This Gross-Looking Mars Photo Isn't What It Seems

So…kind of gross, right? It’s hard to tell from a glance where this was found, but under a rock, in a swamp or somewhere inside an animal’s intestinal tract come to mind.

The fact is, however, the strangely organic-looking something was found tens of millions of miles from Earth and there’s nothing biological about it at all. It is, instead, a one-kilometer (.62 mi.) stretch of Mars’s seasonal ice cap, in a picture taken by the Mars Reconnaissance Orbiter in February, 2009, and newly released by NASA’s and Caltech’s Jet Propulsion Laboratory.

Much of the ice in the Martian poles is made of carbon dioxide, and as springtime approaches and the planet warms slightly, the ice sublimes—or goes directly from a solid state to a gas. The fine wrinkles in the formation are troughs under the ice through which the gas flows, ultimately escaping through the larger-crater like formations where the ice has collapsed or sublimed away completely. The dark color is the result of dust that is carried up by the gas and then falls back on the surface.

The universe of living things may be very different from that of non-living ones. But that doesn’t mean its always easy to tell one from the other.

Write to Jeffrey Kluger at jeffrey.kluger@time.com.