September 11, 2025
While the early Mars local weather stays an open query, a brand new examine suggests its ambiance could have been hospitable to life attributable to volcanic exercise which emitted sulfur gases that contributed to a greenhouse warming impact.
This discovering comes from a examine revealed in Science Advances, led by researchers at The University of Texas at Austin.
Using knowledge from the composition of Martian meteorites, the researchers ran greater than 40 pc simulations with diversified temperatures, concentrations, and chemistry to estimate how a lot carbon, nitrogen, and sulfide gases could have been emitted on early Mars.
Instead of the excessive concentrations of sulfur dioxide (SO₂) that earlier Mars local weather fashions predicted, their analysis exhibits volcanic exercise on Mars round 3-4 billion years in the past could have led to excessive concentrations of a variety of chemically “reduced” types of sulfur – that are extremely reactive. This consists of sodium sulfide (H₂S), disulfur (S₂) and presumably sulfur hexafluoride (SF6) – a particularly potent greenhouse fuel.
According to guide writer Lucia Bellino, a doctoral pupil on the UT Jackson School of Geosciences, this may increasingly have made for a singular Martian atmosphere – one that will have been hospitable to sure types of life.
“The presence of reduced sulfur may have induced a hazy environment which led to the formation of greenhouse gases, such as SF6, that trap heat and liquid water,” stated Bellino. “The degassed sulfur species and redox conditions are also found in hydrothermal systems on Earth that sustain diverse microbial life.”
Previous Mars research have researched how the discharge of gases on the floor, usually by way of volcanic eruptions, could have impacted the planet’s ambiance. In distinction, this examine simulated how sulfur modified because it moved all through geologic processes, together with the way it separated from different minerals because it was included into magma layers beneath the planet’s crust. This is vital as a result of it offers a extra lifelike sense of the chemical state of the fuel earlier than it’s launched on the floor the place it will probably form the early local weather circumstances of Mars.
The examine additionally revealed that sulfur could have been incessantly altering varieties. While Martian meteorites have excessive concentrations of decreased sulfur, the Martian floor accommodates sulfur that’s chemically bonded to oxygen.
“This indicates that sulfur cycling – the transition of sulfur to different forms – may have been a dominant process occurring on early Mars,” stated Bellino.
Last 12 months, whereas the group was within the midst of its analysis, NASA made a discovery that appeared to again their findings. NASA’s Curiosity Mars rover rolled over and cracked open a rock, revealing elemental sulfur. While Mars is thought for being wealthy in sulfurous minerals, it was the primary time the mineral had been present in pure kind, unbound to oxygen.
“We were very excited to see the news from NASA and a large outcrop of elemental sulfur,” stated Chenguang Sun, Bellino’s advisor and an assistant professor on the Jackson School’s Department of Earth and Planetary Sciences. “One of the key takeaways from our research is that as S₂ was emitted, it would precipitate as elemental sulfur. When we started working on this project, there were no such known observations.”
As the group strikes ahead, they’ll use their pc simulations to research different processes that might have been important to maintain life on Mars, together with the supply of water on early Mars, and whether or not volcanic exercise might have supplied a big reservoir of water on the planet’s floor. They additionally search to grasp whether or not the decreased types of sulfur could have served as a meals supply for microbes in an early local weather that resembled Earth’s hydrothermal techniques.
Mars is much from the Sun, and in the present day, it’s usually chilly with a mean temperature of -80 levels Fahrenheit. Bellino hopes that local weather modeling consultants can use her group’s analysis to foretell how heat the early Mars local weather might need been, and, if microbes have been current, how lengthy they might have existed in a hotter ambiance.
The analysis was funded by The University of Texas at Austin Center for Planetary Systems Habitability, the National Science Foundation, and the Heising-Simons Foundation.
For extra info, contact: Anton Caputo, Jackson School of Geosciences, 210-602-2085; Monica Kortsha, Jackson School of Geosciences, 512-471-2241; Julia Sames, Department of Earth and Planetary Sciences, 210-415-9556.