When last we heard from Mars Curiosity, the plucky little rover had detected traces of possible biogenic methane gas. Now, an image taken last month has been heavily analyzed, and it shows features some scientists say are consistent with fossil stromatolites beds on Earth:

Identifying signs of life, or at least life-supporting conditions, on Mars has always been one of Curiosity’s main missions, since it first set down in the Gale Crater back in 2012. Since then, the rover has taken countless samples and photographs of Martian terrain, even as it made its way to Mount Sharp – where the latest phase of experiments and drilling have begun.

Some early looks at these photographs revealed mysteriously pitted and rippled surfaces on the Red Planet – geological patterns that looks suspiciously just like those seen in prehistoric stone samples found back on Earth. his patterning, it has been suggested, could have been caused by the ebb and flow of warm oceans on mats of primitive microbial life.

More on the image here and here. Below are a couple of fossil stromatolites from Earth and one close up of the Martian landscape in question. These terrestrial structures are well studied, their features well known. There’s been plenty of hype, inconsistent findings, controversial findings, and flat out hoaxing on claims of Martian life, so skepticism should be the default position here.

But, you can see the distinctive swirling, layered patterns of these two terrestrial version are likely well within Curiosity’s camera resolution even from several meters away. The rover is also equipped with an abrasive tool and chemical sensors to help it get passed any outer, mineral patina deposited by eons of weathering. So, hopefully, we can get a better idea if this is worth looking into deeply without disrupting the current mission schedule too much.

Stromatolites in the Hoyt Limestone (Cambrian) exposed at Lester Park, near Saratoga Springs, New York.

Stromatolites in the Soeginina Beds (Paadla Formation, Ludlow, Silurian) near Kübassaare, Saaremaa, Estonia.

And here is one of the best images of the Martian item causing all the fuss …