- \n
- Scientists discovered a giant Martian volcano<\/strong> hiding in plain sight near the planet\u2019s equator.<\/li>\n
- The heavily eroded volcano<\/strong> provides insight into Mars\u2019 evolution over time.<\/li>\n
- Conditions for life may exist<\/strong> there, as possible glacial remains lie at the volcano\u2019s base, creating a potential destination for future scientific exploration.<\/li>\n<\/ul>\n
SETI published this original article on March 13, 2024. Edits by EarthSky.<\/em><\/p>\n
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Giant volcano on Mars hiding in plain sight<\/h3>\n
At the 55th Lunar and Planetary Science Conference held in The Woodlands, Texas, scientists revealed the discovery of a giant volcano and a possible sheet of buried glacial ice. The discovery is from the eastern part of Mars\u2019 Tharsis volcanic province, near the planet\u2019s equator. Mars-orbiting spacecraft have imaged this region repeatedly since Mariner 9 in 1971. But the region is deeply eroded beyond easy recognition, so the giant volcano had been hiding in plain sight for decades.<\/p>\n
The newly found volcano lies in one of Mars\u2019 most iconic regions. It\u2019s at the boundary between the heavily fractured maze-like Noctis Labyrinthus (Labyrinth of the Night) and the monumental canyons of Valles Marineris (Valleys of Mariner).<\/p>\n
Giant volcano on Mars named Noctis volcano<\/h3>\n
Temporarily designated Noctis volcano<\/em> pending an official name, the structure\u2019s center is at 7\u00b0 35\u2032 S, 93\u00b0 55\u2032 W. It reaches 9,022 meters (29,600 feet) in elevation and spans 450 kilometers (280 miles) in width. The volcano\u2019s gigantic size and complex modification history indicate it\u2019s been active for a very long time. Its southeastern sections have a thin, recent volcanic deposit beneath which glacial ice is likely still present. This combined giant volcano and possible glacial ice discovery is significant. It points to an exciting new location to study Mars\u2019 geologic evolution through time, search for life and explore with robots and humans in the future.<\/p>\n
![\"A](\"https:\/\/earthsky.org\/upl\/2024\/03\/NoctisVolcano-Mars-false-color-SETI.jpg\")
Topographic map showing the iconic location of the Noctis volcano between the largest volcanic and canyon provinces on Mars. Image via SETI\/ NASA\/ MGS\/ MOLA\/ Pascal Lee & Sourabh Shubham 2024.<\/figcaption><\/figure>\n Discovery of the giant volcano on Mars<\/h3>\n
Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute based at NASA Ames Research Center, was the lead author of the study. Lee said:<\/p>\n
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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.<\/p>\n<\/blockquote>\n
Several clues give away the volcanic nature of the jumbled, layered mesas and canyons in this part of Noctis Labyrinthus. The central summit area has several elevated mesas forming an arc. These areas reach a regional high and slope downhill away from the summit area. The gentle outer slopes extend out to 225 kilometers (140 miles) away in different directions. A caldera remnant \u2013 the remains of a collapsed volcanic crater \u2013 is near the center of the structure. Lava flows, pyroclastic deposits (made of volcanic particulate materials such as ash, cinders, pumice and tephra) and hydrated mineral deposits occur in several areas within the structure\u2019s perimeter.<\/p>\n
![\"Side](\"https:\/\/earthsky.org\/upl\/2024\/03\/NoctisVolcano-Mars-2-detailed-images-SETI-e1710423924264.jpg\")
Here\u2019s altimetry analysis from NASA\u2019s Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter, NASA\u2019s Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment and Context Imager, and ESA\u2019s Mars Express High Resolution Stereo Camera. The topographic map on the right shows the \u201crelict glacier\u201d discovered in 2023 and Noctis Landing, a candidate for future robotic and human exploration. Image via SETI\/ Left: Mars Express HRSC color mosaic \u00a9 ESA\/DLR\/FU Berlin CC BY-SA 3.0 IGO; Right same as Left; NASA MGS MOLA\/ Pascal Lee & Sourabh Shubham 2024.<\/figcaption><\/figure>\n A smoking gun<\/h3>\n
Sourabh Shubham, a graduate student at the University of Maryland\u2019s Department of Geology and the study\u2019s co-author, explained:<\/p>\n
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This area of Mars is known to have a wide variety of hydrated minerals spanning a long stretch of Martian history. A volcanic setting for these minerals had long been suspected. So, it may not be too surprising to find a volcano here. In some sense, this large volcano is a long-sought \u2018smoking gun\u2019.<\/p>\n<\/blockquote>\n
The study also reports the discovery of a large, 5,000-square-kilometer (1,930-sq-mi) area of volcanic deposits. The deposits within the volcano\u2019s perimeter consist of many low, rounded and elongated, blister-like mounds. Scientists interpret this \u201cblistered terrain\u201d as a field of \u201crootless cones,\u201d mounds produced by explosive steam venting or swelling. This venting happens when a thin blanket of hot volcanic materials comes to rest on top of a water or ice-rich surface.<\/p>\n
![\"False](\"https:\/\/earthsky.org\/upl\/2024\/03\/NoctisVolcano-topography-Mars-SETI.jpg\")
The Noctis volcano does not present the conventional cone shape of a typical volcano. Its long history of deep fracturing and erosion has modified it. However, upon close inspection, we can find several key features indicative of a volcano. Image via SETI\/ NASA\/ MRO\/ HiRISE\/ CTX\/ MGO\/ MOLA\/ Pascal Lee & Sourabh Shubham 2024.<\/figcaption><\/figure>\n Remains of a glacier<\/h3>\n
Just a year ago, Lee, Shubham and their colleague John W. Schutt had identified the spectacular remains of a glacier. They did so through a sizeable erosional opening in the same volcanic blanket. The researchers saw a light-toned deposit of sulfate salt with the morphologic traits of a glacier. They interpreted the sulfate deposit \u2013 made mainly of jarosite (a hydrous sulfate) \u2013 formed when the blanket of volcanic pyroclastic materials came to rest on a glacier and reacted chemically with the ice. Breached rootless cones identified in the current study show similar occurrences of polyhydrated sulfates. This further suggests the blistered volcanic blanket may be hiding a vast sheet of glacial ice underneath it.<\/p>\n
![\"View](\"https:\/\/earthsky.org\/upl\/2024\/03\/NoctisVolcano-glacier-and-sulfates-Mars-SETI.jpg\")
The southeastern part of the Noctis volcano has a well-preserved volcanic lava flow and pyroclastic deposit. These suggest the volcano remained active even in relatively recent times. The pyroclastic deposit presents \u201cblisters\u201d at its surface. These are \u201crootless cones,\u201d or steam vents produced when the hot pyroclastic materials came in contact with water ice. Breaches in the pyroclastic deposit reveal light-toned deposits of sulfate salts, expected products of chemical reactions between pyroclastic materials and water ice. Glacial ice might still be preserved, only protected under a thin layer of sulfate salts. Image via SETI\/ NASA\/ MRO\/ HiRISE\/ CTX\/ CRISM\/ Pascal Lee & Sourabh Shubham 2024.<\/figcaption><\/figure>\n The history of the volcano<\/h3>\n
The Noctis volcano presents a long and complex history of modification. That history may be from a combination of fracturing, thermal erosion and glacial erosion. Researchers believe the volcano is a vast shield of layered accumulations of pyroclastic materials, lavas and ice. The ice resulted from repeated buildups of snow and glaciers on its flanks through time. As fractures and faults eventually developed \u2013 in particular in connection with the uplift of the broader Tharsis region on which the volcano sits \u2013 lavas began to rise. The lava rose through different parts of the volcano, leading to thermal erosion and the removal of vast amounts of buried ice. Eventually, it led to the catastrophic collapse of entire sections of the volcano.<\/p>\n
Subsequent glaciations continued their erosion, giving many canyons within the structure their present distinctive shape. In this context, the \u201crelict glacier\u201d and the possible buried sheet of glacial ice around it might be remnants of the latest glaciation episode affecting the Noctis volcano.<\/p>\n
Mysteries remain<\/h3>\n
But much about the newly discovered giant volcano remains a mystery. Although it\u2019s clear it\u2019s been active for a long time and began to build up early in Mars\u2019 history, it\u2019s unknown how<\/em> early. Similarly, although it experienced eruptions in modern times, it\u2019s unknown if it\u2019s still volcanically active and might erupt again. And if it\u2019s been active for a long time, could the combination of sustained warmth and water from ice have allowed the site to harbor life?<\/p>\n
The site is already emerging as an exciting new location to study Mars\u2019 geologic evolution, search for life and plan future robotic and human exploration. The possible presence of glacial ice at shallow depths near the equator means humans could potentially explore a less frigid part of the planet while still being able to extract water for hydration and manufacturing rocket fuel.<\/p>\n
Reasons to be excited<\/h3>\n
Lee said:<\/p>\n
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It\u2019s really a combination of things that makes the Noctis volcano site exceptionally exciting. It\u2019s 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\u2019 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 glacial 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.<\/p>\n<\/blockquote>\n
Bottom line: A giant volcano on Mars has been hiding in plain sight. It has experienced eruptions in \u201cmodern times\u201d and could erupt again. It\u2019s also the site of glacial ice, which has implications for finding life on Mars or for human exploration of the planet.<\/p>\n
Via SETI<\/p>\n
Read more: More evidence Mars is still volcanically alive<\/p>\n
<\/div>\n
\n - The heavily eroded volcano<\/strong> provides insight into Mars\u2019 evolution over time.<\/li>\n