JPL
Careers
Education
Science & Technology
JPL Logo
JPL Logo
Mars
.

NASA’s MRO Finds Water Flowed on Mars Longer Than Previously Thought

Jan. 26, 2022
NASA's Mars Reconnaissance Orbiter used its Context Camera to capture this image of Bosporos Planum, a location on Mars. The white specks are salt deposits found within a dry channel.
NASA's Mars Reconnaissance Orbiter used its Context Camera to capture this image of Bosporos Planum, a location on Mars. The white specks are salt deposits found within a dry channel.
Credit: NASA/JPL-Caltech/MSSS
Full Image Details

Caltech researchers used the Mars Reconnaissance Orbiter to determine that surface water left salt minerals behind as recently as 2 billion years ago.

Mars once rippled with rivers and ponds billions of years ago, providing a potential habitat for microbial life. As the planet’s atmosphere thinned over time, that water evaporated, leaving the frozen desert world that NASA’s Mars Reconnaissance Orbiter (MRO) studies today.

It’s commonly believed that Mars’ water evaporated about 3 billion years ago. But two scientists studying data that MRO has accumulated at Mars over the last 15 years have found evidence that reduces that timeline significantly: Their research reveals signs of liquid water on the Red Planet as recently as 2 billion to 2.5 billion years ago, meaning water flowed there about a billion years longer than previous estimates.

The findings – published in AGU Advances on Dec. 27, 2021 – center on the chloride salt deposits left behind as icy meltwater flowing across the landscape evaporated.

Get the Latest JPL News

SUBSCRIBE TO THE NEWSLETTER

While the shape of certain valley networks hinted that water may have flowed on Mars that recently, the salt deposits provide the first mineral evidence confirming the presence of liquid water. The discovery raises new questions about how long microbial life could have survived on Mars, if it ever formed at all. On Earth, at least, where there is water, there is life.

The study’s lead author, Ellen Leask, performed much of the research as part of her doctoral work at Caltech in Pasadena. She and Caltech professor Bethany Ehlmann used data from the MRO instrument called the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to map the chloride salts across the clay-rich highlands of Mars’ southern hemisphere – terrain pockmarked by impact craters. These craters were one key to dating the salts: The fewer craters a terrain has, the younger it is. By counting the number of craters on an area of the surface, scientists can estimate its age.

Click on this interactive visualization of the Mars Reconnaissance Orbiter and take it for a spin. The “HD” button in the lower right offers more detailed textures. The full interactive experience is at Eyes on the Solar System. Credit: NASA/JPL-Caltech

MRO has two cameras that are perfect for this purpose. The Context Camera, with its black-and-white wide-angle lens, helps scientists map the extent of the chlorides. To zoom in, scientists turn to the High-Resolution Imaging Science Experiment (HiRISE) color camera, allowing them to see details as small as a Mars rover from space.

Using both cameras to create digital elevation maps, Leask and Ehlmann found that many of the salts were in depressions – once home to shallow ponds – on gently sloping volcanic plains. The scientists also found winding, dry channels nearby – former streams that once fed surface runoff (from the occasional melting of ice or permafrost) into these ponds. Crater counting and evidence of salts on top of volcanic terrain allowed them to date the deposits.

A Mineral Mystery for Teachers
A Mineral Mystery Project for Students

“What is amazing is that after more than a decade of providing high-resolution image, stereo, and infrared data, MRO has driven new discoveries about the nature and timing of these river-connected ancient salt ponds,” said Ehlmann, CRISM’s deputy principal investigator. Her co-author, Leask, is now a post-doctoral researcher at Johns Hopkins University’s Applied Physics Laboratory, which leads CRISM.

The salt minerals were first discovered 14 years ago by NASA’s Mars Odyssey orbiter, which launched in 2001. MRO, which has higher-resolution instruments than Odyssey, launched in 2005 and has been studying the salts, among many other features of Mars, ever since. Both are managed by NASA’s Jet Propulsion Laboratory in Southern California.

“Part of the value of MRO is that our view of the planet keeps getting more detailed over time,” said Leslie Tamppari, the mission’s deputy project scientist at JPL. “The more of the planet we map with our instruments, the better we can understand its history.”

More About the Mission

JPL, a division of Caltech in Pasadena, California, manages the MRO mission for NASA’s Science Mission Directorate in Washington. The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. MARCI and the Context Camera were both built and are operated by Malin Space Science Systems in San Diego.

For more information about MRO:

https://mars.nasa.gov/mro/

and

www.nasa.gov/mission_pages/MRO/main/index.html

News Media Contact

Andrew Good

Jet Propulsion Laboratory, Pasadena, Calif.

818-393-2433

andrew.c.good@jpl.nasa.gov

Karen Fox / Alana Johnson

NASA Headquarters, Washington

301-286-6284 / 202-358-1501

karen.c.fox@nasa.gov / alana.r.johnson@nasa.gov

2022-007

Related News

Solar System .

NASA’s Magellan Data Reveals Volcanic Activity on Venus

Mars .

Engineers Keep an Eye on Fuel Supply of NASA’s Oldest Mars Orbiter

Solar System .

Study Finds Ocean Currents May Affect Rotation of Europa’s Icy Crust

Mars .

NASA’s Curiosity Views First ‘Sun Rays’ on Mars

Solar System .

Study Finds Venus’ ‘Squishy’ Outer Shell May Be Resurfacing the Planet

Mars .

NASA’s Perseverance Rover Set to Begin Third Year at Jezero Crater

Mars .

NASA’s Perseverance Rover Shows Off Collection of Mars Samples

Solar System .

NASA’s NuSTAR Telescope Reveals Hidden Light Shows on the Sun

Mars .

NASA’s Curiosity Finds Surprise Clues to Mars’ Watery Past

Mars .

NASA’s Perseverance Rover Completes Mars Sample Depot

Explore More

Image .

Ingenuity and Perseverance Make Tracks

Image .

Eumenides Dorsum

Image .

Chaos

Image .

Perseverance Views Drifting Clouds

Image .

Icaria Fossae

Image .

South Polar Ice

Image .

South Polar Ice

Video .

Perseverance's Mastcam-Z Views Ingenuity's 47th Takeoff

Image .

Southern Dunes

Image .

South Polar Ice

About JPL
Who We Are
Executive Council
Directors
Careers
Internships
The JPL Story
JPL Achievements
Documentary Series
Annual Reports
Missions
Current
Past
Future
All
News
All
Earth
Solar System
Stars and Galaxies
Subscribe to JPL News
Galleries
Images
Videos
Audio
Podcasts
Apps
Visions of the Future
Slice of History
Robotics at JPL
Events
Lecture Series
Team Competitions
Speakers Bureau
Calendar
Visit
Public Tours
Virtual Tour
Directions and Maps
Topics
JPL Life
Solar System
Mars
Earth
Climate Change
Exoplanets
Stars and Galaxies
Robotics
More
Asteroid Watch
NASA's Eyes Visualizations
Universe - Internal Newsletter
Social Media
Get the Latest from JPL
Follow Us

JPL is a federally funded research and development center managed for NASA by Caltech.

More from JPL
Careers Education Science & Technology Acquisitions JPL Store
Careers
Education
Science & Technology
Acquisitions
JPL Store
Related NASA Sites
Basics of Spaceflight
Climate Kids
Earth / Global Climate Change
Exoplanet Exploration
Mars Exploration
Solar System Exploration
Space Place
NASA's Eyes Visualization Project
Voyager Interstellar Mission
NASA
Caltech
Privacy
Image Policy
FAQ
Feedback
Site Managers: Veronica McGregor, Randal Jackson
Site Editors: Tony Greicius, Naomi Hartono
CL#: 21-0018