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January 28, 2017

‘Alien’ life could exist high in Earth’s atmosphere

What if alien organisms are hiding in plain sight, high above the planet’s surface in our own atmosphere? It’s a question that researchers will attempt to solve later on this year, and it may have implications on how we search for microbial life on other planets as well.

According to Seeker, a team of students from the University of Houston plan to launch a high-altitude experiment as part of a mission to study auroras that is scheduled to lift off from Alaska in March. Their experiment, which the website said “looks almost like a small laundry hamper,” will search for microbes in the atmosphere 11-31 miles (18-50 km) from the ground.

Once it reaches its target altitude, the instrument will open up to collect samples, then close as the balloon-equipped experiment begins to descend. The students believe that this system will be less likely to become contaminated than more complicated systems, but since it has not yet been tested, they are not 100% certain exactly how well it will perform in high altitude conditions.

“A lot of times, these microbes when they go up there, they shut down. They are not replicating and they are not metabolically active,” Houston student and project team member Jamie Lehnen told Seeker on Friday. “I’m interested in how their stress response is similar to those [microbes] back on Earth's surface."

Research could impact search for life on other planets

Roughly two months after the Houston team’s experiment, NASA plans to conduct a study of their own: the ABoVE (Arctic-Boreal Vulnerability Experiment), which according to Seeker is set to run in May and June and will involve using a Gulfstream III jet to monitor how changing climate conditions are affecting plants, animals and the environment as a whole.

David Smith, a microbial researcher at the US space agency, will fly with the ABoVE team to study the microorganisms that travel in a massive spring airstream that move along the Pacific Ocean. As he told the website, he and his colleagues hope to find out what organisms are being carried across the ocean along with the dust and  aerosol particles moved by that airstream.

The research project “will allow us an opportunity to test the atmospheric bridge hypothesis, which simply speaking, is continents sneezing on each other,” Smith explained, telling Seeker that he and his fellow researchers plan to use an instrument called a cascade sampler to collect samples from high altitudes. The cascade sampler allows air to pass through increasingly finer impact plates designed to trap out dust and small particles, which can then be studied later.

Smith said that his team hopes to find microorganisms “persisting” and surviving, as it is rather unlikely that they are growing or dividing due to the extremely cold and arid conditions at such a high altitude. Scientists have never previously measured how long microbial lifeforms are able to remain alive in the stratosphere, he added, calling that “work that still needs to be done.”

Should they actually discover microbial life lingering, or even growing and dividing, at such high altitudes, it could have an impact on the search for life on other planets as well, including Venus. Earth and Venus similar for a period of three billion years, noted NASA astrobiologist Dr. Lynn Rothschild, a member of Smith’s team. Experts have discovered an unusual entity in the atmosphere of Venus that blocks ultraviolet light, and living organisms have not been ruled out as a possibility.

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Image credit: Thinkstock