Artist’s rendering of a solar storm hitting Mars and stripping ions from the planet's upper atmosphere.  Credits: NASA/GSFC

NASA’s MAVEN Orbiter Discovers Solar Wind Stripped Away Mars Atmosphere Causing Radical Transformation

Article Updated: 23 Dec , 2015

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NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter mission has determined that ancient Mars suffered drastic climate change and lost its thick atmosphere and surface bodies of potentially life giving liquid water because it lost tremendous quantities of gas to space via stripping by the solar wind, based on new findings that were announced today, Nov. 5, at a NASA media briefing and in a series of scientific publications.

The process of Mars dramatic transformation from a more Earth-like world to its barren state today started about 4.2 Billion years ago as the shielding effect of the global magnetic field was lost as the planets internal dynamo cooled, Bruce Jakosky, MAVEN principal investigator at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder, told Universe Today.

The radical transformation of ancient Mars from a warm world with significant bodies of standing water that could have supported life, to its current state as a cold, arid and desert-like world that’s rather inhospitable to life was caused by the loss of most the planet’s atmosphere as powerful streams of solar wind particles crashed into it and stripped it away due to the loss of the protective magnetic field as the planets core cooled.

“We think that the early magnetic field that Mars had would have protected the planet from direct impact by the solar wind and would have kept it from stripping gas off,” Jakosky told me.

“So it would have been the turn off of the magnetic field, that would have allowed the turn on of stripping of the atmosphere by the solar wind.”

“The evidence suggests that the magnetic field disappeared about 4.2 Billion years ago.”

The period of abundant surface water actively carving the Martian geology lasted until about 3.7 Billion years ago. The loss of the atmosphere by stripping of the solar wind took place from about 4.2 to 3.7 Billion years ago.

Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm.  Credit: NASA

Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm. Credit: NASA

With the release of today’s results, the MAVEN science team has accomplished the primary goal of the mission, which was to determine how and why Mars lost its early, thick atmosphere and water over the past four billion years. The atmosphere is composed mostly of carbon dioxide.

Since water is a prerequisite for life as we know it, determining its fate and longevity on Mars is crucial for determining the habitability of the Red Planet and its potential for supporting martian microbes, past of present if they ever existed.

“The NASA Mars exploration program has been focused on finding water,” said Michael Meyer, lead scientist for the Mars Exploration Program at NASA Headquarters.

“Water is the prime ingredient needed for life. It is a major factor in the climate and for shaping geology. And it is a critical resource for future human exploration.”

NASA’s goal is to send humans on a ‘Journey to Mars’ during the 2030s.

This NASA video shows a visualization of the solar wind striking Mars:

Video caption: Created using data from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, this visualization shows how the solar wind strips ions from the Mars’ upper atmosphere into space. Credits: NASA-GSFC/CU Boulder LASP/University of Iowa

MAVEN arrived in orbit at Mars just over one year ago on Sept. 21, 2014.

The $671 Million MAVEN spacecraft’s goal is to study Mars tenuous upper atmosphere in detail for the very first time by any spacecraft and to explore the mechanisms of how the planet lost its atmosphere and life giving water over billions of years as well as determine the rate of atmospheric loss.

The new MAVEN data have enabled researchers to measure the rate of Mars atmospheric loss of gas to space via the action of solar wind stripping as well as the erosional effect of solar storms.

Based on measurements from MAVEN’s suite of nine state-of-the-art scientific instruments, the solar wind is stripping away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second today, in the form of carbon dioxide and oxygen, said David Brain, MAVEN co-investigator at LASP.

“Most of the stripping [of the Martian atmosphere] by the solar wind at Mars was thought to have taken place very early in the history of the solar system when the sun was much more active and when the solar wind was more intense. So today the rate of loss at Mars is low,” Jakosky said at the briefing.

“Today’s Mars is a cold dry desert-like environment. The atmosphere is thin and it’s not capable of sustaining liquid water at the surface today, it would freeze or evaporate very quickly. However when we look at ancient Mars we see a different type of surface, one that had valleys that looked like they were carved by water and lakes that were standing for long periods of time. We see an environment that was much more able to support liquid water.”

The MAVEN results were published today in nearly four dozen scientific papers in the Nov. 5 issues of the journals Science and Geophysical Research Letters.

I asked Jakosky; How much gas would have been lost from ancient Mars and what is the rough estimate for the ancient rate of loss to arrive at Mars thin atmosphere today?

“For the amount of gas that we think you would have to have been removed – let me start with the current Mars atmosphere which has a thickness of 6 millibars, that’s just under 1% as thick as the Earth’s atmosphere,” Jakosky replied.

“So we think you would have to remove an amount of gas that is about equivalent to what’s in Earth’s atmosphere today.”

“So the rate would have to have been a factor of about 100 to 1000 times higher, than today’s loss of 100 grams per second in order to have removed the gas early in that time period, which is consistent with what the models have predicted that the loss rate would have been back then in early history.”

NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft celebrated one Earth year in orbit around Mars on Sept. 21, 2015.  MAVEN was launched to Mars on Nov. 18, 2013 from Cape Canaveral Air Force Station in Florida and successfully entered Mars’ orbit on Sept. 21, 2014.  Credit: NASA

NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft celebrated one Earth year in orbit around Mars on Sept. 21, 2015. MAVEN was launched to Mars on Nov. 18, 2013 from Cape Canaveral Air Force Station in Florida and successfully entered Mars’ orbit on Sept. 21, 2014. Credit: NASA

What is the solar wind and how does it strip away the atmosphere?

“The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun’s atmosphere at a speed of about one million miles per hour. The magnetic field carried by the solar wind as it flows past Mars can generate an electric field, much as a turbine on Earth can be used to generate electricity. This electric field accelerates electrically charged gas atoms, called ions, in Mars’ upper atmosphere and shoots them into space,” according to a NASA description.

MAVEN is NASA’s next Mars orbiter and is due to blastoff on Nov. 18 from Cape Canaveral, Florida. It will study the evolution of the Red Planet’s atmosphere and climate. Universe Today visited MAVEN inside the clean room at the Kennedy Space Center.  With solar panels unfurled, this is exactly how MAVEN looks when flying through space and circling Mars.  Credit: Ken Kremer/kenkremer.com

MAVEN is NASA’s next Mars orbiter and is due to blastoff on Nov. 18 from Cape Canaveral, Florida. It will study the evolution of the Red Planet’s atmosphere and climate. Universe Today visited MAVEN inside the clean room at the Kennedy Space Center. With solar panels unfurled, this is exactly how MAVEN looks when flying through space and circling Mars. Credit: Ken Kremer/kenkremer.com

MAVEN is just now completing its primary mission and starts the extended mission phase on Nov. 16.

The 5,400 pound MAVEN probe carries nine sensors in three instrument suites to study why and exactly when did Mars undergo the radical climatic transformation.

MAVEN’s observations will be tied in with NASA’s ongoing Curiosity and Opportunity surface roving missions as well as MRO and Mars Odyssey to provide the most complete picture of the fourth rock from the sun that humanity has ever had.

MAVEN thundered to space on Nov. 18, 2013 following a flawless blastoff from Cape Canaveral Air Force Station’s Space Launch Complex 41 atop a powerful United Launch Alliance Atlas V rocket.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

NASA’s MAVEN Mars orbiter, chief scientist Prof. Bruce Jakosky of CU-Boulder and Ken Kremer of Universe Today inside the clean room at the Kennedy Space Center on Sept. 27, 2013. MAVEN launched to Mars on Nov. 18, 2013 from Florida. Credit: Ken Kremer/kenkremer.com

NASA’s MAVEN Mars orbiter, chief scientist Prof. Bruce Jakosky of CU-Boulder and Ken Kremer of Universe Today inside the clean room at the Kennedy Space Center on Sept. 27, 2013. MAVEN launched to Mars on Nov. 18, 2013 from Florida. Credit: Ken Kremer/kenkremer.com

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23 Responses

  1. BlackWolfStanding says:

    Not really new news. It’s been speculated for a number of years now that the solar wind stripped Mars of it’s thick atmosphere. But it’s always good to get scientific evidence to back the theory.

  2. InTheory says:

    What would have caused the Martian core to cool in only 300,000 years. I realize that it’s smaller than the Earth, but our core is still active and molten after 4 ½ billion years but Mars’s was no longer active just 300,000 years after its accretion. Does the Earth being larger and having a Moon really have such a huge effect?

    • FarAwayLongAgo says:

      300 million years, but it is still quick.

    • slicksister says:

      I believe the fact that Mars is smaller and doesn’t have a substantial moon creating tidal flexing and heating of it’s interior, might be a couple of reasons it cooled faster than Earth.

  3. pauloaguia says:

    So this means that even if we could terraform the planet the atmosphere would just be lost to space again.
    Add a step before any terraforming efforts: restore the planet ‘s dynamo…

    • mewo says:

      It wouldn’t disappear overnight. The loss of Mars’s atmosphere would be quick by geological time scales, but long by human time scales. If we can terraform Mars in the first place, we will certainly be able to replenish its atmosphere against solar wind losses.

      • FarAwayLongAgo says:

        If so, why not terraform the Moon? 60% of it is oxygen so there’s plenty of material to replenish a breathable atmosphere with, given all energy in the world.

      • mewo says:

        Absolutely, I think the Moon is also terraformable, so why not? There’s two problems the Moon has that Mars does not, though.

        Days and nights would be inconvenient because of the slow rotation.

        If we gave the Moon an ocean, the tides would be many tens of meters.

  4. Steven says:

    Brings up Venus all over again…. Huge atmosphere but even more intense solar wind….Yes it is a bigger planet and signs of volcanism but no magnetic field and a huge atmosphere. I’ve not heard a solid explanation of why.

    • slicksister says:

      a good effect of global warning? 🙂

      but you’re right. What explains Venus’s atmosphere when it has no moon, no magnetic field, and yet much higher exposure to solar winds?

    • FarAwayLongAgo says:

      Maybe Venus was hit by a giant comet 300 million years ago, when it was resurfaced. Maybe that event brought all the volatiles to form its thick atmosphere. Maybe that stopped its rotation and turned it about and extinguished its magnetic field. Maybe Venus was much more Earth like before.

    • Navneeth says:

      Perhaps in addition to the extreme volcanism and larger size, Venus’ magnetic field could have been lost more recently compared to Mars.

  5. Paul Gracey says:

    Regarding the Venus enigma; could it be that Venus is generating that atmosphere from volcanic sources faster than it is being stripped away?

  6. Vinay says:

    On 28th Sept NASA announced something contradictory to the above announcement? Hope somebody will explain.

  7. battywampus says:

    They should have just listened to Astronomy Cast. Would have saved a lot of monies.

  8. BlackWolfStanding says:

    Having Solar wind strip away an atmosphere is slow by human standards, whose to say Venus’s atmosphere is not being stripped away while we discuss it here? Even if that is happening, we absolutely have not had enough time nor missions to determine if that is or is not the case.

  9. According to Hindu cosmology, Earth remains entirely covered by water for a period of 864,000 years before the start of each Manvantar, and for that same period of time after the completion of each Manvantar. I don’t know if anything is said about the other planets. In Habitable Planets For Man Stephen H. Dole says that such a planet could hardly be habitable for human beings, and that the present volume of surface water would have to be four times greater for all of the continents to be flooded.

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