Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Not finding life? Dig deeper.

19.11.2004


A place so barren that NASA uses it as a model for the Martian environment, Chile’s Atacama desert gets rain maybe once a decade. In 2003, scientists reported that the driest Atacama soils were sterile.



Not so, reports a team of Arizona scientists. Bleak though it may be, microbial life lurks beneath the arid surface of the Atacama’s absolute desert. "We found life, we can culture it, and we can extract and look at its DNA," said Raina Maier, a professor of soil, water and environmental science at the University of Arizona in Tucson. The work from her team contradicts last year’s widely reported study that asserted the "Mars-like soils" of the Atacama’s core were the equivalent of the "dry limit of microbial life." Maier said, "We are saying, ’What is the dry limit of life?’ We haven’t reached it yet."

The Arizona researchers will publish their findings as a letter in the Nov. 19 issue of the journal Science. Maier’s co-authors include UA researchers Kevin Drees, Julie Neilson, David Henderson and Jay Quade and U.S. Geological Survey paleoecologist Julio Betancourt. The project began not as a search for current life but rather as an attempt to peer into the past and reconstruct the history of the region’s plant communities. Betancourt and Quade, a UA professor of geosciences, have been conducting research in the Atacama for the past seven years. Some parts of the Atacama have vegetation, but the absolute desert of the Atacama’s core -- an area Betancourt describes as "just dirt and rocks" -- has none.


Nor does the area have cliffs which harbor ancient piles of vegetation, known as middens, collected and stored by long-gone rodents. Researchers use such fossil plant remains to tell what grew in a place long ago. So to figure out whether the area had ever been vegetated, Quade and Betancourt had to search the soil for biologically produced minerals such as carbonates. To rule out the possibility that such soil minerals were being produced by present-day microorganisms, the two geoscientists teamed up with UA environmental microbiologist Maier.

In October of 2002, the researchers collected sterile soil samples along a 200-kilometer (120 miles) transect that ran from an elevation of 4,500 meters (almost 15,000 feet) to sea level. Every 300 meters (about 1,000 feet) along the transect, the team dug a pit and took two soil samples from a depth of 20 to 30 centimeters (8 to 12 inches). To ensure the sample was sterile, every time he took the sample, Betancourt had to clean his hand trowel with Lysol. "When it’s still, it’s not a problem," he said. "But when the wind’s blowing at 40 miles per hour, it’s a little more complicated."

The geoscientists brought their test tubes full of desert soil back to Maier’s lab, where her team wetted the soil samples with sterile water, let them sit for 10 days, and then grew bacteria from them. "We brought ’em back alive, it turns out," Betancourt said.

Maier and her team have not yet identified the bacteria that come from the extremely arid environment of the Atacama’s core. She can say they are unusual. She said, "As a microbiologist, I am interested in how these microbial communities evolve and respond. Can we discover new microbial activities in such extreme environments? Are those activities something we can exploit?"

The team’s findings suggest that how researchers look for life on Mars may affect whether life is found on the Red Planet. The other researchers who had tested soil from the Atacama had looked for life only down to the depth of four inches. So one rule, Quade quipped, is, "Don’t just scratch the surface." Saying that Mars researchers are most likely looking for a needle in a very large haystack, Maier said, "If you aren’t very careful about your Mars protocol, you could miss life that’s there."

Peter H. Smith, the UA planetary scientist who is the principal investigator for the upcoming Phoenix mission to Mars, said, "Scientists on the Phoenix Mission suspect that there are regions on Mars, arid like the Atacama Desert in Chile, that are conducive to microbial life." He added, "We will attempt an experiment similar to Maier’s group on Mars during the summer of 2008." As for Maier and her colleagues, Betancourt said, "We’re very, very interested in life on Earth and how it functions." Maier suspects the microbes may persist in a state of suspended animation during the Atacama Desert’s multi-decadal dry spells.

So the team’s next step is to return to Chile and do experiments on-site. One option is what Maier calls "making our own rainfall event" -- adding water to the Atacama’s soils -- and seeing whether the team could then detect microbial activity.

Mari N. Jensen | EurekAlert!
Further information:
http://www.arizona.edu

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>