Breakthrough: Scientists find potential signs of life in mantle rocks during expedition.
During a 47 – day research expedition in the middle of the Atlantic, an international team of scientists have managed to collect an unparalleled amount of rock samples from the shallow mantle of the oceanic crust. The team was led by Co-Chief Scientist Dr. Gretchen Früh-Green ( ETH Zurich, Switzerland) and Dr. Beth Orcutt (Bigelow Laboratory for Ocean Sciences, USA), with the aim to determine how mantle rocks are brought to the seafloor and react with water (serpentinization).
At such depths where sunlight does not penetrate, these type of reactions which create immense amounts of heat may be the key to helping life flourish. The findings may also help the scientists learn about the origins of life and how it may have coped during the early stages of Earth history.
“The rocks collected on the expedition provide unique records of deep processes that formed the Atlantis Massif. We will also gain valuable insight into how these rocks react with circulating seawater at the seafloor during a process we call serpentinization and its consequences for chemical cycles and life” -Co-Chief Scientist Gretchen Früh-Green
Fellow leading scientist Beth Orcutt further states that during the drilling process, they found evidence for hydrogen and methane in the samples, which microbes ‘consume’ to grow and create new cells.
“Similar rocks and gases are found on other planets, so by studying how life exists in such harsh conditions deep below the seafloor, we inform the search for life elsewhere in the Universe.” – Beth Orcutt
It’s important to note that even though the findings in the expedition could point to signs of life, the scientists have yet to constrain the nature and distribution of the methane and hydrogen found.
The findings from expedition 357 are promising, as we know there are planetary bodies in the Universe which mimic some of the harsh conditions here on Earth. If the hydrogen and methane found in the mantle rocks are indeed from life-based organisms, then it opens up doors for potential life-based organisms on other planets.
The International Ocean Drilling Program
The 47- strong team of scientists form part of the International Ocean Drilling Program (IODP), and were part of Expedition 357 titled; Atlantic Massif Serpentinization and Life Expedition. The expedition lasted 53 days ( 26th October – 11th December 2015) and used the drillship, RRS James Cook, carrying the BGS Rockdrill 2 and the MARUM-MeBo seafloor drills.
The IOPD is an international collaboration of scientists and organisation with the aim to recover geological data and samples from beneath the ocean floor to study the history and dynamics of Planet Earth. The IODP is important for the international geological community, as it gives invaluable insight to dynamic Earth processes which are hard to witness on the surface.
The IODP runs many expeditions a year, having only just completed one on the 31st January 2016. Named Expedition 360 and titled the Indian Ridge Moho Expedition, the aim was to try and drill through the Atlantis Bank Massif into the mantle. The first objective was to recover the lowermost mantle rocks (Gabbros) and crust-mantle transition to understanding the processes behind the creating of the Mid-Ocean Ridge. The second objective was to ultimately settle the controversy as to whether the Moho at the spreading ridges can be a serpentinized front.
Stay tuned with Flavible to hear more about the latest expedition. This article will be updated as more details emerge.