Extremophile Bacteria: Potential Hitchhikers on Asteroid Debris

Recent research highlights an extraordinary extremophile organism, Deinococcus radiodurans, known for its remarkable resilience. This unique microbe can endure the harsh conditions of radiation, frigid temperatures, and arid environments typically encountered during interplanetary transport. New findings suggest that Deinococcus radiodurans also possesses outstanding resistance to the extreme transient pressures generated by impact ejection from Mars. Consequently, this raises the possibility that such resilient life forms could traverse between planets in our solar system following a significant asteroid impact.

Artist’s impression of an asteroid. Image credit: Mark A. Garlick, Space-art.co.uk / University of Warwick / University of Cambridge.

Impact craters are prevalent on the surfaces of numerous celestial bodies, with the Moon and Mars being among the most cratered.

Scientific findings indicate that asteroid impacts can propel materials across space, as evidenced by the discovery of a Martian meteorite on Earth.

Furthermore, researchers have long speculated that asteroids could also launch microscopic life forms into space.

This theory, known as the lithopanspermia hypothesis, suggests that life could be ejected into space and potentially land on other planets.

In a groundbreaking study, researchers from Johns Hopkins University, led by Kariat (KT) Ramesh, simulated conditions under which microbes like Deinococcus radiodurans could be expelled into space due to an impact force.

The researchers placed the bacteria between two steel plates and applied pressure with a third plate, demonstrating that these microbes can withstand pressures of up to 3 GPa (30,000 times Earth’s atmospheric pressure).

By analyzing gene expression, they were able to observe biological stress responses within the bacteria under varying pressures.

While samples subjected to 2.4 GPa started to exhibit membrane damage, the unique structure of the bacterial cell envelope accounts for a survival rate of 60% among the microorganisms.

The transcriptional profiles indicated that these resilient bacteria prioritize repairing cellular damage in the aftermath of an impact.

Deinococcus radiodurans. Image credit: USU/Michael Daly.” width=”580″ height=”389″ srcset=”https://cdn.sci.news/images/2024/12/image_13511-Deinococcus-radiodurans.jpg 580w, https://cdn.sci.news/images/2024/12/image_13511-Deinococcus-radiodurans-300×201.jpg 300w, https://cdn.sci.news/images/2024/12/image_13511-Deinococcus-radiodurans-84×55.jpg 84w” sizes=”(max-width: 580px) 100vw, 580px”/>

Deinococcus radiodurans. Image credit: USU/Michael Daly.

“While we have yet to confirm the existence of life on Mars, if it exists, it likely shares similar survival capabilities,” Ramesh remarked.

“This study suggests that life could endure being ejected from one planet and travel to another.”

“These findings significantly alter our understanding of the origins of life on Earth,” remarked Dr. Lily Chao, also from Johns Hopkins University.

“Our research indicates that life can survive massive impacts and eruptions, implying that life may travel between planets. Perhaps we are all Martians!”

These findings were published in this week’s edition of PNAS Nexus. For detailed insights, refer to the study.

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Lily Chao et al. 2026. Extremophiles can withstand temporary pressures associated with impact ejection from Mars. PNAS Nexus 5(3):pgag018; doi: 10.1093/pnasnexus/pgag018.

Source: www.sci.news

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