Speaker 1: Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff,
Speaker 1: Lauren Vogel bomb here. When it comes to searching for
Speaker 1: microbes on Mars, sending a robotic rover to the most
Speaker 1: arid environment on Earth is a fine place to start.
Speaker 1: As described in a study recently published in the journal
Speaker 1: Frontiers and Microbiology, a team of researchers explored the extreme
Speaker 1: environment of Chile's Atacama Desert. They wanted to develop strategies
Speaker 1: that future robotic explorers could use to seek out the
Speaker 1: hiding places of Martian microbes. Both NASA and the European
Speaker 1: Space Agency will launch their first life hunting rovers to
Speaker 1: the Red planet, the Mars Exo Mars Rover missions, respectively,
Speaker 1: so mission managers will need to know where to look.
Speaker 1: The Atacama Desert is about as extreme as it gets
Speaker 1: for life to eke out an existence, and not only
Speaker 1: is the region bone dry, the core of the desert
Speaker 1: doesn't get any rainfall for decades at a time, but
Speaker 1: because of its elevation, it also receives high levels of
Speaker 1: damaging ultraviolet radiation. Plus the soil is extremely salty. These
Speaker 1: factors should make the Atacama Desert toxic for life, but
Speaker 1: according to team leader stuff In Pointing, a professor at
Speaker 1: Yale and US College in Singapore, some of the bacteria
Speaker 1: just below the surface quote survive right at the limit
Speaker 1: of habitability, and this is very good news for the
Speaker 1: prospect of finding microbes on Mars. Pointings team deployed an
Speaker 1: autonomous rover mounted drill and sampling device in the Atacama
Speaker 1: Desert to see if it could extract soil samples containing
Speaker 1: microbes down to a depth of eight centimeters that's a
Speaker 1: little over two and a half feet. As a comparison,
Speaker 1: samples were also dug up by hand through DNA sequencing.
Speaker 1: The researchers found that the bacterial life and the samples
Speaker 1: from both methods were similar, confirming that these hardy bacteria
Speaker 1: exist and the autonomous extraction method was successful. This test
Speaker 1: run shores up hope that if similarly hardy microbes also
Speaker 1: thrived just below the Martian surface, a robot could find them. However,
Speaker 1: finding microbial biosignatures on Mars could be very challenging for
Speaker 1: a remotely operated Mars rover. The researchers found that the
Speaker 1: subsurface population of bacteria were extremely patchy, correlating with increased
Speaker 1: salt levels that restricted the availability of water. Pointing put
Speaker 1: it this way, The patchy nature of the colonization suggest
Speaker 1: the rover would be faced with a needle in a
Speaker 1: haystack scenario. In the search for Martian bacteria, previous studies
Speaker 1: have described the ubiquitous population of relatively unremarkable photosynthetic bacteria
Speaker 1: that populate the surface of the desert in Chile. These
Speaker 1: are microorganisms that get their energy from sunlight. Things start
Speaker 1: to get a lot more interesting and indeed more alien,
Speaker 1: just below the surface, Pointing said, we saw that with
Speaker 1: increasing depth, the bacterial community became dominated by bacteria that
Speaker 1: can thrive in extremely salty and alkaline soils. They in
Speaker 1: turn were replaced at depths down to eighty centimeters by
Speaker 1: a single specific group of bacteria that survived by metabolizing methane.
Speaker 1: These specialized microbes have been found before in deep mind
Speaker 1: shafts and other subterranean environment, but they've never been seen
Speaker 1: beneath the surface of an arid desert. Pointing said, the
Speaker 1: communities of bacteria that we discovered were remarkably lacking in complexity,
Speaker 1: and this likely reflects the extreme stress under which they develop.
Speaker 1: Finding highly specialized microbes that can thrive in the extremely dry,
Speaker 1: salty and alkaline Mars. Like soils in the Atacama Desert
Speaker 1: suggest methane utilizing bacteria could also thrive on the Red planet.
Speaker 1: Elevated levels of methane have been observed on Mars by
Speaker 1: various spacecraft over the years, most recently measures made by
Speaker 1: NASA's Curiosity Rover, and that's a big deal. On Earth,
Speaker 1: biological and geological processes generate methane, and in turn, microbes
Speaker 1: can metabolize methane for energy. The discovery of methane in
Speaker 1: the Martian atmosphere could mean there's some kind of active
Speaker 1: biology going on underground. To confirm this, we need microbe
Speaker 1: seeking missions that will drill below the surface, and now
Speaker 1: we have a strategy to track them down. Should microbial
Speaker 1: life be found on Mars, it would undoubtedly be the
Speaker 1: most significant scientific discovery in human history. But in the
Speaker 1: proud human tradition of naming new things, what would we
Speaker 1: call our newly discovered Martian neighbors? Would we just copy
Speaker 1: the system of how we name life on Earth? Pointing said,
Speaker 1: the way we assign Latin names to terrestrial bacteria is
Speaker 1: based on their evolutionary relationship to each other, and we
Speaker 1: measure that using their genetic code. The naming of Martian
Speaker 1: bacteria would require a completely new set of Latin names
Speaker 1: at the highest level, if Martian bacteria were a completely
Speaker 1: separate evolutionary lineage, that is, they evolved from a different
Speaker 1: common ancestor to Earth bacteria in a second genesis event. Granted,
Speaker 1: if we find the genetic code of Mars life to
Speaker 1: be similar to Earth life, it could be that life
Speaker 1: was transferred from Earth to Mars in the ancient past
Speaker 1: via a massive impact, a mechanism known as pan spermia.
Speaker 1: But if we find a truly novel genetic code that
Speaker 1: emerged on Mars, the implications for our understanding of life
Speaker 1: would be profound. Pointing said, if we find truly native
Speaker 1: Martian bacteria, I would love to name one and call
Speaker 1: it planet a desert a supersities, which translates in Latin
Speaker 1: to survive on the desert planet. Today's episode was written
Speaker 1: by Ian O'Neill and produced by Tyler Clain for iHeartMedia
Speaker 1: and How Stuff Works. For more on this and lots
Speaker 1: of other hardy topics, visit our home planet how stuff
Speaker 1: Works dot Com.