Scientists Explain How Mars Lost Its Oceans... And Where The Water Might Have Gone
We've long known that Mars once flowed with water through rivers, lakes and maybe even oceans. We've also long known that where there's water, there's life.
Just how long life was sustainable on The Red Planet has been called into question though, as a new study, published in Nature, suggests that Mars' surface had all but dried up some 3.7 billion years ago, under a billion years after the planet formed.
"Although some of the water on Mars was lost to space via photolysis following the collapse of the planet's magnetic field, the widespread serpentinization of Martian crust suggests that metamorphic hydration reactions played a critical part in the sequestration of the crust," the study concluded.
Simply put: though some of the planet's water was likely lost to space, Mars' rocky crust was so thirsty that all water it absorbed altered its chemistry.
"We're suggesting that, irrespective of these two factors, Mars, by virtue of its chemistry, was doomed from the start," the study's lead author Dr. Jon Wade said. "It was likely inevitable that its water would have been sucked back into its mantle."
Wade thinks that this process began with the shutdown of the planet's Internal Dynamo, a mechanism that creates a planet's magnetic field from the inside. Without that, the loss of a magnetic field was indeed inevitable. This meant Mars no longer had protection from the solar wind, and the rays took a toll on its atmosphere as a result.
The serpentinization process also meant that water reaching Mars' thirsty rocks changed their chemistry, creating hydrous minerals due to the planet's Iron-rich mantle. "On early Earth, hydrated surface rocks would tend to 'float' on the surface until they dehydrate, providing a return path of water to the surface," added Wade. "However, on [ancient] Mars, these hydrated rocks, bearing dense minerals, may sink into the mantle and act to lock up the water, removing it for good."
While this may come as a blow to those of us who want to think that Martian civilization was long and prosperous, the .9 billion years that Mars supported life doesn't rule out the possibility of a society that lasted longer than humans on Earth have been around.