New data points to microbial life, water and volcanoes on Mars։ Why is it important?

Utilizing spacecraft images and ground-penetrating radar data, a team from the University of Arizona's Lunar and Planetary Laboratory has generated 3D reconstructions of lava flows in Mars' Elysium Planitia. The researchers identified evidence suggesting that lava erupted through fissures as recently as one million years ago, covering a region on the Red Planet equivalent in size to Alaska.

The team identified over 40 volcanic events, with the largest one appearing to have filled the Martian valley known as Athabasca Valles with nearly 1,000 cubic miles (4,168 cubic kilometers) of basalt. These findings may have implications for Mars' potential to support life as we understand it.

"Elysium Planitia was much more volcanically active than previously believed and might even remain volcanically active today," stated Joana Voigt, team co-leader and scientist at the Lunar and Planetary Laboratory. "Areas like Elysium Planitia, once considered featureless and uninteresting, are now open books that offer a wealth of information about their formation if you know how to interpret them."

Mars is red, not dead 

In contrast to Earth, Mars lacks plate tectonics, the geological phenomenon where sections of the crust shift and resurface, leading to volcanic activity at plate boundaries. This absence has led to Mars being often characterized as a "dead" planet with limited geological activity. However, recent findings challenge this notion.

Although active volcanism hasn't been directly observed on Mars, data from the NASA InSight lander, operational from 2018 to 2022, revealed frequent "marsquakes," indicating ongoing seismic activity beneath the planet's surface.

Just last year, a team of scientists from the University of Arizona presented evidence of increased temperature magma in an area known as a "mantle plume" under Elysium Planitia, driving significant seismic and volcanic events in the recent past.

To conduct a recent study and create a 3D model of such activity, the Lunar and Planetary Laboratory team utilized images from NASA's Mars Reconnaissance Orbiter (MRO), taken by the Context camera, and high-resolution images from the MRO's HiRISE camera. This data was integrated with information from the Mars Orbiter Laser Altimeter on NASA’s Mars Global Surveyor and subsurface radar measurements from NASA's Shallow Radar (SHARAD) probe.

This comprehensive approach allowed them to explore as deep as 460 feet (140 meters) beneath Mars' surface, providing a 3D perspective of the region before lava erupted from fissures.

Christopher Hamilton, team co-leader and scientist at the Lunar and Planetary Laboratory, emphasized, "Our study provides the most comprehensive account of geologically recent volcanism on a planet other than Earth. It is the best estimate of Mars’ young volcanic activity for about the past 120 million years, corresponding to when the dinosaurs roamed the Earth at their peak to the present."

Water and life on Mars

The team's discoveries hold significance for the exploration aimed at determining whether Mars could have supported microbial life in the past. Water, a crucial component for life as we understand it, played a vital role on the Martian surface, which, despite its current barren state, once flowed with abundant liquid water.

Elysium Planitia is identified as a region that likely witnessed extensive floods of liquid water, and there are indications that when lava entered this area, it interacted with the liquid water—or, at the very least, water ice. This interaction is believed to have significantly shaped the landscape of Elysium Planitia.

The team from the Lunar and Planetary Laboratory uncovered ample evidence of steam explosions occurring where potential water met lava. Such interactions can create hydrothermal environments—areas where water is heated by geological activity. Comparable phenomena on Earth include hydrothermal vents on the seabed, sustaining a diverse array of life forms.

Identifying regions of hydrothermal activity on Mars could aid in pinpointing areas conducive to microbial life. The volcanic activity observed by the team in the Elysium Planitia region may have also brought potentially life-sustaining water to Mars' surface through two mechanisms. Firstly, volcanic eruptions could have released a significant amount of groundwater, and secondly, water contained in lava might have been propelled into the atmosphere, freezing and eventually falling back to the ground as ice.

Christopher Hamilton noted, "When there is a crack in the Martian crust, water can flow onto the surface. Because of the low atmospheric pressure, that water is likely to literally just boil away. But if there’s enough water coming out during that period, you can get a huge flood that comes through, racing over the landscape and carving out these huge features that we see."

Furthermore, comprehending the past flow of water on Mars is crucial for planning crewed missions to the Red Planet. Equatorial regions like Elysium Planitia are more accessible for landing than higher latitudes, and knowledge of water sources, even below the surface, could assist future astronauts in obtaining water for consumption or fuel generation during missions.

The team plans to continue their study of this region, utilizing diverse imaging methods to gather extensive data and create additional 3D insights into the Martian surface and its underlying regions. This ongoing research will contribute to constructing a chronological sequence of events for other volcanically active areas on Mars.