Mars today is marked by its endless red desert plains. But it was not always so. There was water and it flowed on its surface longer than previously estimated, says new NASA research. The Red Planet rippled with rivers and ponds like Earth billions of years ago, providing a potential habitat for microbial life. That water, however, evaporated as the planet’s atmosphere thinned over time. It was believed that water evaporated about three billion years ago. But two scientists studying data, which the Mars Reconnaissance Orbiter (MRO) has accumulated over the past 15 years, have found evidence that significantly alters the timeline.
Their research revealed that there was liquid water on Mars as recently as 2 to 2.5 billion years ago. Which means water flowed on Mars a billion years longer than previous estimates. The scientists relied on the chloride salt deposits left by the evaporation of meltwater. Certain valley networks on Mars suggested that water flowed there until very recently, but there was no conclusive evidence. The presence of liquid water is confirmed by salt deposits, which are the first mineral evidence.
The findings were published in the open access journal AGU Advances. And they raise interesting new questions, including how long microbial life could have survived on Mars.
Study lead author Ellen Leask and Caltech professor Bethany Ehlmann used data from an MRO instrument called the Compact Reconnaissance Imaging Spectrometer for Mars to map chloride salts in the southern hemisphere of Mars. On a report on the NASA website, Ehlmann said the surprising fact was that the MRO led to new discoveries about the nature and timing of these ancient river-connected salt ponds after more than a decade of providing high-resolution images, stereo, and infrared data. .
NASA’s Mars Odyssey orbiter, launched in 2001, first detected the salt crystals 14 years ago. MRO, which has higher resolution instruments than the Odyssey, has been studying salts since its launch in 2005.