“Cookie,” “brain” and “deformed waffle” are the words used to describe a mysterious formation on the surface of Mars that appeared in a photograph released last week by NASA. The strange landform is circular with raised ridges running through its center. Scientists said it measures roughly 2 kilometers (1.2 miles) wide.

Rather than being the product of some giant Martian bakery, the cookie-like formation was likely the result of ancient volcanic activity, according to researchers with NASA’s Jet Propulsion Laboratory in California. The feature was discovered in the planet’s Athabasca region, the site of some of Mar’s youngest lava flows.

The Martian surface, once a violent environment, is replete with dormant volcanoes. Some of them are 100 times larger than any volcano on Earth, in part because Mars’ crust, unlike Earth’s, remains stationary, allowing the lava to pile higher for much longer. Lower surface gravity on Mars has resulted in much longer lava flows than those produced by Earth’s volcanic eruptions, NASA said.

The image of the Martian cookie was captured by NASA’s Mars Reconnaissance Orbiter, which was launched in 2005 to look for signs of water on the Red Planet. The orbiter took seven months to reach Mars and has studied objects on its surface “as small as a dinner table,” according to the laboratory. Its HiRISE camera is one of six cutting-edge instruments aboard the orbiter.

Bizarre formations on the Martian surface have caught astronomers’ attention before. The earliest was in 1976 when NASA photographed what appeared to be a human face on the planet’s surface. The image was taken during NASA’s Viking missions to Mars and led to several popular conspiracies about the presence of intelligent life.

Martian_face_viking A small part of the Cydonia region is shown, taken by the Viking 1 orbiter and released by NASA July 25, 1976. The image shows what appeared to be a face on the Martian surface. Photo: Creative Commons

More recently, in January 2013, NASA found what looked like a giant iguana among the Martian landscape. Other strange sightings have included a rat, a skull and even a door handle.