New Evidence of Ancient Oceans on Mars

By Nina Bai | November 19, 2008 7:24 am

marsNew data from NASA‘s Mars Odyssey orbiter supports the long-debated theory that Mars once (or twice) had vast frozen oceans on its surface. The location of certain mineral deposits suggests massive erosion and ancient shorelines. A group of researchers now believes Mars had at least two oceans – one about three and a half billion years ago that was 20 times the size of the Mediterranean and a smaller one about two billions years ago. “These were not like the oceans we know,” says [researcher Victor] Baker. “These were transient bodies that existed long enough to accumulate sediment”, but were not present for billions of years of geologic history, as Earth’s oceans have been [New Scientist].

The Mars Odyssey orbiter identified the mineral deposits using a gamma-ray spectrometer, which can detect elements a third of a metre below Mars’s surface. It found enriched potassium, thorium and iron, lying in shoreline-type patterns, where researchers already suspected water used to lie [Canwest News Service]. Until now, however, their suspicions were mainly based on geographical features such as smooth plains surrounded by higher, more rugged terrain. The new data, to be published in Planetary and Space Science, shows minerals heavily concentrated in the soil below the proposed shoreline and less concentrated above, suggesting erosion of sediments into a large body of water. But study coauthor James Dohm says the new evidence isn’t a smoking gun: “It’s consistent with this ocean potential – it doesn’t confirm it, necessarily,” Dohm said. “I think it’s a significant piece of the puzzle” [Tucson Citizen].

Proving the existence of ancient Martian oceans is difficult partly because scientists don’t know exactly what they’re looking for. Unlike Earth’s oceans, Martian oceans would not have had strong tides that pound out shorelines. “On Mars you have smaller moons. You don’t have the tidal forces,” Dohm said, which makes it tough to see shorelines. And because Mars is much colder than Earth, the oceans could have been covered in ice, which would block wave action that creates a distinctive look [Tucson Citizen]. In certain places, volcanic activity could have also created hot springs and a potential environment for extraterrestrial microbes, say the researchers.

The Mars Odyssey has been orbiting the Red Planet since 2001 and scientists hope it will continue sending back data until at least 2010. Earlier this month, scientists reported that NASA’s Mars Reconnaissance Orbiter, a different spacecraft, had found hydrated minerals that indicate the presence of liquid water on Mars about 2.5 million years ago.

Related Content:
80beats: Martian Stones Suggest a More Recent Watery Past
80beats: RIP Mars Phoenix Lander
80beats: In the Dark and the Cold, Mars Phoenix Lander Begins to Shut Down
80beats: Martian Gullies Were Formed by Liquid Water
80beats: 4 Billion Years Ago, Mars Was Wet and Wild
80beats: Mars Water May Have Been Suited for Pickles, Not for Life

Image: NASA (shows potassium concentrations on Mars)



  • Cheesehead024

    I’m amazed that we have this kind of techonology to even achieve these kinds of discoveries. If Mars actually has had bodies of water at some point, who knows what else it could have contained at some point.

  • Kim

    More and more discoveries have led to the concenpt of oceans on mars. Although it can’t be said for sure, I easily believe that the water was once there. The only issue I’m concerned with is why aren’t they there now? If scientists could find sufficient evidence of why the Martian Oceans no longer exist, then it ought to be easier to determine whether or not they were there at all. By working backwards, determination of oceans on Mars can be not only proved but explained.

  • Carter

    Geology is the most revealing science. It’s great we can learn so much about how things got here from the rocks.

  • Wendy

    is it possible that mars has periods of warmer, wetter types of weather like the earth does? goes thru ice age like periods? im not educated enough in this area to put in the correct terms but maybe someone will know what i am talking about.

  • Denitsa

    I think this year can easily be called the year of Mars. It’s surprising how much information we gathered about the Red Planet just in a month or two. And I like it. Because if you think carefully about it, the more we learn about Mars, the more we know about all the planets from Earth type in the Universe. And that’s pretty cool.


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