National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
News & Events
Evidence of Icy Region and Recent Climate Change Observed on Mars
Evidence of Icy Region and Recent Climate Change Observed on Mars
26 Jul 2001
(Source: Brown University)

News Service
Brown University

News Service Contact:
Janet Kerlin,

PROVIDENCE, R.I. - New images of the surface of Mars provide the first direct evidence that the climate of Mars changed during the last 100,000 years, much more recently than the hundreds of millions of years scientists had previously thought, according to Brown University geologist John Mustard. The high- resolution images show evidence of water ice closer to the equator than had previously been observed.

Mustard, with graduate student Christopher Cooper and undergraduate Moses Rifkin, wrote about the findings in the July 26 issue of Nature.

The images were recorded by the Mars Orbiter Camera aboard NASA's unmanned Mars Global Surveyor. They show a unique surface terrain of pits and hummocks that appears to have been soil once impregnated by water ice. The ice has since evaporated, leaving a five-meter thick mantle of porous terrain that is being broken up by wind and other factors.

"Where the mantle is still intact, you could conceive of water ice not far below the surface," Mustard said. "Where it's broken into pits and hummocks, the water is gone."

The geologically young terrain was observed in two bands north and south of the equator at 30 to 60 degrees latitude. The location is significant because it shows that ice in the soil was once present as close to the equator as 30 degrees and as recently as 100,000 years, while previous observations had shown that ice had been present in the polar regions. Due to climate change, it now appears the icy region moved from the planet's poles to nearer its equator, and has now retreated to the poles, the most recent of probably many such cycles, Mustard said.

"While we have always thought the climate of Mars has changed over time, this is direct evidence for change. And that change fits with the theory of periodic climate change, similar to the change that causes the ice ages on Earth," Mustard said.

"Maybe we don't have to go to the poles to find water ice. It's easier for a spacecraft to survive at the equator," Mustard said.

The work was supported by grants from NASA.

[ (128KB)]
A high-resolution image of Mars' surface, left, shows an ice-rich layer that appears to be flowing downhill. The newly observed terrain is a mixture of water ice and dust and was formed in the past 100,000 years, much more recently than previously thought.

News Archive Search  Go!
Show  results per page
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 26 Jul 2001