Scientists may have pinpointed a massive, oddly shaped volcano taller than Mount Everest on the surface of Mars 鈥� and it has been hiding in plain sight for decades, according to new research.
The possible identification of a previously unknown Martian volcano has made waves across the planetary sciences community since Mars Institute Chairman Dr. Pascal Lee, lead author of an abstract about the formation, presented the findings on March 13 at the 55th Lunar and Planetary Science Conference in The Woodlands, Texas.
The research has drummed up excitement 鈥� and attracted some skeptics.
Lee said he and Sourabh Shubham, a doctoral student of geology at the University of Maryland, College Park, have identified a volcano within Mars鈥� Noctis Labyrinthus region 鈥� a gnarled patch of terrain near the equator with a web of canyons. The volcano in the 鈥淟abyrinth of Night鈥� may have eluded scientists despite years of satellite observation because it does not tower over its surrounding landscape, Lee said.
"It鈥檚 also deeply eroded, eaten up and collapsed by erosion to the point that unless you鈥檙e really looking for a volcano, you would be really hard-pressed to spot it very quickly," he told CNN.
If the team is correct, the revelation could have broad implications for scientists鈥� understanding of Martian geology. And, Lee said, he hopes the discovery could help lure future exploratory missions to the area to search for water ice or even signs of life.
The smoking gun
Initially, the research team鈥檚 efforts led to a study presented in March 2023 that suggested the Noctis Labyrinthus region may be home to a massive glacier covered in salt deposits.
Since then, Lee and Shubham have pored through data collected by NASA鈥檚 Mars Reconnaissance Orbiter, trying to determine whether water might still be frozen beneath the salt.
The hunt for water ice is key 鈥� it鈥檚 a resource that could be used to sustain human exploration on Mars or even converted into rocket fuel. While scouring the landscape, however, Lee said he was struck by 鈥渢his little lava flow next to the glacier.鈥�
The lava hadn鈥檛 yet been fully oxidized, a process that would turn it the same muddy orange hue as the surrounding surface, Lee said.
That indicated the lava might be relatively fresh 鈥� the first hint that an undetected volcano might be lurking nearby.
鈥淲e started looking at the landscape carefully,鈥� Lee said. 鈥淎nd sure enough, when we examined the high points of this region, we noticed that they formed an arc.鈥�
That arc is reminiscent of a shield volcano, Lee added, a type of volcano that also exists on Earth. Shield volcanoes are characterized by their broad, gently sloping sides 鈥� appearing wider than they are tall.
That finding led Lee and Shubham to gather more evidence, eventually determining that a 29,600-foot (9,022-metre) peak was actually the tip of a Martian volcano.
That鈥檚 a few hundred feet taller than Mount Everest, which rises 29,029 feet (8,848 metres) above sea level.
Mapping Mars
Scientists have already cataloged and named more than a dozen volcanoes on Mars, including Olympus Mons, the tallest known volcano in our solar system.
Lee said he and Shubham are working to spell out the findings in a peer-reviewed paper, a more detailed work that could lend more credence to the idea across the scientific community.
But the hypothesis of the volcano鈥檚 existence is already attracting attention.
鈥淚t鈥檚 a big thing,鈥� said Dr. Adrien Broquet, a Humboldt Research Fellow at the German Aerospace Center who has studied Martian volcanoes. 鈥淚t鈥檚 as tall as the tallest mountain we have on the Earth. So, it鈥檚 not a small feature on Mars for which we鈥檝e had a question mark. And we have plenty of question marks (about the surface of Mars.)鈥�
A search for life in the Labyrinth of Night
The journey to identifying this volcano 鈥� which the team has provisionally named 鈥淣octis volcano鈥� 鈥� began in 2015, Lee said, when NASA asked the planetary science community to propose intriguing locations on Mars where the US space agency might land future human exploration missions.
Lee proposed a site just east of Noctis Labyrinthus, which was dubbed 鈥淣octis landing.鈥�
The location could be an ideal place to search for alien life on Mars, said Lee, who is also a planetary scientist at the SETI Institute, a nonprofit dedicated to searching for evidence of extraterrestrial life.
鈥淥f course, we鈥檙e not looking for a little green man with antennae,鈥� Lee said. 鈥淏ut we鈥檙e looking for microbes that would not fit into the tree of life on Earth.鈥�
Noctis Labyrinthus could be ideally situated for this hunt, according to Lee.
鈥淚f you want to look for ancient life, you drive east (from Noctis Labyrinthus) into the canyons,鈥� Lee said, referring to Valles Marineris, the largest canyon in our solar system.
There, explorers could 鈥渟ift through the rock layers鈥� to scour for fossils, he said.
Or, Lee suggested, a mission could venture west to a volcanic region called the Tharsis plateau, where warm caves may harbor living microbes.
With such tantalizing potential, Lee has committed to studying Noctis Labyrinthus to build a case for sending exploratory missions there.
A volcano, a glacier and the history of Mars
The existence of a volcano in Noctis Labyrinthus could also help explain the creation of this bizarre landscape.
Scientists suspect magma bubbling up from Mars鈥� interior formed the labyrinthian valleys, but the details are up for debate.
One theory is that when the magma pushed up on the Martian crust, it cracked and splintered, leaving behind a maze of branching canyons.
Lee favours an alternative theory: This model suggests that the Martian crust in Noctis Labyrinthus is full of ice. And when magma seeped in, it melted or vaporized ice and rock beneath the surface, causing swaths of the terrain to cave in.
The existence of a volcano in the region, Lee said, might offer more support for the latter theory.
The science of certainty
Three scientists who were not involved in the research told CNN that they would not be surprised if a volcano were hidden near Noctis Labyrinthus.
Volcanoes of all shapes and sizes riddle the surface of the broader region, including the Tharsis plateau to the west of Noctis Labyrinthus.
However, Dr. Ernst Hauber, a staff scientist at the German Aerospace Center鈥檚 Institute of Planetary Research, is one geologist in the community who would like to see a peer-reviewed paper before he accepts Lee and Shubham鈥檚 version of events.
鈥淭hey are very vague about chronology, about the timing of events,鈥� Hauber told CNN, referring to the brief abstract Lee and Shubham published.
Among Hauber鈥檚 questions: If the volcano could still be active, as Lee suggests, why hasn鈥檛 it poured lava into the surrounding canyons? Why aren鈥檛 there more visible signs of lava near the peak? Could this actually be an impact crater Lee is looking at?
鈥淚鈥檓 a bit skeptical for several reasons,鈥� Hauber said.
Broquet of the German Aerospace Center and Dr. David Horvath 鈥� a research scientist at the nonprofit Planetary Science Institute in Tucson, Arizona 鈥� both said in separate interviews they would like to see additional data supporting the ideas Lee and Shubham presented.
But Broquet and Horvath said they find the abstract intriguing.
鈥淭his does look like a really good candidate (for a volcano),鈥� Horvath said.
Lee said he is welcoming input from other scientists, anxious for additional evidence to support his research. But he also expresses confidence.
鈥淚n this case, my sense is that there鈥檚 really no room for plausible alternate hypotheses,鈥� Lee said, adding that he鈥檚 85% to 90% certain he has located a new Martian volcano.
鈥淏ut extraordinary claims require extraordinary evidence,鈥� Lee added, quoting the late astronomer Carl Sagan, for whom he once worked as a teaching assistant.
