Mars is covered in layers and layers of dust, much like an old house that hasn’t been lived in for a long time. However, unlike an uninhabited mansion, imagining life flourishing on the lonely and hazy Red Planet may appear absurd.
Nonetheless, scientists have long believed that our neighbouring world, with its massive craters that may have once been lakes and volcanoes that haven’t erupted in the last 50,000 years, once supported life — even if it was only microbial life.
A recent study conducted by a team at the University of Copenhagen discovered that not only was Mars once covered in water, but it was also most likely the first planet in our solar system to host life.
Water and amino acid-carrying asteroids bring life
There are theories about how giant icy asteroids brought life to Earth, and the same could be said for Mars. According to the study, Mars was bombarded with asteroids covered in ice and possibly organic molecules that are biologically important for life 4.5 billion years ago — about 100 million years after it formed.
The study also suggests that there was enough water to cover the entire planet, confirming the findings of another recent study.
“Our study suggests that two of the important ingredients that can lead to life evolving were present on Mars. Water and complex organic chemistry are involved. So it would be impossible to evolve life on a planet without those two ingredients,” said Professor Martin Bizzarro of the Centre for Star and Planet Formation.
The researchers examined meteorite fragments of Martian crust discovered on Earth, the result of an asteroid or comet slamming into Mars so hard that rocks and other debris launched into space billions of years ago eventually landed on Earth. As a result, they were able to conclude that the Red Planet was once wet.
Mars is much smaller than Earth and lacks the same tectonic plates as Earth’s interior, which is constantly moving and recycling — a process that has erased all evidence of what happened in our planet’s first 500 million years.
However, the Red Planet is essentially bombarded by cosmic radiation, rendering its surface mostly sterile. So, if there is still life on Mars today, it should be 1 to 2 metres deep, according to Bizzarro.
This new study backs up previous research that Mars once had oceans and may have been a suitable environment for life to begin — possibly even before Earth.