The water regarded as accountable for Mars’ intriguing seasonal darkish streaks could also be coming from very deep underground, a brand new research suggests.
These streaks, referred to as recurring slope lineae (RSL), seem on some Martian slopes throughout heat components of the yr. Scientists have posited that RSL are brought on by transient flows of briny water at, or simply beneath, the Pink Planet’s floor.
“We recommend that this is probably not true,” research co-author Essam Heggy, a analysis scientist on the College of Southern California (USC) and NASA’s Jet Propulsion Laboratory in Pasadena, mentioned in a press release. “We suggest another speculation that they originate from a deep pressurized groundwater supply, which involves the floor shifting upward alongside floor cracks.”
Associated: Photos: The Search for Water on Mars
And Heggy does imply deep: The aquifers feeding the RSL seemingly lie about 2,460 toes (750 meters) underground, in response to the brand new research.
Heggy and lead writer Abotalib Z. Abotalib, a postdoctoral analysis affiliate at USC, studied imagery captured by NASA’s Mars Reconnaissance Orbiter (MRO), which found RSL again in 2011. They regarded particularly at three RSL-bearing craters, in addition to streaks within the big canyon complicated Valles Marineris.
Abotalib and Heggy discovered a spatial correlation between RSL and tectonic and impact-related faults — options that would facilitate the motion of water from deep underground to the floor.
The duo additionally modeled warmth stream within the Martian subsurface and studied underground water motion in desert areas right here on Earth. These numerous traces of analysis point out that RSL water might be coming from deeply buried briny aquifers, the researchers mentioned.
“The expertise we gained from our analysis in desert hydrology was the cornerstone in reaching this conclusion,” Abotalib said in the same statement. “We now have seen the identical mechanisms within the North African Sahara and within the Arabian Peninsula, and it helped us discover the identical mechanism on Mars.”
Their proposed rationalization additionally explains the seasonality of RSL.
“The system shuts down throughout winter seasons, when the ascending near-surface water freezes inside fault pathways, and resumes throughout summer season seasons when brine temperatures rise above the freezing level,” the researchers wrote in the new study, which was printed final week within the journal Nature Geoscience.
If Abotalib and Heggy are proper, Mars’ deep groundwater system is extra intensive than beforehand thought. Final yr, Europe’s Mars Categorical orbiter discovered proof for a big subsurface lake near the planet’s south pole, however indicators of aquifers at decrease latitudes have been missing so far.
The brand new research is way from the final phrase on RSL, nonetheless. For instance, not everybody thinks the streaks are certainly proof of liquid water; some scientists regard dry landslides as a more likely explanation. And there may very well be multiple RSL-formation mechanism working on Mars, Abotalib and Heggy famous.
Mike Wall’s e book concerning the seek for alien life, “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), is out now. Comply with him on Twitter @michaeldwall. Comply with us on Twitter @Spacedotcom or Facebook.