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Tag: Astrobiology

  • Scientists Shocked to Discover Microbes ‘Colonizing’ Lava Within Hours of Solidifying

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    Microbes have a penchant to survive almost everywhere on Earth and in the most extreme conditions. This includes the desolate, practically sterile environment following volcanic eruptions.

    In a recent Communications Biology paper, a team of ecologists and planetary scientists report the remarkable ability of microbes to repopulate the landscape nearly immediately after a volcanic eruption. So yeah—we’re essentially talking about microorganisms capable of settling down in freshly cooled lava. Importantly, the study represents the first time scientists have documented microbes moving into a completely new habitat that’s still in the process of forming; the lava, as it pours out from the Earth, effectively clears out anything that was there before.

    Such unique dynamics have potent implications for studying how biological communities evolve, not just on Earth but beyond, according to the researchers in a statement.

    A fiery move

    Previous investigations on microbial resilience had mainly focused on microbes that were either already occupying or had successfully infiltrated a certain habitat, according to the paper. On the other hand, primary succession, or the “transition from an uninhabited to an inhabited environment, has rarely been documented in nature,” it added.

    The researchers wondered if volcanic activity could give rise to such unlikely conditions on Earth and headed over to Iceland to monitor the Fagradalsfjall volcano.

    Study co-author Solange Duhamel stands next to a lava flow during investigations into microbial life near volcanoes. Credit: Christopher Hamilton (University of Arizona)

    “The lava coming out of the ground is over 2,000 degrees Fahrenheit, so obviously it is completely sterile,” Nathan Hadland, study lead author and a doctoral student at the University of Arizona, said in the statement. “It’s a clean slate that essentially provides a natural laboratory to understand how microbes are colonizing it.”

    Between 2021 and 2023—the study period—the volcano erupted thrice, unleashing intense bursts of gas, dust, and lava that engulfed a wide swath of the tundras nearby. Needless to say, the lava rocks contain little to no water or organic nutrients, meaning that, even if the microbes somehow survived the heat of the lava, they wouldn’t have anything to subsist on. But the researchers’ investigations suggested that didn’t really matter.

    “Badass” colonizers

    For their analysis, the researchers collected lava flows as soon as they were cool enough to gather, in addition to rainwater, aerosols, and rocks from surrounding areas. Then, they extracted DNA from these samples to assess whether and where microbes were present. Finally, they monitored the growth of this new microbe population. “Multiple metrics revealed that the lava flows analyzed in this study rapidly hosted microorganisms within hours and days of solidification,” the researchers noted in the study.

    “The fact that we were able to do this three times—following each eruption in the same area—is what sets our project apart,” Hadland said.

    Indeed, the researchers were able to confirm a first wave of “badass” microbes that survive initial conditions within hours and days of a volcanic eruption. These microbes most likely arrived via rainwater, according to the paper.

    As conditions become less extreme with time, more microbes “move in” to the new community from more rain and adjacent areas, the paper explained. The microbial community did experience some declines in winter but overall maintained stability over three different eruptions.

    “We were not expecting that,” said Solange Duhamel, study co-author and a biologist at the University of Arizona. “These lava flows are among the lowest biomass environments on Earth… But our samples revealed that single-celled organisms are colonizing them pretty quickly.”

    Will Martians be microbial?

    For the researchers, an obvious implication of the new study is whether similar biological processes may be at work on Mars. Although the volcanoes on the neighboring planet appear to have settled, scientists now know that it isn’t impossible for tiny organisms to make a home for themselves inside freshly solidified lava.

    Additionally, volcanic activity injects heat into a planet’s system and releases volatile gases, “so the idea is that past volcanic eruptions could have created transient periods of habitability,” Duhamel added.

    That said, all this stuff about Mars is a big assumption, the researchers admitted. But it’s certainly an impressive demonstration that life on the smallest scales will survive in the grandest of ways.

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    Gayoung Lee

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  • New Life-Giving Molecules Found in 17-Year-Old Data From Saturn’s Moon Enceladus

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    The south pole of Enceladus—a tiny moon orbiting Saturn—is a volatile place. In this region, the moon’s subsurface ocean spews jets of water through four “tiger stripe” cracks in the icy crust, culminating in a single plume of ice particles that stretches hundreds of miles into space.

    The Cassini spacecraft spent two decades studying these particles to search for evidence of habitability on Enceladus. In 2008, the probe flew straight through the icy plume to study particles that were ejected only minutes before they hit the spacecraft’s Cosmic Dust Analyzer (CDA). More than 15 years later, scientists have finally deciphered this data, finding that the particles contained organic molecules never seen in Enceladus’s ejections before.

    The study, published Wednesday in the journal Nature Astronomy, explains that the newly detected molecules include those involved in chains of chemical reactions that ultimately give rise to more complex molecules that are essential for life on Earth, according to the researchers.

    “There are many possible pathways from the organic molecules we found in the Cassini data to potentially biologically relevant compounds, which enhances the likelihood that the moon is habitable,” said lead author Nozair Khawaja, a researcher at Freie Universität Berlin, in a statement from the European Space Agency (ESA).

    The search for signs of habitability on Enceladus

    Enceladus’s subsurface ocean has captivated astrobiologists ever since the Cassini mission, a joint endeavor between NASA, ESA, and the Italian Space Agency (ASI), first discovered evidence of it in 2014. Life as we know it can’t exist without water, so a moon with a vast reserve of the stuff is a pretty good place to look for life-giving molecules.

    Cassini orbited Saturn from 2004 to 2017 before dramatically plunging into the ringed planet. During this time, the probe detected many organic molecules—including phosphorus and precursors for amino acids—as it flew through Saturn’s E ring, which is largely made of water-ice ejected from Enceladus.

    However, grains of ice in the E ring can be hundreds of years old. As they age, they may lose some traces of organic molecules present in Enceladus’s subsurface ocean. To get a better understanding of what’s really going on down there, Khawaja and his colleagues set out to analyze data taken from a fresher source.

    Getting closer to the source

    The researchers specifically looked at data Cassini gathered during its foray into Enceladus’s icy plume. The freshly ejected particles slammed into the spacecraft’s CDA instrument at high speed—roughly 11 miles (18 kilometers) per second.

    The speed of impact proved to be equally important as the particles’ freshness. “At lower impact speeds, the ice shatters, and the signal from clusters of water molecules can hide the signal from certain organic molecules,” Khawaja explained. “But when the ice grains hit CDA fast, water molecules don’t cluster, and we have a chance to see these previously hidden signals.”

    This would explain why he and his colleagues uncovered new organic molecules in this data. They also detected some that had already been found in the E ring, confirming that they come from Enceladus’s ocean. This contradicts recent evidence that suggests these molecules may actually stem from radiation-driven chemistry on the moon’s surface and inside its plumes.

    While the findings strengthen the case for Enceladus’s habitability, there is still much work to be done to confirm whether this icy wasteland can support life. ESA aims to launch another mission to explore this distant moon, this time searching for signs of habitability on the surface.

    ​​“Even not finding life on Enceladus would be a huge discovery, because it raises serious questions about why life is not present in such an environment when the right conditions are there,” Khawaja said.

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    Ellyn Lapointe

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  • Reinventing SETI: Why Our Alien-Hunting Playbook Needs an Upgrade

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    In this excerpt from his new book, John Gertz argues it’s time to ditch SETI’s old dogmas and rethink how we prepare for first contact.

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    John Gertz

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