During the 55th Lunar and Planetary Science Conference held in the United States, scientists from the SETI Institute and the Mars Institute announced a sensational discovery. They found the remains of a giant volcano with a diameter of 450 km on Mars.

Studying Noctis Labyrinthus, also known as the Labyrinth of the Night, the largest labyrinth (complex of intricate canyons) on Mars, as well as the monumental canyons of the Mariner Valley, they discovered that these are actually the remains of a giant ancient volcano destroyed by erosion beyond recognition. The structure was tentatively named Noctis volcano (Volcano of the Night).

The volcano’s enormous size, 9,022 meters high and 450 km in diameter, and complex history of landscape modifications indicate that it has been active for a very long time. In its southeastern part, there is a thin layer of relatively recent volcanic sediments, under which there is probably a large layer of ice. This is a very interesting place to study during the next scientific missions to Mars with the help of robots and, in the future, humans. In addition, large ice deposits are a good place to establish a base on Mars.

“We were examining the geology of an area where we had found the remains of a glacier last year when we realized we were inside a huge and deeply eroded volcano,” said Dr. Pascal Lee, planetary scientist with the SETI Institute and the Mars Institute, the lead author of the study.

Volcano Noctis does not have the conventional cone characteristic of typical volcanoes, as cracks and erosion have changed its appearance over the many years since the last eruption. However, on closer inspection, one can recognize the key features that indicate a volcano. Inside the “inner zone” that defines the remains of the volcano, an arc of high plateaus marks the central peak with a climax of 9,022 meters. The surviving parts of the volcano’s slopes extend in different directions to the edge of the “outer zone,” 225 km from the summit. The remains of the caldera, a destroyed volcanic crater that once contained a lava lake, can be seen in the center of the structure. Lava flows, pyroclastic deposits (formed by volcanic solid materials such as ash, cinder, pumice, and tephra), and hydrothermal mineral deposits occur in several areas within the perimeter of the volcanic structure.

But much about the giant volcano remains a mystery. While it is clear that it has been active for a long time and began to form early in Mars’ history, it is not known how. Likewise, although it has experienced many eruptions, even in modern times, it is not known whether it is volcanically active now and whether it could erupt again. And, if it has been active for a very long time, could this combination of prolonged heat and water from the ice have allowed life to be sustained in this place?

“It’s really a combination of things that makes the Noctis volcano site exceptionally exciting. It’s an ancient and long-lived volcano so deeply eroded that you could hike, drive, or fly through it to examine, sample, and date different parts of its interior to study Mars’ evolution through time. It has also had a long history of heat interacting with water and ice, which makes it a prime location for astrobiology and our search for signs of life. Finally, with glacier ice likely still preserved near the surface in a relatively warm equatorial region on Mars, the place is looking very attractive for robotic and human exploration,” says Pascal Lee.

Scientists have already chosen a possible landing site for the future research mission in the vicinity of the Noctis volcano. The word is now up to NASA.