Microbes thriving in Mauna Loa's lava tubes offer clues about Martian life

Could similar life exist in Martian lava tubes?

Researchers believe that when lava tubes first formed on Mars, the Red Planet was likely similar to Earth, with active volcanoes, an atmosphere, a warmer climate, and flowing water.

These conditions may have nurtured life on Mars, much like on Earth. Despite the Martian surface becoming inhospitable to life around 3 billion years ago, it's possible that microbes migrated underground and still exist today in Martian lava tubes.

The team's findings, published in the Journal of Geophysical Research: Planets, significantly impact our understanding of life on Mars. As we continue to explore the Red Planet, the knowledge gained from Mauna Loa's lava tubes will help guide future missions searching for ancient or current microorganisms.

A glimpse into the life on Mars

Amy McAdam, a geochemist at NASA’s Goddard Space Flight Center and the Curiosity rover's science team member, said in a press release:

"We have identified minerals similar to those found at Mauna Loa on the Martian surface and right below it." This connection between the two planets suggests that Mauna Loa's lava tubes could provide valuable information on potential life-supporting environments on Mars.

Back in the lab, Fishman sequenced the genomes of 72 new organisms found within the Mauna Loa lava tubes. This ongoing analysis will help classify these microbes based on their characteristics and further our understanding of their survival strategies.

As we continue to explore the Martian landscape, the discoveries made in Hawaii's Mauna Loa volcano will prove invaluable. The microbes thriving in the depths of Earth's largest active volcano offer a glimpse into the possibilities of life on Mars, bringing us one step closer to uncovering the secrets of the Red Planet.

The expedition's findings were published in JGR Planets and can be found here.

Study Abstract:

Lava tubes are key targets in the search for life on Mars. Their basaltic walls provide protection from radiation and changing environmental conditions, which could enable life or preservation of previous life in an otherwise harsh environment. We can understand the potential for Martian life in lava tubes by studying the habitability of analog environments on Earth. In this study, we present the first characterization of the microbial life inside a pristine Mauna Loa lava tube. This study is the first to combine 16S SSU rRNA sequencing and whole genome shotgun (WGS) sequencing to map the taxonomic makeup and functional potential of any lava tube community in Hawaii, enabling a deep understanding of the types of microbes that thrive in this unique environment and the metabolisms they use. We find a surprisingly high degree of niche partitioning over small spatial scales and discuss implications for life detection strategies. Based on recent bioinformatic advancements in metagenomics, we also assemble dozens of high-quality metagenome assembled genomes (MAGs) from the microbes living in the lava tubes, including several novel species.