IE 11 is not supported. For an optimal experience visit our site on another browser.

'Life on Mars' explained

Now there's a "Mermaid on Mars" to go along with the time-honored Face on Mars: Some Red Planet fans see the sculpture of a seated woman in one of the panoramas sent back to Earth by NASA's Spirit rover.

Is this suppressed evidence of alien artistry? Does the picture actually show a creature of some sort? Based on analysis of the stereo imagery, the best explanation is that the feature was indeed sculpted - not by a Martian hand, but by the Martian wind.

Some folks make a habit of looking for strange features in the pictures that have come from the Mars rovers over the past four years - features like "bunny ears" (bits of fabric left behind by the rovers), or the "Martian footprint" (the imprint of a wheel tread), or "rover rotini" (a mysterious curlicue that might be a mark left behind by a drill).

The Martian Mermaid has taken its place as one of those enigmas, elevated to prominence by a Daily Mail article headlined "Life on Mars?" The Telegraph wondered whether the sculpture was the Martian equivalent of Denmark's Little Mermaid. Even the TODAY show's blog joined in the fun.

Some people take this seriously, however - hinting darkly that NASA is covering up evidence of alien life. So it's a good idea to try to figure out just what the feature is. As usual, Emily Lakdawalla does a great job of collecting the evidence on the Planetary Society blog.

The key step is to go back to the original images that were collected by Spirit last November. If you take out your red-blue 3-D glasses (you do keep a pair with you at all times, right?), a look at the high-resolution stereo imagery will be instructive: The "sculpture" appears to have some depth to it, and the more you look, the more it appears to be a spiky spire of rock stretching out from wind-eroded formations.

Cornell astronomer Jim Bell, who heads the scientific team behind the Mars rovers' panoramic cameras, confirmed my impression when I contacted him today. By now he's quite familiar with the image and the controversy, in large part because he's been getting dozens of phone calls from reporters asking about the Mermaid (or is that Bigfoot?).

"It's a funky little bizarre wind-carved rock formation," Bell told me. "It's not unusual at all."

Bell figures that the feature is about 2 inches (5 centimeters) high. He said his team has come across a variety of curious-looking shapes like this one as they've sorted through the more than 200,000 images returned by the Mars rovers over the past four years. To date, none has provided clues worth following in the search for traces of ancient life on Mars, he said.

"Believe me, I would be leading the parade if there were really pictures of little men or fossils," Bell told me.

Although he's a little nonplussed about the conspiracy angle, Bell said he welcomes any opportunity to draw attention to the fantastic pictures sent back by Spirit and Opportunity - pictures that can be seen at NASA's Web site at Cornell's Pancam Web site. Bell also highlights the best images in his recently published coffee-table book, "Postcards From Mars." We also have a nice selection of images in our space gallery, including this rover retrospective.

"I think it's great that people are interested in the rovers and that they're still generating news - even if it's bizarre," Bell said.

Case closed? You decide - then add your comments below.