Strange climate changes have been detected on Mars: could life have survived there?

Researchers have discovered that temperatures on Mars in the distant past could fluctuate between brief hot and cold periods. However, these temperature changes could have been detrimental to any life that may have existed on the Red Planet. The study is published in the journal Nature Geoscience, as reported by Space.

Scientists understand that despite Mars being a cold and arid planet today, billions of years ago it resembled Earth more closely, with a warmer and wetter climate. The new research reveals how liquid water could have existed on Mars and the planet could have been warm.

According to the researchers, it has long been a mystery how liquid water could have existed on Mars, given that the planet is located further from the Sun. Moreover, billions of years ago, the Sun emitted less heat.

Previously, scientists believed that liquid water on Mars could be attributed to the presence of a significant amount of hydrogen in the planet's atmosphere.

Hydrogen could bond with carbon atoms to create carbon dioxide in the atmosphere. As is known, this greenhouse gas retains heat and causes the greenhouse effect. Thus, this could have allowed for liquid water to exist on the surface of Mars. However, the issue is that hydrogen in the Martian atmosphere could not persist for very long.

The authors of the study created a model to determine how the hydrogen content in Mars' atmosphere changed over time. The researchers simulated how hydrogen mixed and reacted with other gases in the Martian atmosphere and with chemical substances on the planet's surface.

The results indicated that episodic warm periods existed on Mars approximately 3-4 billion years ago. These warm periods alternated with cold ones over a span of about 40 million years, with each warm period lasting no less than 100,000 years.

Scientists suggest that the emergence of warm and humid periods could have been due to water from the Martian atmosphere reaching the surface, thus replenishing the hydrogen content in the atmosphere. This, in turn, sustained the greenhouse effect.

The authors of the study believe that carbon dioxide continuously reacted with sunlight, leading to the formation of carbon monoxide. However, during warm periods, it would revert back to carbon dioxide.

This process would cease if Mars remained cold for a sufficiently long time, resulting in the accumulation of carbon monoxide and oxygen.

Currently, researchers want to know if there was any form of life, even microbial, on Mars in the distant past. However, the temperature changes could have been harmful to life if it existed on the Red Planet.

In the future, the authors of the study plan to compare their models with actual soil samples collected from Mars, which are expected to be brought back to Earth in the next decade.