Scientists Suggest That Mars Was Warm and Held Water Billions of Years Ago, Much More Like Earth in the Past

Researchers have finally solved the mystery of persistent hydrogen in the Martian atmosphere. They have also figured out that Mars experienced fluctuating climate spells in the past, stated Space dot com. Past findings have concluded that dry Mars once had rivers. This discovery intrigued researchers as it implied that there was the possibility of life on this planet amidst water. The reason for the fluctuating climate was often cited to be the presence of hydrogen, but what perplexed researchers was that analysis indicated that hydrogen should not exist for so long in Martian conditions. The findings published in Nature Geoscience present a theory on how this element managed to exist.

The past presence of rivers could not be attributed to the sun because of Mars' distance from the star and the less power it had at that time. "It's been such a puzzle that there was liquid water on Mars, because Mars is further from the sun, and also, the sun was fainter early on," team leader Danica Adams, NASA Sagan Postdoctoral Fellow said. "It makes a really great case study for how planets can evolve over time." Researchers after examination cited the interaction of hydrogen with carbon atoms as the reason behind the presence of rivers.
According to scientists, hydrogen and carbon atoms combined to form carbon dioxide in the ancient Martian atmosphere. Carbon dioxide is a greenhouse gas, meaning that it traps heat, making the planet warm enough to generate liquid water. The issue they faced with the assertion was that Mars' condition should not have allowed atmospheric hydrogen to sustain for a long duration.

(Image Source: Nature Geoscience)
To understand why that could have been the case, experts applied models used by experts to track pollutants on Earth in this study. "Early Mars is a lost world, but it can be reconstructed in great detail if we ask the right questions," Robin Wordsworth, the Gordon McKay Professor of Environmental Science and Engineering explained, according to Science Direct. "This study synthesizes atmospheric chemistry and climate for the first time, to make some striking new predictions -- which are testable once we bring Mars rocks back to Earth."
The model noted how hydrogen mixed and interacted with other gases in the Martian atmosphere and chemicals on its surface. The model showcased to them that Mars experienced episodes of warm climate around three to four billion years ago. Each of these spells lasted for around 100,000 years. Researchers believe the warmth was facilitated by Mars losing water from the atmosphere to the ground. The same water replenished the hydrogen content of the Martian environment, thus keeping the Greenhouse effect in play.
Mars was hot then cold then hot again. Could life have really survived there? https://t.co/7PWd21Fjdi
— Lucas Samuel (@LucasSa54749430) January 31, 2025
The temperature fluctuation on Mars has also been noted in chemical processes that existed millenniums ago on this planet. During the cold spells, carbon dioxide reacted with sunlight and produced carbon monoxide. In the warm period, the process will continue and carbon monoxide will turn to carbon dioxide. "We've identified time scales for all of these alternations," Adams said. "And we've described all the pieces in the same photochemical model." The recycling process beginning with carbon dioxide hampered the levels of oxygen during the cold period, which could have caused problems for any possible life on the planet at that time, as per researchers.