A picture of the layered outcrops of the West Candor Chasma taken by the Mars Global Surveyor MOC (Mars Orbiter Camera). The image has been colorized for better viewing. Click on image for full size (72K JPEG) NASA/JPL/Malin Space Science Systems

High-resolution pictures taken by the MOC (Mars Orbiter Camera) aboard the MGS show layers of sedimentary rocks that could be evidence of past lakes and seas on Mars. As on Earth, sedimentary rocks hold the history of the planet.

"We see distinct, thick layers of rock within craters and other depressions for which a number of lines of evidence indicate that they may have formed in lakes or shallow seas. We have never before had this type of irrefutable evidence that sedimentary rocks are widespread on Mars," said Dr. Michael Malin, principal investigator for the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft. "These images tell us that early Mars was very dynamic and may have been a lot more like Earth than many of us had been thinking." Malin added, "I have not previously been a vocal advocate of the theory that Mars was wet and warm in its early history. But my earlier view of Mars was really shaken when I saw our first high- resolution pictures of Candor Chasma. The nearly identically thick layers would be almost impossible to create without water."

But, these observations are only one piece in a very complex puzzle. Some scientists think that the layers within these sedimentary rock formations are so prominent because Mars was actually a lot colder and drier 3.5 billion years ago, allowing for more dust to be airborne and thicker layers to be formed.

It may seem confusing that some scientists take these observations as confirmation of a wetter, warmer Mars, while others think exactly the opposite thinking of a colder, drier Mars. This is the wonder of the field of science. Only with further investigation, discussion, and missions to the Martian surface will we know for sure what these awesome surface features tell us about the history of the Red Planet.

"Mars seems to continually amaze us with unexpected discoveries," said Dr. Edward Weiler, Associate Administrator for Space Science at NASA Headquarters. "This finding just might be the key to solving some of the biggest mysteries on Mars, and it also tells us that our new Mars exploration program needs the flexibility to follow up in a carefully thought-out manner."

A picture of the layered outcrops of the West Candor Chasma taken by the Mars Global Surveyor MOC (Mars Orbiter Camera). The image has been colorized for better viewing. Click on image for full size (72K JPEG) NASA/JPL/Malin Space Science Systems

Pictures taken by the camera aboard the MGS show layers of sedimentary rocks that could be evidence of past lakes and seas on Mars. As on Earth, sedimentary rocks hold the history of the planet.

Right now, we think of Mars as just a bunch of dry rocks. But, "these images tell us that early Mars was very dynamic and may have been a lot more like Earth than many of us had been thinking," says Malin. Malin is one of the principal investigators of the MGS program. He added, "I have not previously been a vocal advocate of the theory that Mars was wet and warm in its early history. But my earlier view of Mars was really shaken when I saw our first high- resolution pictures of Candor Chasma. The nearly identically thick layers would be almost impossible to create without water."

But, these observations are only one piece in a very big puzzle. Some scientists think that the layers within these sedimentary rock formations are so prominent because Mars was actually a lot colder and drier 3.5 billion years ago, allowing for more dust to be airborne and thicker layers to be formed.

It may seem confusing that some scientists take these observations as confirmation of a wetter, warmer Mars, while others think exactly the opposite thinking of a colder, drier Mars. This is the wonder of the field of science. Only with further investigation, discussion, and missions to the Martian surface will we know for sure what these awesome surface features tell us about the history of the Red Planet.

A picture of the layered outcrops of the West Candor Chasma taken by the Mars Global Surveyor MOC (Mars Orbiter Camera). The image has been colorized for better viewing. Click on image for full size (72K JPEG) NASA/JPL/Malin Space Science Systems

Pictures like the one to the left tell scientists that there may have been lakes and seas on Mars a long, long time ago. Right now, we think of Mars as a bunch of dry rocks. But the pictures that MGS took show that Mars may have been wetter and drier 3.5 billion years ago. That means that in the past, Mars may have been more like the Earth is now.

Use your imagination to picture Mars with lakes and seas on it!