When most people think of an oasis, they think of emerald pools contrasting the dusty hues of a surrounding desert. One might even picture lazy palm trees dipping their fronds to give shade to the weary desert traveler.
What would an oasis on Mars look like, though? Thanks to NASA’s Curiosity Rover, researchers think that they have discovered the remnants of an ancient Martian oasis, Futurism reports.
Red Planet Paradise
Curiosity is currently trekking up Mount Sharp in Mars’ Gale Crater. In a paper published in Nature Geoscience, the Curiosity scientists paint a picture of what the crater may have looked like over three billion years ago. That picture includes streams cascading down the walls of the crater. These rivulets then pooled in the bottom as salty ponds and lakes which seemed to dot the crater floor at random.
However, these streams and lakes weren’t permanent. Researchers believe that the crater went through wet and dry times—much like deserts on Earth. The authors of the study likened the area on Mars to South America’s Altiplano high-desert region.
To make the discovery, scientists analyzed samples collected by the rover. These rocks contained mineral salts. The deposits point to the existence of shallow, briny pools that existed in the crater billions of years ago. Fluctuations between wet and dry spells could have taken place over millions of years as Mars transitioned into the cold, dry place that it is today.
How Long was Mars Habitable?
How and when this transformation took place is what scientists want to know. Answers to this question may come as Curiosity continues to an area called the “sulfate bearing unit.” Researchers believe that this area formed during a drier period in Mars’ history. Of course, this is very different from the low-lying Mount Sharp where Curiosity discovered evidence of a wetter time.
Mount Sharp became an area of inquiry for Curiosity because of its geology. The mountain sits at the center of the 100-mile-wide Gale Crater. Over time, the impact crater filled in with sediment carried by wind and water. That sediment eventually hardened over the course of millions of years. The wind then eroded the layered rock, leaving lofty Mount Sharp towering over the crater. The mountain’s slopes expose those layers, giving snapshots of different eras in Mars’ geologic history.
“We went to Gale Crater because it preserves this unique record of a changing Mars,” lead author William Rapin of Caltech said. “Understanding when and how the planet’s climate started evolving is a piece of another puzzle: When and how long was Mars capable of supporting microbial life at the surface?”
Knowing how long Mars contained liquid water on its surface is key to knowing whether the red planet could have once supported life. If Mars had water for a relatively short period of time, life may not have had the chance to take hold. By contrast, if the water stood still for hundreds of millions, or even billions, of years, life could have evolved. Curiosity will continue its mission to find out.