Don’t peek at the answer until you’ve given this a good try! Then, scroll down a bit and the truth will be revealed to you.

(Image Credit: NASA)

What is "world" is it? A nerve center? Veins on an elephant? A bad case of "red-eye?"

No, it’s an intricate network of streams, rivers and lakes which may have carried water across Mars! The image was taken with new three-dimensional images from the Mars Global Surveyor spacecraft and a powerful state-of-the-art computer code that "models" overland water flow.

Scientists have long been puzzled as to why some ancient river-like features on the red planet do not seem to connect to one another and often lack smaller stream features. "If you look at a photograph of the surface of Mars, the river features begin and end abruptly, and often lack small-scale features," said Marc G. Kramer, a visiting National Research Council scientist at NASA Ames Research Center in California’s Silicon Valley. Many scientists have argued that these features were formed from localized groundwater seeping to the surface. Others countered that they formed from rains during a time when Mars may have had a thicker atmosphere.

"What we found in this study," Kramer said, "is that many of these apparently fragmented river features may have connected or flowed into depressions that resemble ancient lake beds. Some of the larger depressions are comparable in size to the Great Lakes in North America in terms of surface area."

The study of surface depressions in conjunction with river features, provides a more complete picture of a surface water network that may have existed on what must have been a warmer early Mars. "The data coming out of the Mars Global Surveyor and Mars Odyssey Mission are quite revealing," Kramer said. "We were able to study the planet in ways that were previously not possible."