Curiosity rover finds evidence of Mars’ ancient salty lakes

Oct 7, 2019, 11:51 AM
NASA's Curiosity rover has found sediments containing sulfate salt in Gale Crater, a vast, dry anci...
NASA's Curiosity rover has found sediments containing sulfate salt in Gale Crater, a vast, dry ancient lake bed on Mars, suggesting the crater once held salty lakes.

(CNN) — Since it landed on Mars in 2012 NASA’s Curiosity rover has been exploring Gale Crater, a vast, dry ancient lake bed with a mountain at its center. Now, Curiosity has found sediments containing sulfate salt in the crater, which suggest it once held salty lakes.

A range of salts have been found on Mars in different locations. Researchers interpret these as evidence of ancient brines. Salty water formations seemed to increase on the Martian surface as the planet transitioned to an arid climate 3.5 bullion years ago.

The new detection of sulfate salts came from sedimentary rocks dated to between 3.3 and 3.7 billion years ago. Curiosity has analyzed other, older rocks on Mars and didn’t detect these salts in them.

Researchers believe the salt is evidence of the crater’s lake evaporating in the Red Planet’s arid environment. They also believe studying younger rocks in the future could shed more light on how the Martian surface dried out.

Gale Crater was created by an ancient impact, then filled in with sediment layers over time. Mount Sharp, the mountain at its center, was created by wind erosion of the hardened sediment layers. Those same layers act like chapters in the history of Mars and provide clues to its environment at each point in time.

At the time the sulfate salts were present, lakes were probably scattered across the crater floor, fed by streams in the crater walls. Over time, the streams would overflow and then evaporate, trapped in a repetitive cycle taking place over millions of years.

The findings were published Monday in the journal Nature Geoscience.

“We went to Gale Crater because it preserves this unique record of a changing Mars,” said William Rapin, lead study author at the California Institute of Technology. “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?”

The sulfate salts represent a different finding from Curiosity’s evidence of freshwater lakes in the foundation of Mount Sharp back in 2015. These new salts were actually found in a section of rocks called “Sutton Island.” Curiosity visited the 500-foot-tall formation in 2017. At the time, they noticed mud cracks, delineating arid periods. But the salts also provide new evidence for brines.

Pure salt is usually left behind when a lake dries and disappears, but these are mineral salts mixed in with sediment. The researchers believe this means that the salts crystallized in a wet environment beneath the briny ponds.

One comparison on Earth is the Altiplano, a high plateau in South America where saline lakes are fed by mountain streams and rivers and influenced by climate shifts.

“During drier periods, the Altiplano lakes become shallower, and some can dry out completely,” Rapin said. “The fact that they’re vegetation-free even makes them look a little like Mars.”

Curiosity’s evidence over the years is contributing to a picture of Mars’ past climate, which went through wet and dry cycles.

“As we climb Mount Sharp, we see an overall trend from a wet landscape to a drier one,” said Ashwin Vasavada, Curiosity Project Scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

“But that trend didn’t necessarily occur in a linear fashion. More likely, it was messy, including drier periods, like what we’re seeing at Sutton Island, followed by wetter periods.”

Earlier in its exploration, Curiosity found flat sediment layers. Now, it’s exploring larger rocks that could have formed due to wind and water forces.

“Finding inclined layers represents a major change, where the landscape isn’t completely underwater anymore,” said Chris Fedo, University of Tennessee researcher of sedimentary layers. “We may have left the era of deep lakes behind.”

™ & © 2019 Cable News Network, Inc., a Time Warner Company. All rights reserved.

Today’s Top Stories

All News

supreme court pictured, its new term has started and will hear new cases...
Aimee Cobabe

U.S. Supreme Court refuses to hear Utah case involving bump stocks

A Utah court case involving bump stocks will not be heard by the U.S. Supreme Court. The court declined to say why it won't take up the case.
19 hours ago
The Book of Mormon Art Catalog offers users a variety of ways to conduct specific searches and to b...
Devin Oldroyd

Book of Mormon digital visual art catalog launches Monday

A digital catalog of visual art inspired by the Book of Mormon became available on Oct. 3. It features more than 2,000 pieces.
19 hours ago
Mosquitos at a Utah lab are pictured....
Britt Johnson

Uptick in mosquitos in Utah caused by recent weather and temperatures

Mosquitos in Utah have seen a growth in population thanks to recent weather. While aggressive, they are not the disease-carrying breed.
19 hours ago
Arctic Monkeys pictured performing....
Waverly Golden

Arctic Monkeys coming to Salt Lake City in 2023

The Arctic Monkeys, the English rock band, announced their 2023 tour dates and Salt Lake City made the list. 
19 hours ago
Salt Lake County DA Sim Gill...
Simone Seikaly

Salt Lake County DA will not file charges in officer-involved incident

Salt Lake County DA Sim Gill says an incident on March 17, 2022, doesn't fall into the category of an officer-involved critical incident.
19 hours ago
University of utah sign pictured, an assault off campus at a frat house is being investigated...
Becky Bruce

SLCPD investigating reported sexual assault at frat house near University of Utah

An alert went out to University of Utah faculty, staff and students saying the sexual assault happened at the Pi Kappa Alpha frat house.
19 hours ago

Sponsored Articles

Young woman receiving laser treatment...
Form Derm Spa

How facial plastic surgery and skincare are joining forces

Facial plastic surgery is not only about looking good but about feeling good too. The medical team at Form Spa are trained to help you reach your aesthetic outcomes through surgery and through skincare and dermatology, too.
large group of friends tohether in a park having fun...
BYU MBA at the Marriott School of Business

What differentiates BYU’s MBA program from other MBA programs

Commitment to service is at the heart of BYU’s MBA program, which makes it stand out among other MBA programs across the country.
a worker with a drill in an orange helmet installs a door in the house...
Price's Guaranteed Doors

Home improvement tip: Increase the value of your home by weatherproofing doors

Make sure your home is comfortable before the winter! Seasonal maintenance keeps your home up to date. Read our tips on weatherproofing doors.
Curb Appeal...
Price's Guaranteed Doors

How to have the best of both worlds for your house | Home security and curb appeal

Protect your home and improve its curb appeal with the latest security solutions like beautiful garage doors and increased security systems.
A paper reading IRS, internal revenue service is pictured...
Jordan Wilcox

The best strategies for dealing with IRS tax harassment | You have options!

Learn how to deal with IRS tax harassment. This guide will teach you how to stop IRS phone calls and letters, and how to handle an IRS audit.
spend a day at Bear Lake...
Bear Lake Convention and Visitors Bureau

You’ll love spending the day at Bear Lake | How to spend a day at Bear Lake

Bear Lake is a place that needs to be experienced. Spend a day at Bear Lake.
Curiosity rover finds evidence of Mars’ ancient salty lakes