosphere are not nearly as significant as was once believed, and that there is almost no way that the solar wind alone could be responsible for the Martian atmospheres losses. Personally I'd trust that data a lot more as I think it was based on current measurements of the effects of the solar wind on the Martian atmosphere, not extrapolations from microscopic amounts of materials found in Martian meteorites that likely went through extreme events getting here (being blown off of Mars, spending years, decades, centuries and even eons in space, and then atmospheric reentry) that could have altered their chemistry. My two cents on the whole thing is most of the Martian atmosphere is probably still on Mars, tens, hundreds or even thousands of miles below the surface. Most people don't conceive of how narrow a margin we cling to life on this spinning ball of mud floating on a sea of lava. If you took a basketball and laid a single sheet of paper on its surface that width is far more than the area in which humans can survive without supplemental support systems. As the planets interior cooled the atmosphere may have retreated into the crust, on Earth this is prevented the elements in question (water, nitrogen, oxygen) tend to be ejected by Earths interior in a variety of ways (geysers, volcanoes, fissures) because of their tendency to expand when they come into contact with heat. On Mars as the planet cooled the atmosphere could have leaked through fissures and permeable areas in the crust as the internal temperatures were no longer able to keep it near the surface. This could open interesting possibilities for colonization, as to retrieve significant amounts of atmosphere, water and other necessary components future colonists may only need to sink "wells" deep enough to reach those deposits. Microbial life may even have followed these life sustaining elements into the planets crust as they retreated over the eons.

Re:The Creepiest Thing About This Movie.. The Arri

[EzInKy]

Listen to David Icke. He will sound like an absolute fruit loop at first, but more and more of what he says is beginning to make sense.

So you are saying his paranoia is infectious?