In the deep waters of Earth’s oceans, scientists have discovered a new species of bacteria that thrives in plumes of underwater hot springs.
It is likely that these hot springs also exist on ocean worlds such as Jupiter’s moon. Europe and the satellite saturn enceladusso these observations sharpen our understanding of the forms extraterrestrial life it could take on those moons, astronomers say.
newly discovered bacteria sulfurimon plumebelongs to a family of organisms that to date had only been known from volcanic fumaroles on Earth’s seabeds, as it cannot tolerate high levels of oxygen in water elsewhere. So scientists were surprised to find a new member, smaller than its relatives, sprouting in oxygen-rich columns of water hundreds of meters away from them.
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“It was a crescendo of excitement to see that these microorganisms were not only abundant but also very active in the spine,” Massimiliano Molari, a scientist at the Max Planck Institute for Marine Microbiology in Germany, told Space.com in an email. Molari was the lead author of the latest study, which found that S pen it has undergone unique genetic changes that allow it to not only adapt but also thrive in a wide range of environments in Earth’s oceans.
One such genetic change has made the bacterium capable of drawing energy from many sources, which is why it is seen in abundance near hydrogen-rich vents on the seafloor, as well as in oxygen-rich plumes thousands of kilometers away. distance, say scientists.
The researchers found that the organism primarily uses hydrogen to multiply and grow ubiquitously. “This has never been observed in this type of environment before,” Molari said.
The global presence of this flexible organism in Earth’s oceans “removes an intellectual barrier to our ability to conceive that something comparable could emerge in other parts of the world.” Solar systemChris German, a senior scientist at the Woods Hole Oceanographic Institution, told Space.com in an email. German was not involved in the study.
This is an exciting discovery, because NASA Casini mission, which studied Saturn and its moons from 2004 to 2017, hydrogen found in the jets that erupted from Enceladus’s south pole as it flew through them, suggesting hydrothermal vent at the bottom of the moon’s ocean, like those on Earth.
Hydrothermal vents form when cold, oxygen-rich seawater seeps through cracks in Earth’s crust and it hisses out again as soon as it encounters the underlying hot magma. The heat triggers chemical reactions that remove oxygen from the water, so it returns to the ocean losing oxygen but gaining other minerals. necessary for microbes to grow.
Scientists divide what happens next into two stages: the resulting hot plume rises hundreds of meters up from the seafloor until it runs out of steam. The plume then extends horizontally for thousands of kilometers, during which time it becomes oxygenated, thanks to mixing with the surrounding oxygen-rich seawater.
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Much of the microbial growth occurs in the second stage, which is also where the study team found abundant S pen in water samples collected from the Arctic and Antarctic oceans. The results of the latest study show that the microbe can survive in all parts of a hydrothermal plume in Earth’s global ocean, according to Morgan Cable, a research scientist at NASA’s Jet Propulsion Laboratory in California and not involved in the study.
Astronomers expect a similar two-stage process from the columns of deep sea volcanoes on the seabed of Europa and Enceladus, although the dimensions and time scales may be different depending on the gravitational attraction of the bodies and how their ocean waters circulate.
So if organisms like S pen exist in the oceans of these moons, the findings of this study “could mean that the probability of detecting evidence of these organisms…is higher than previously thought,” Cable said. “One thing we expect is that if life is present on Europa or Enceladus, there will probably be many different organisms living in a biosphere.”
Scientists hope those organisms will be detected by future missions that will search for life beyond Earth, including NASA’s. Clipper Europewhich will be launched in 2024 to study the habitability of Europe, and the Enceladus Orbilanderwhich will look for signs of life on the surface of that moon.
Any life on these worlds is likely hidden beneath their icy surfaces. So it’s important to consider where the evidence might end up in a condition that would leave it recognizable for the spacecraft to find, German said. The findings of the latest study show that S pen it can survive all the way from its probable origin near seafloor vents to open waters in Earth’s oceans, mixing in different chemical environments as part of the rising and expanding plume.
If a similar life form is present on our solar system’s ocean-hosting moons, the study results “slant the odds in our favor that evidence of any life, such as fuel from seafloor vents, could be preserved.” , intact enough, to reach Earth.” the top of the ocean and toward the surface where we might expect to find it,” German said.
The research is described in a paper (opens in a new tab) published March 9 in the journal Nature Microbiology.
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