Others looking at the same pictures defer to "bizarre geology", not biology as cause for the Mars spots.

Many point to the comings and goings of frost, exposing or covering up the landscape. The features, they say, are a product of a cyclic blend of season, local temperature, properties of the surface, and a complex process of carbon dioxide and water vaporizing and solidifying in the harsh Martian environment.

As a response to doubters, Szathmary told SPACE.com that the dark dune spots do not usually appear on the ridges exposed to the maximum sunlight, but in the deeper, more protected areas.

"This is evidence against a simple frosting-defrosting mechanism," Szathmary said.

The biological interpretation of what the splotches represent may, indeed, be clinging to life.

Horvath and his colleagues argue that the life cycle of photoautotrophic Martian surface organisms could be root cause for the dark markings. This Martian life exhibits evolved pigments with high absorbency, they suggest.

Due to the transparency of the ice, light bathes the organisms. In turn, the organisms absorb the emerging sunlight and thus warm up at the end of the winter. From a frozen state, they pass to a highly heated stage, which also applies to part of the ice around them. Now the organisms find themselves in a liquid solute. In contact with the underlying surface, the Mars biota feeds off nutrients in the soil.

The fact that the spots mainly appear in the polar region suggests that a long period of sunlight is necessary for the features to form. On Earth, the closest known analog to such biology is a mid-ice photosynthethic bacterial grouping uncovered in Antarctica, the research team reports.

Horvath and his associates have urged NASA to plop down a Mars rover in the southern polar region. Between the end of January and April 2004, the seasonal change from winter to spring will see the onset of dark dune spots. Having a robot rumble over to near the edge of a promising spot would test this "fascinating possibility of life on the planet," the scientists conclude.

Mars has become a huge spectator sport.

A network of onlookers scope out thousands of outtakes from the Mars Orbiter Camera (MOC) carried by the Mars Global Surveyor. Independent research groups and chat rooms are abuzz with discussion about what this or that picture indicates.

One of the more intriguing websites, Marsunearthed, is painstakingly packed with comparative imagery.

"When we were putting together the website, we decided early on to let the images, comparisons, and animations speak for themselves, with little to no editorial commentary," said James Fitzhugh. Along with Jeff Williams, the two website developers point to drastic and surreal changes that sweep across Mars, captured in MGS camera clicks over the years.

"Scientists and academicians are all too often unwilling to go with what the data suggests if that data is contrary to prior theorem. We are not bound by the same obligations as they are to overly conservative institutions. It is our hope that by assembling and organizing enough data that it will allow them to move two steps out of the box that many seem to be trapped in," Fitzhugh said.

Jeff Williams said that the sheer number of private individuals looking at the images helps insure each available photo is scrutinized in detail, and by people from various disciplines.

The south polar region appears to have the look of growth and vegetation, Williams said. "We've seen patterns and forms that seem to suggest biological activity. Of course, this is pure speculation at this point. But we know that life finds a way, even in the harshest environments on our own planet, so that the possibility of finding Martian life, even in the polar regions, can't be completely discounted," he said.

Added to such speculation, there is also room for super speculation.

For one passionate MGS analyst -- a camouflage and visual expert with over 30 years of military experience -- Clarke's Banyan trees are, in reality, wiring bundles on the underside of a circuit board. He smells a NASA cover-up that needs uncovering.