The Exciting Secret Martian Ice Could Be Hiding

Across generations and continents, people have been searching for proof of life beyond Earth. The possibility of intelligent beings on Mars has been particularly intriguing, which is why the planet has been and still is a prime target for exploration. In a 2024 study published in peer-reviewed journal Communications Earth & Environment, scientists explain how there could be microbes below the frozen surface — an exciting prospect to say the least. The study authors explain that ultraviolet radiation can pass through several meters of Earth ice. In such cases, researchers have found small pools of meltwater teeming with algae, fungi, and other microbes thriving off of photosynthesis. The study authors strongly believe that the same could be found on Mars, one of several planets that have polar ice caps.

The surface isn't protected by ozone, so about 30% more UV light penetrates the atmosphere than our planet — too much for organisms to survive on most of Mars. However, special models of the planet show that habitable zones exist among mid-latitude ice. It's estimated that, with Sun exposure, dense dusty snow can heat up and melt into pockets of water up to a few feet beneath the surface where it's protected from the planet's harsh atmosphere.

This proposal comes after lead author Aditya Khuller of NASA's Jet Propulsion Laboratory and co-author Phil Christensen of Arizona State University published a 2021 paper in the Journal of Geophysical Research: Planets about dusty water ice within Martian gullies. Based on their new conclusions, Khuller says, "If we're trying to find life anywhere in the universe today, Martian ice exposures are probably one of the most accessible places we should be looking" (via JPL).

Currently, the average temperature on Mars is negative 81 degrees Fahrenheit, while the atmospheric surface consists of 95.3% carbon dioxide — a combination that makes liquid water unstable. As if that wasn't inhabitable enough, UV radiation wreaks havoc on the surface because there's no magnetic field to disrupt it. However, most experts agree that the conditions may not have always been so bleak.

According to a 2022 study led by researchers from the University of Arizona and published in Nature Astronomy, Mars likely had a much denser atmosphere during its infancy 4 billion years ago. The hydrogen and carbon dioxide would have likely allowed water to flow and methanogenic microbes to live underground like they do on Earth. When it lost its magnetic field about 3 billion years ago, though, the Sun stripped most of the atmosphere away, which is why the planet is a cold, dry desert now.

Plus, surface investigations have confirmed the presence of water on Mars. NASA landed a probe on Mars in 2018, and the InSight seismometer identified an earthquake caused by a meteoroid strike that revealed underground water ice, which future astronauts could use as a source of water for drinking and growing food. Since landing in 2021, NASA's Perseverance rover has sampled ancient lake beds and discovered more about the history of water on the planet. Additionally, the rover's special equipment successfully produced oxygen from carbon dioxide, progressing the goals of future exploration (and possibly even laying foundations for the first cities on Mars).