Is Mars the Cradle of Life in Our Solar System?

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At the dawn of our solar system, life may have found a haven not on Earth, but on its neighbour, Mars. New research suggests that the vital building blocks for life were present on the red planet around 4.5 billion years ago.

Mars, a Likely Nursery for Life?

The inception of life requires the presence of organic molecules. Recent studies hint that these crucial constituents existed on Mars about 4.5 billion years in the past. These elements, essential for life, may have journeyed to Earth around the same period. However, it appears that Mars presented a more congenial environment for life.

Mars and Earth: Siblings in the Solar System

Earth and Mars belong to the inner solar system, a family that includes four terrestrial planets and the asteroid belt. Soon after their birth, these rocky siblings withstood a merciless onslaught of asteroids. This cosmic storm rained down on the inner solar system and left a profound impact on both Earth and Mars.

Recycling of Ancient Meteors on Earth

These celestial rocks became part of the crust of both Earth and Mars. However, the plate tectonics on Earth led to the recycling of these ancient meteors into the planet's interior. In contrast, the surface of Mars remained static, preserving the vestiges of the primeval past.

The Revelation of Martian Meteorites

The study of 31 Martian meteorites helped answer pivotal questions about their origin. Earlier, it remained ambiguous whether these antique projectiles originated from the inner or outer solar system, or whether they carried organic material necessary for life's emergence.

Life-Enabling Elements from the Outer Solar System

Using ultrahigh precision chromium isotope measurements, the researchers categorised the meteorites as carbonaceous chondrites from the outer solar system. Considering the typical composition of such rocks and the average ice content, scientists estimated that these primordial impacts delivered enough water to cover the entire Martian surface with a 307-meter deep layer.

The Role of Carbonaceous Chondrites

Notably, carbonaceous chondrites from the outer solar system are known to transport organic molecules like amino acids to the inner solar system. These compounds, crucial for DNA formation, likely supplied the raw materials for life to flourish.

The Cosmic Catastrophe on Earth

While conditions on Mars seemed optimal for life's inception, Earth's environment was less inviting. A cataclysmic event occurred on Earth, believed to be a collision between Earth and a Mars-sized planet. This high-energy clash resulted in the formation of the Earth-Moon system and likely obliterated any potential life on Earth.

Life's Early Chances: Mars vs Earth

Considering these findings, life probably had a better chance of prospering on Mars than on Earth during the formative years of the inner solar system. These fascinating insights offer a fresh perspective on the origin of life in our solar system and the potential for extraterrestrial life on Mars.

Conclusion

The notion that Mars, not Earth, could have been the birthplace of life in our solar system challenges existing theories and opens up new avenues for exploration.

As scientists continue to delve into the mysteries of our solar system, such revelations underscore the importance of ongoing Mars missions and the search for signs of ancient life on the red planet.

This article is based on a study published in the journal Science Advances in November 2022.

References

1. Benjamin Taub. "Could Mars Have Been The Birthplace Of Life In Our Solar System?". IFLScience, 2022.
2. "Could Mars Have Been The Birthplace Of Life In Our Solar System?". Science Advances, 2022.