When it comes to humanity, Earth is considered humans’ original birthplace. But a new radical theory not only upends this long-standing view about the humans’ origin but also deepens the mystery.
The Martian ancestry theory suggests that humans could have come from Mars, as suggested by the scientists from Johns Hopkins University.
Astrobiologists have long thought that life can travel between planets when asteroids crash, launching various life forms, a theory known as the lithopanspermia hypothesis.
But the researchers were previously clueless about whether the microbes could survive the impact and hazardous trip through space.
In a recent experiment in which the scientists fired projectiles at the ultra-resilient bacterium Deinococcus radiodurans, they found that these microbes can survive the extreme pressure and shock of being ejected from a planet’s surface during an asteroid impact.
According to the findings published in the journal PNAS Nexus, Deinococcus radiodurans survived pressures of up to three gigapascals which is 30 times the pressure of the Mariana Trench.
“We expected it to be dead at that first pressure. We started shooting it faster and faster. We kept trying to kill it, but it was really hard to kill,” Dr Lily Zhao, the lead author and a Nasa fellow at Johns Hopkins, said.
Given the habitable nature of Mars due to presence of liquid water, the researchers suggested that Earthly life, including humans, could be originally descended from Martian microbes.
If we consider the possibility of interplanetary microbial travel, Mars stands out as a compelling potential cradle for life that eventually took root on Earth.
“We have shown that it is possible for life to survive large-scale impact and ejection. What that means is that life can potentially move between planets. Maybe we’re Martians,” Zhao said.
It is impossible to deny that the Red Planet was once a habitable place. Last year, NASA’s Perseverance rover discovered leopard-spot markings on rock containing organic compounds, signalling the presence of potential lifeforms on Mars.
According to Prof Kaliat Ramesh, the senior author of Johns Hopkins, the ground-breaking study could change the way we think about the origin of life and how life began on Earth. It could also change the perspective regarding the origin of humanity.
The findings have major implications for space missions. If hardy microbes can survive interplanetary travel, NASA and other agencies must be stricter about "contaminating" other planets or moons that are currently considered sterile.