NASA's MAVEN spacecraft has found that solar wind and radiation are responsible for stripping away most of the Martian atmosphere, and that the rate of atmosphere loss was higher earlier in the history of the solar system:
Solar wind and radiation are responsible for stripping the Martian atmosphere, transforming Mars from a planet that could have supported life billions of years ago into a frigid desert world, according to new results from NASA's MAVEN spacecraft. "We've determined that most of the gas ever present in the Mars atmosphere has been lost to space," said Bruce Jakosky, principal investigator for the Mars Atmosphere and Volatile Evolution Mission (MAVEN), University of Colorado in Boulder. The team made this determination from the latest results, which reveal that about 65 percent of the argon that was ever in the atmosphere has been lost to space. Jakosky is lead author of a paper on this research to be published in Science on Friday, March 31.
In 2015, MAVEN team members previously announced results that showed atmospheric gas is being lost to space today and described how atmosphere is stripped away. The present analysis uses measurements of today's atmosphere for the first estimate of how much gas was lost through time. Liquid water, essential for life, is not stable on Mars' surface today because the atmosphere is too cold and thin to support it. However, evidence such as features resembling dry riverbeds and minerals that only form in the presence of liquid water indicates the ancient Martian climate was much different – warm enough for water to flow on the surface for extended periods.
It's time to stop it.
YouTube video attached to the article, and infographic. Also at University of Colorado Boulder.
Mars' atmospheric history derived from upper-atmosphere measurements of 38Ar/36Ar (DOI: 10.1126/science.aai7721) (DX)
Related Stories
Another study has cast doubt on the habitability of an Earth-like exoplanet in the "habitable zone" of a red dwarf, in this case Proxima Centauri specifically:
At only four light-years away, Proxima b is our closest known extra-solar neighbor. However, due to the fact that it hasn't been seen crossing in front of its host star, the exoplanet eludes the usual method for learning about its atmosphere. Instead, scientists must rely on models to understand whether the exoplanet is habitable.
One such computer model considered what would happen if Earth orbited Proxima Centauri, our nearest stellar neighbor and Proxima b's host star, at the same orbit as Proxima b. The NASA study, published on July 24, 2017, in The Astrophysical Journal Letters [DOI: 10.3847/2041-8213/aa7eca], suggests Earth's atmosphere wouldn't survive in close proximity to the violent red dwarf.
[...] In Proxima Centauri's habitable zone, Proxima b encounters bouts of extreme ultraviolet radiation hundreds of times greater than Earth does from the sun. That radiation generates enough energy to strip away not just the lightest molecules — hydrogen — but also, over time, heavier elements such as oxygen and nitrogen.
The model shows Proxima Centauri's powerful radiation drains the Earth-like atmosphere as much as 10,000 times faster than what happens at Earth.
Previously: "Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri
Proxima b May Have Oceans
Researchers Suffocate Hopes of Life Support in Red Dwarf "Habitable Zones"
Proxima B Habitability Study Adds Climate Model
Related: MAVEN Results Find Solar Wind and Radiation Responsible for Stripping the Martian Atmosphere
One of the primary drivers for the distinct lack of a Martian atmosphere is believed to be the loss of atmospheric molecules that are stripped away by the passing solar wind. A strong planetary magnetic field would divert the solar wind around the planet and protect the Martian atmosphere. The MAVEN spacecraft confirmed this is happening, and some interesting ideas have been floated to mitigate the effect.
A recent paper published in JGR: Space Physics used Magnetohydrodynamic (MHD) models to investigate the magnitude of the effect on atmospheric retention that a magnetic field would have on Mars and found a very interesting result. Their models confirmed that the rate of atmospheric loss was six times higher for a planet with no magnetic field compared to a planet with a strong magnetic field; however, they found the highest rate of atmospheric loss was actually when there was a weak magnetic field.
But the highest rate of atmospheric ion loss was with a weak magnetic field—6 times faster than with no magnetic field at all. The team found the reason was the magnetic field lines, which guide the motion of charged particles, were easily blown back by the solar wind, creating a path for these ions to escape into space above Mars's nightside. This means that instead of providing a small measure of protection, Mars's remnant magnetic field could actually have sped the planet's transformation into the cold, barren world it is today.
Research Paper: Sakata, et al., Effects of an Intrinsic Magnetic Field on Ion Loss From Ancient Mars Based on Multispecies MHD Simulations, Journal of Geophysical Research: Space Physics, https://doi.org/10.1029/2019JA026945, 2020
(Score: 0) by Anonymous Coward on Sunday April 02 2017, @03:00PM (3 children)
The only commentary besides links was "it's time to stop it.". Stop the atmospheric loss? Stop trying to send humans there?
Cause I've heard some of the ideas of how to protect the atmosphere and they sound so energy intensive that I don't think they're a very good idea.
(Score: 4, Insightful) by ticho on Sunday April 02 2017, @03:16PM (1 child)
Isn't it obvious? A legislation needs to be passed to make martian atmospheric loss illegal. We will most likely also need a War on Martian Atmospheric Loss.
Write your congressman, folks, the time is ticking.
(Score: -1, Flamebait) by Anonymous Coward on Monday April 03 2017, @04:16AM
WTF with insightful? These are obvious joke comments, is this insightful cause it makes you climate deniers feel vindicated somehow?
(Score: 3, Insightful) by maxwell demon on Sunday April 02 2017, @06:00PM
Stop the solar wind and radiation, of course. Switch off the sun, it's proven dangerous.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by Lagg on Sunday April 02 2017, @04:55PM
My understanding of this was that sputtering is like a cosmic bitchslap that tears away hair. Our core basically acts as its own magnetic shield to deflect most of the bombardment. It's going to turn the planet into something like Mars when the core cools I guess. But we'll probably have other things to worry about by that point.
http://lagg.me [lagg.me] 🗿
(Score: 2) by kaszz on Sunday April 02 2017, @05:38PM (5 children)
Thus we shall not terraform Mars until there's a workable technology that can make sure the new atmosphere stays. Otherwise it would just be a giant waste that perhaps can't be attempted again.
Perhaps in the future it will be possible to power giant wires around the planet with nuclear plants as a artificial substitute for the missing hot rotating core.
(current through conductor equals magnetic field)
(Score: 2) by NotSanguine on Sunday April 02 2017, @06:59PM (4 children)
Just last month, folks over at NASA proposed [phys.org] a magnetic shield to be located at Sol/Mars L1. More discussion can be found here [stackexchange.com].
Solar energy could certainly power such a shield.
Way back in 2008, scientists at Japan's NIFS looked at the feasibility of a terrestrial geomagnetic shield using superconducting rings [nifs.ac.jp] [PDF].
Again, solar energy might well be sufficient.
Even though the basic technology is within out capabilities right now, building such devices at Sol/Mars L1 or on the surface of Mars would entail logistical and engineering challenges which are well beyond our current capabilities.
So we can't do it now, but it's not too much of a stretch to think that we will be able to do so in the foreseeable future, assuming we don't die off or destroy our civilization first.
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 0) by Anonymous Coward on Monday April 03 2017, @12:04AM (2 children)
Why not just make the entire planet a giant metal shell that holds the atmosphere and remaining gasses in as we slowly heat it up. Added benefit is the metal shell's conductive nature would help dissipate hotspots to keep the entire planet uniformly warm (or cold, I haven't done any calculations on how much heat it would absorb, insulate, radiate.) Key point is: We were going to build domes to start anyway, why not kick it up a notch and just build a planet spanning shell instead?
(Score: 2) by NotSanguine on Monday April 03 2017, @12:34AM (1 child)
Why not just make the entire planet a giant metal shell that holds the atmosphere and remaining gasses in as we slowly heat it up. Added benefit is the metal shell's conductive nature would help dissipate hotspots to keep the entire planet uniformly warm (or cold, I haven't done any calculations on how much heat it would absorb, insulate, radiate.) Key point is: We were going to build domes to start anyway, why not kick it up a notch and just build a planet spanning shell instead?
Instead of doing heat absorption calculations, why don't you calculate how much metal would be required for that tiny increase in size of a "dome." Enough to enclose the planet.
Don't forget the infrastructure required to support such a sphere around Mars extended out at least a few hundred kilometers for the atmosphere.
I'm sure the materials, energy and engineering difficulty would be much, much less with your idea than a dipole shield or a ground based magnetic field generator. You wouldn't even need to generate a magnetic field. You're brilliant!
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 2) by kaszz on Monday April 03 2017, @03:07PM
Oops.. didn't think of that :-)
(Score: 2) by kaszz on Monday April 03 2017, @03:05PM
I think the capabilities will come when extraterrestrial/asteroid mining takes off and nuclear energy takes another leap. I suspect the main benefit from mining outside earth will be the enabling of gigantic projects outside earth.
(Score: 2) by Entropy on Sunday April 02 2017, @06:02PM (2 children)
This is clearly more evidence to support man made climate change/global warming. It's time to stop it.
(Score: 2) by butthurt on Monday April 03 2017, @01:49AM
LOL, yes.
Mars's atmosphere is about 100 times thinner than Earth's. Without a "thermal blanket," Mars can't retain any heat energy. On average, the temperature on Mars is about minus 80 degrees F (minus 60 degrees C).
-- http://www.space.com/16907-what-is-the-temperature-of-mars.html [space.com]
(Score: 0) by Anonymous Coward on Monday April 03 2017, @04:19AM
I would have thought this was satire if I hadn't seen the author post highly questionable comments before.
(Score: 0) by Anonymous Coward on Sunday April 02 2017, @08:47PM
Think of the (future) Martian children! Stop atmospheric loss today!
(Score: -1, Troll) by Anonymous Coward on Sunday April 02 2017, @11:55PM
They've been studying earth's atmosphere since 1989 and they have fought the science establishment to disprove the sun has anything to do with ... well, anything.
In this world of noble cause corruption: its the CO2 that is the culprit. Ignore direct measurements and opt for 'proxy' measurement.
If the sun is measured to effect the climate and atmosphere of Mar's. Then why isnt it effecting earths ;)
(Score: 2) by Phoenix666 on Monday April 03 2017, @11:12AM (1 child)
So what happened to the old Martian atmosphere that was stripped away by the solar wind? Was it accelerated on a one-way trip to Alpha Centauri, or did it re-accrete in the asteroid belt or around Jupiter, such that we can recapture it and tow it back to Mars so it can have an atmosphere again? I don't know how much material is in the asteroid belt off the top of my head, but I bet it's a lot and we could plunk some of it down on Mars to re-supply it with water and other tasty elements.
Washington DC delenda est.
(Score: 1) by khallow on Monday April 03 2017, @02:54PM