New research suggests that Mars underwent alternating warm and cold periods billions of years ago. These fluctuations, occurring over relatively short intervals, may have influenced the planet’s ability to sustain liquid water. The findings indicate that while Mars was once a wetter world, drastic temperature shifts could have impacted any potential life forms. Scientists continue to explore how Mars’ atmosphere retained warmth despite the planet’s distance from the Sun and the Sun’s lower brightness during its early history.

Study Sheds Light on Martian Climate Variability

According to a study published in Nature Geoscience, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) examined how Mars’ climate evolved. Hydrogen in the planet’s atmosphere is believed to have played a key role in trapping heat, preventing surface water from freezing. This hydrogen, interacting with carbon dioxide, likely created a greenhouse effect similar to Earth’s. However, hydrogen levels should have been short-lived, prompting scientists to model how atmospheric conditions changed over time.

Warm Periods and Their Impact on Mars’ Atmosphere

Danica Adams, NASA Sagan Postdoctoral Fellow, as reported, explained in a statement that their findings suggest Mars experienced episodic warm periods between four and three billion years ago. These temperature fluctuations lasted at least 100,000 years each and repeated over a span of 40 million years. Water loss from the atmosphere to the surface is thought to have replenished hydrogen, sustaining the greenhouse effect for short durations.

Chemical Reactions and Atmospheric Changes

Chemical shifts were also observed, with carbon dioxide breaking down into carbon monoxide under sunlight. During warmer periods, this carbon monoxide reverted to carbon dioxide, helping maintain warming cycles. If cold conditions persisted, carbon monoxide and oxygen would accumulate, altering the atmosphere’s composition.

Future Analysis of Martian Samples

Robin Wordsworth, a researcher at SEAS, reported that the study integrates atmospheric chemistry with climate models to make predictions that can be tested once Martian rock samples are returned to Earth. Scientists hope that further analysis will provide deeper insights into Mars’ past and whether conditions were ever stable enough to support microbial life.