New research examines whether life began on Mars before reaching Earth, calling into question known biological origins.
A new scientific analysis brings back to the fore the debate over the possibility that life on Earth may have first appeared on Mars, according to Mediafax.
The study re-examines the controversial idea that the first microorganisms formed on the Red Planet, later arriving on Earth via meteorites.
Mars’ early advantage over a violent Earth
Researchers show that Mars and Earth formed almost simultaneously, more than 4.5 billion years ago.
However, Earth’s early history was marked by catastrophic impacts, including the collision that formed the Moon and could have sterilized the planet.
Mars appears to have been spared such extreme events, which would have allowed it to retain liquid water, a denser atmosphere, and active hydrothermal systems earlier.
These conditions could have favored prebiotic chemistry and possibly the emergence of life earlier on Mars than on Earth.
Pangenesis and the Martian origin hypothesis
The idea that life traveled between planets is known as the pangenesis or panspermia hypothesis.
The study analyzes genetic clues related to LUCA, the last universal common ancestor of all known life forms.
LUCA’s features suggest adaptation to extreme temperatures and radiation, conditions compatible with the Martian environment in the distant past.
If Earth was temporarily uninhabitable after the big impacts, Mars could have served as a refuge for early life forms.
Asteroid impacts could have thrown rock fragments containing microbes, which later reached Earth.
Could life have survived the journey through space?
The proposed transfer would have been extremely harsh, involving violent ejection, exposure to radiation, freezing and atmospheric reentry.
However, laboratory experiments and space missions have shown that some microorganisms can survive vacuum, radiation and extreme temperatures.
Microbes protected inside rock fragments could have withstood long interplanetary journeys.
Although the probability remains low, scientists say the scenario is no longer considered impossible.
An open question with deep implications
The study acknowledges that the emergence of life directly on Earth remains the simplest explanation.
However, the lack of definitive evidence keeps the Martian origin hypothesis viable.
With future missions to Mars and advances in astrobiology, researchers hope to uncover clues that will definitively clarify where life began.
