From Sanford Underground Research Facility: “NASA Exobiology studies extremophiles at Sanford Lab”

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From Sanford Underground Research Facility

June 17, 2019
Erin Broberg

Researchers with NASA’s Exobiology Program are in search of extremophiles deep below the earth’s surface.

Brittany Kruger and Lily Momper, researchers with NASA’s Exobiology Program, collect samples on the 2000 Level of Sanford Lab. Matthew Kapust

It’s not all cleanrooms and Tyvek suits at Sanford Underground Research Facility (Sanford Lab). Sometimes, it’s muck boots and headlamps. Last week, visiting biologists stepped off the cage onto the 1700 Level of Sanford Lab. From there, the team motored via trolley through the drift, took ATVs down a ramp and walked a mile through shin-deep water by the light of their headlamps to reach a collection site on the 2000 Level.

Researchers were in search of inhabitants that live deep below the earth’s surface.

The project is part of NASA Astrobiology’s Exobiology program, which aims to understand the origin, evolution, distribution and future of life in the Universe. In an earlier phase of the project, Kruger’s team collected samples from other extreme environments, including wells near Death Valley, naturally-occurring springs in Northern California and deep ocean environments.

“We are studying subsurface samples to learn how microbes are metabolizing and surviving in those locations to help us understand how life might be functioning on other planets that experience the same or similar stressors, like extreme heat, temperature, pressure, radiation and lack of sunlight,” said Brittany Kruger, field work coordinator and assistant research scientist with the DRI.

Sanford Lab, with over 370 miles of shafts, drifts and ramps, serves the project as DeMMO, or the Deep Mine Microbial Observatory. The observatory is a network of boreholes that intersect fluid-filled fractures on the 800, 2000, 3950 and 4850 levels. Kruger’s team visits two to three times a year to collect samples from the various boreholes.

“Each borehole we visit is very different in terms of microbiology,” said Kruger. “The differences are not only dependent upon depth, but also on the chemistry of the water that flows through the site.”

Once Kruger and her team collect the samples, they spend hours processing them.

“At each DeMMO borehole, we do a suite of both biological and chemical analyses sample collecting,” said Kruger. Some chemical analyses are completed in situ, while other samples are collected in bottles with preservative to be analyzed in a lab. The chemical analysis helps researchers understand the specific environment in which the microbes are living.

“In terms of microbiology, we take a two-part approach,” Kruger explained. “We take raw water back to the lab to try to grow microbes from that water sample. We also filter the water to collect and concentrate cells.” By concentrating the cells, researchers can do a roll call via DNA analysis to understand which species are present and how the community is functioning.

“With each sample, we are finding thousands of species. The vast majority overlap with samples we or others have collected elsewhere. That being said, every time we take a sample, we find many organisms that are completely undescribed in the science community and are only known by their DNA sequences. We don’t yet know what they do, how they eat or how they live.”

By studying these organisms, researchers hope to better understand how these microbes live in such extreme environments.

“There are components of each of the sites that can relate to environments in space,” explained Kruger. “For example, if we are able to sample the water coming out of the holes anaerobically, without letting oxygen influence them, then that’s much more representative of something you might find on Europa (a moon of Jupiter) or an icy world where there is plenty of water, but no oxygen.”

With the initial phase of determining whether the underground environments are stable—both microbially and chemically—the team is diving into more technically driven scientific questions, with implications for life on earth, as well as potential life in space.

“This research informs big-picture questions,” said Kruger. “As a whole, we are gaining a better understanding of subsurface microbiology.”

Learn more about DeMMO at Sanford Lab.

See the full article here .

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About us.
The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.

LBNL LZ project at SURF, Lead, SD, USA, will replace LUX at SURF

In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
“LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

FNAL LBNE/DUNE from FNAL to SURF, Lead, South Dakota, USA


U Washington Majorana Demonstrator Experiment at SURF

The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

LBNL LZ project at SURF, Lead, SD, USA


CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”