Planetary Scientists Discover That Mars Underwent a Great Oxygenation Event Billions of Years Ago

The blue-toned rocks in the upper-left of the image are depleted in iron because it was removed during weathering on ancient Mars. This is geological evidence that iron was lost from the rocks in reduced conditions. Credit: The University of Hong Kong

Both Earth and Mars currently have oxidizing atmospheres, which is why iron-rich materials in daily life develop rust (a common name for iron oxide) during the oxidation reaction of iron and oxygen. The Earth has had an oxidizing atmosphere for approximately two and a half billion years, but before that, the atmosphere of this planet was reducing – there was no rust.

The transition from a reduced planet to an oxidized planet is referred to as the Great Oxidation Event or GOE. This transition was a central part of our planet’s evolution, and fundamentally linked to the evolution of life here – specifically to the prevalence of photosynthesis that produced oxygen. Planetary geologists at HKU have discovered that Mars underwent a great oxygenation event of its own – billions of years ago, the red planet was not so red.

The discovery was published recently in Nature Astronomy in a paper led by research postgraduate student Jiacheng LIU and his advisor Associate Professor Dr. Joe Michalski, both affiliated with the Research Division for Earth and Planetary Science and Laboratory for Space Research. The researchers used infrared remote sensing and spectroscopy to measure the molecular vibration of the material on the Martian surface from orbit, in order to reveal the mineralogy and geochemistry of ancient rocks on Mars. Through detailed comparisons of infrared remote sensing data and data collected in the laboratory here on Earth, the team showed that ancient rocks on Mars exposed at the surface had been weathered under reducing conditions, indicating a reduced atmosphere did exist.

A 3-dimensional view of weathered bedrock shows the exposure of Fe-rich red rocks beneath Fe-depleted blue-toned rocks in a crater wall. Credit: The University of Hong Kong

Many people are aware that Mars is cold and dry now, but ~ 3.5 billion years ago, it was warmer and wetter. It was warm enough to allow the formation of river channels, lakes, and minerals that formed by interaction with water. Scientists who have used mathematical models to constrain the conditions of an early Martian atmosphere, have concluded that greenhouse warming occurred, but they also concluded from their models that the greenhouse must have included reduced gases rather than carbon dioxide, implied that a reducing atmosphere might have existed. Yet until now, there has not been any evidence that the reduced atmosphere of early Mars actually occurred. This work indicates that it did exist.

This project involved detailed infrared remote sensing of Mars, using infrared spectroscopy to map minerals in exposed, weathered rock units. The work was built on detailed analysis of weathered volcanic rocks in Hainan Island in southwestern China, where thick sequences of basalt, similar to volcanic rocks on Mars occur. Jiacheng Liu analyzed the altered rocks systematically using infrared spectroscopy in the laboratory and produced a paper on that research published recently in Applied Clay Science.

“Jiacheng has carried out a truly excellent PhD project, built on careful analysis in the laboratory and application of those laboratory results to remote sensing of Mars,” Dr. Michalski commented, “Jiacheng has built on his detailed work on samples from Hainan Island to show that similar mineralogical trends occurred in rocks on Mars.”

Assistant Professor Dr. Ryan MCKENZIE from Research Division for Earth and Planetary Science is also impressed by these findings. “This is a rather remarkable study with findings that will significantly impact how we understand the early evolution of terrestrial planets and their surface environments. The transition from a reducing to oxidizing atmosphere on Earth ~2.5 billion years ago was only possible because of the existence of life, as oxygen is a waste product of metabolic processes like photosynthesis. Without microbes producing oxygen, it would not accumulate in our atmosphere, and we could not be here. While there are certainly differences in the local conditions Mars and Earth have been subjected to during their evolutionary histories, my mind can’t help but start thinking about what Jiancheng’s results may mean for a potential early Martian biosphere,” Dr. McKenzie remarked.

As China’s first mission to Mars Tianwen-1 is underway – has successfully arrived in Mars orbit on February 10 and set to land on Mars in May 2021, scientists are preparing for an exciting year of Mars exploration and discovery. This work demonstrates how spectroscopy and remote sensing lead to fundamental discoveries of significant importance for understanding Mars’ history. As we begin to understand the most ancient history of Mars, researchers are ready to directly search of any signatures that life might have once existed on ancient Mars, and HKU plans to be at the center of this great scientific adventure.

Reference: “Anoxic chemical weathering under a reducing greenhouse on early Mars” by J. Liu, J. R. Michalski, W. Tan, H. He, B. Ye and L. Xiao, 11 February 2021, Nature Astronomy.
DOI: 10.1038/s41550-021-01303-5

About the Research Division for Earth and Planetary Science and the Laboratory for Space Research at HKU
The Research Division for Earth and Planetary Science and the Laboratory for Space Research specializes in applications of traditional Earth and environmental science techniques and skills for modern space science challenges. Dr. Joe Michalski operates the Planetary Spectroscopy and Mineralogy Laboratory at HKU and is the Deputy Director of the Laboratory for Space Research.

MarsPlanetsPopularThe University of Hong Kong
Comments ( 41 )
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  • Jeff

    Liars….How can they calculate something that long ago? More BS for the dumbed down masses to lap up. Fake space and Mars in really the Arizona Desert..🤣🤣🤣 Lmbo

  • Jeffery

    Liars…

  • Boris

    I see the Bible thumpers are very worried there might have been or might still br life on Mars.

  • Kit

    If it’s fake jeff why are they lying and don’t give me the if they can lie about this they can lie about anything rubbish what would be the point in this extremely expensive and elaborate lie I’m one for conspiracy but that’s just stupid fair play there might be an Illuminati but space isn’t real pull the other one 🙄😂 flat earther i guess watch the netflix curve documentry you may learn something 😉

  • DJ

    Jeff. You are a hater. You should go back in underground world you came from. Seems about as appropriate as your statments.

  • Bill

    Jeff: You are not intelligent enough to even read this, go back to the gym

  • Steve

    When a scientist draws a conclusion about what happened on another planet billions of years ago, he may eventually be proven wrong, but that doesn’t make him a liar.

  • Moses watyekele

    What if tbere is life on planet mars but unseen with our naked eyes

  • Brainwashed mass member

    Hahah Jeff you crack me up. I have a friend who believes this wholeheartedly so I know you are probably the same. Faking space is easy right, just build a giant firmament, no problems. I guess meteors are just bits that fall off it.

  • Guy

    Jeff , why ? Jeff , come one man! Why?

  • Old Bill

    Is it possible that the NASA people just might discover something from Mars that could become useful in some of Earth’s problems? Like maybe global warming, or ….?

  • FIREYEYEDWOLF

    Ancient Sumerian texts describe a war between two planets. The winners won by sending a weapon to the original planet to dry up the water and turn the planet red. Elon might find out someday, but will he tell the conspiracy nuts? HA! 🤷‍♂️

  • Ed.

    Jeff, the smart people don’t have the time, energy, or crayons to explain all this to you.

  • Nerd

    I’m so confused by the title. The article states that Mars has had an anoxic atmosphere.

  • Dr. Ken Towe

    “The Earth has had an oxidizing atmosphere for approximately two and a half billion years, but before that, the atmosphere of this planet was reducing – there was no rust.”

    That is completely wrong. There is strong mineralogical evidence of hematite in rocks as old as 3.8 Byr-ago. Indeed, the GOE theory requires oxygen to oxidize the ferrous iron in the oceans that would supposedly keep the early atmosphere reducing and form banded-iron ores.
    The rocks on Mars are billions of years old and the surface iron is hematite. There are now theories that the early oceans on Mars might have left oxygen behind. That would not be anoxic. Models are not evidence until their assumptions are confirmed.

  • George

    Chill out! It is a scientific paper; a THEORY!

  • Tim

    Everyone admonishing Jeff… he said one word and he’s getting attention because you think he is naughty. Is he? Likely a troll. If you are so intelligent then why waste your time? Comminicate on his level.

    Jeff: scientific hypothesis, soon to be fact.

    See? Too much effort.

    I find it fascinating that either we are wrong about biomarkers, or there can be non-life causes of large scale atmospheric oxydization, or there was life on Mars when it had substancially more atmosphere… I will be patient for the conclusion but I welcome it.

  • eeeuughhh

    lol troll spotted, or bible retard.

  • Dave

    Jeff, you said it perfectly “How can the calculate something that far back?” That let’s everyone know this is a topic beyond your intellectual comprehension. Just because you don’t understand it doesn’t mean it is fake. You might want to educate yourself on the different geological dating methods.

  • Osagie

    May God save you all, humanity try to stop communication between God and Human, Remember when life was ( 1 1 ) a first word was say from our creator, from that communication we began to understand different things away from God. All of you all. ( No body will stop communication from God to humanity ) the beginning was 1.

    The question I ask? ” Was you there at the beginning? All is lie

  • Danny

    Absolutely Awesome we may actually figure it out with a little help from our GOOD friends.

  • Brianna Alden

    “I don’t understand these scientific processes, and im the smartest person in the world. So, obviously they are lying.”

    -jeff

  • Smiley

    Jeff be careful what you say online. That is a nice red truck you have.

  • Not Jeff

    Are you guys addressing Jeff or Jeffrey? I’m confused… lol

  • Not Jeff

    Are you guys addressing Jeff or Jeffery? I’m confused… lol

  • hi

    hi. quick q: Wheres Jeff?

  • Mark Greenwood

    Molecular Oxygen!

  • Vomitman

    Jeff, I invite you to join our flat Earth society science denying cult. You would fit right in.

  • Brian

    Jeff,
    Planetary science involves a lot of things. Meteorology. Geology. Biology. Chemistry. It goes on. I find it disturbing and feel really sorry for you that you just cannot find any wonder or amazement with these findings. If you honestly think that Mars rovers are in the Arizona desert, well I think that the Chinese would have a pretty hard time landing their probe there… Maybe you should go back to school.

  • James

    I would love to see which conspiracy source Jeff got that from

  • King 24

    I feel our friend jeff is a bit dumb, and most prolly a school drop out, dont hate him 😔😔

  • Rick

    So, china has also an ambition of exploring Mars? It might later on claim Mars as a chinese territory!

  • Bo

    Jeff, if you went to school and studied, you would know the answer to your own q.

  • Thomas

    I like how Jeff has another account- Jeffery

  • Thomas

    The question I ask Osagie? Was you ever in schoolin?

  • Droneman88

    Who else thinks jeffery is also Jeff… 🖐️🖐️🖐️

  • R Dunn

    ALL OF YOU COMMENTERS: Why is it that when someone disagrees with another’s opinion that they resort to name calling and act like kindergartners? Even if Jeff is a flat-earther, what makes it okay for anyone to assume they know anything about him personally to say things like “go back to the gym”, or that he is stupid. At least he gave some background on WHAT his belief is anyway, the rest of you were just looking to troll the internet for someone to beat up.
    I’ll say this of this argument: WHO CARES IF MARS ONCE HAD LIFE?! Because it doesn’t now, EARTH DOES, HOWEVER, and what we NEED TO DO is stop acting like it would be so easy for us to pack up our planet and hit the cosmos and become a multiplanetary species, ESPECIALLY with regards to Mars, because wether or not it held life does not mean it would be capable of SUSTAINING IT, without having to do all kinds of MASSIVE amounts of terraforming so we could change the atmosphere, oh, did anyone mention that Mars doesn’t have a real atmosphere and that it is -200° and NONE OF THIS MATTERS ANYWAY BECAUSE WE WILL ALL BE DEAD BY OUR OWN HANDS BECAUSE WE COULD NOT GET “IT” WIRED TOGETHER ENOUGH TO FOCUS ON HOW WE CAN SAVE OUR OWN PLANET. Instead, we got an elitist bunch of holier than thou m&fRs pointing fingers at each other and taking low jabs at each others backs. No wonder the aliens of the bible came back to destroy us. We are definitely not worthy of “gods” compassion, and we are definitely not worthy of being taken seriously by any other entity that might be out there in the heavens – I mean, who’s going to take a planet seriously that is filled with angry little hairless half apes?
    I have a tip, consider this:
    What if all sides of this argument were all as equally right as they were wrong? Except for flying spaghetti monster which is just ludicrous; but in order to know the truth, all those opposing sides would have to come together with one common interest and they would have to work together to figure it out?
    What if you all stopped being so obtuse and unforgiving and shallow and petty and close minded and quit with the endless parade of bigots? Because this article was about Mars, not wether earth was flat, or God exists, or wether the homeboy Jeff is an armchair warrior of the amateur basketball league on weekends, or wether or not you feel so much more entitled than the rest of us to dictate a narrative that has NOTHING TO DO WITH THE SUBJECT OF THE ARTICLE.
    Personally, I feel as though this article deserved a 2/5 star rating; and that is because the author was really reaching in order to pull some credible evidence together for the argument about life on mars.
    Here’s my conclusion:
    WHO GIVES A F*CK. WHAT ABOUT LIFE ON EARTH.
    Shame on you all for resorting to the antics of a grade schooler, like you are all fighting to grab the pretty teachers attention so you can all give her the same exact apple.

  • Pat

    From the comments, quite a few people do not know the physics of spectroscopy, used in many different applications on earth and on satellites as well. Environmental and geologic sciences use this all over the place as test methds and tools of science. Looks like quite a few of poorly educated people commenting on science, they know way could understand. Good science and indeed an indicator of something hard testing on Mars might create more information on this area of research.

  • Damian

    Jeff, Man go back to school. Scientists date minerals because minerals are made up of elements, i hope you know that. Elements have something called a half-life which is half of the time it takes for these elements to decay. They date these rocks and other stuff judging off of how many half lifes an element has gone through since when it finishes half lifes it starts to change into another element that then has a half life and so forth. Through experiments here on earth we can know how long individual elements half lifes are and therefore we can take that information to date the same elements on mars and doing so date the rocks, stuff in the air, water, and anything else they find. Hope i could be of help.

  • Klanka

    So they are saying there was life on Mars. That’s the only way that much oxygen could occur.

    Where’s the evidence of life?

  • Shaun

    Honestly who cares. I think most people commenting are a fraction to sensitive. I ask you all this; will it effect your lives personally?