News / Science & Technology

Hardy Earth Microbes May Resist Conditions on Mars

MarsMars
x
Mars
Mars
Reuters
A hardy bacteria common on Earth was surprisingly adaptive to Mars-like low pressure, cold and carbon dioxide-rich atmosphere, a finding that has implications in the search for extraterrestrial life.

The bacteria, known as Serratia liquefaciens, is found in human skin, hair and lungs, as well as in fish, aquatic systems, plant leaves and roots.

"It's present in a wide range of medium-temperature ecological niches," microbiologist Andrew Schuerger, with the University of Florida, told Reuters.

Serratia liquefaciens most likely evolved at sea level, so it was surprising to find it could grow in an experiment chamber that reduced pressure down to a Mars-like 7 millibars, Schuerger said.

Sea-level atmospheric pressure on Earth is about 1,000 millibars or 1 bar.

"It was a really big surprise," Schuerger said. "We had no reason to believe it was going to be able to grow at 7 millibars. It was just included in the study because we had cultures easily on hand and these species have been recovered from spacecraft."

Contamination Risk 

In addition to concerns that hitchhiking microbes could inadvertently contaminate Mars, the study opens the door to a wider variety of life forms with the potential to evolve indigenously.

To survive, however, the microbes would need to be shielded from the harsh ultraviolet radiation that continually blasts the surface of Mars, as well as have access to a source of water, organic carbon and nitrogen.

NASA's Curiosity Mars rover is five months into a planned two-year mission to look for chemistry and environmental conditions that could have supported and preserved microbial life.

Mars' Gale CraterMars' Gale Crater
x
Mars' Gale Crater
Mars' Gale Crater
Scientists do not expect to find life at the rover's landing site - a very dry, ancient impact basin called Gale Crater located near the Martian equator. They are however hoping to learn if the planet most like Earth in the solar system has or ever had the ingredients for life  by chemically analyzing rocks and soil in layers of sediment rising from the crater's floor.

So far, efforts to find Earth microbes that could live in the harsh conditions of Mars have primarily focused on so-called extremophiles which are found only in extreme cold, dry or acidic environments on Earth.

Two extremophiles tested along with the Serratia liquefaciens and 23 other common microbes did not survive the experiment, which not only replicated Mars' low pressure, but also its cold temperature and carbon dioxide-rich atmosphere.

Follow-up Studies

A follow-up experiment on about 10,000 other microbes retrieved from boring 40 to 70 feet (12 to 21 meters) into the Siberian permafrost found six species - all members of the genus Carnobacterium - that could survive and grow in the simulated Mars chamber, located at the Space Life Sciences Laboratory adjacent to NASA's Kennedy Space Center in Florida.

The next step is to see how the microbes fare under even more hostile conditions, such as higher salt levels, more radiation and less water.

Related studies to analyze the genetics and metabolism of the common bacteria Serratia liquefaciens also are under way.

"In the search for life on another planet, we have to start with something that we at least have access to. We don't have a Martian bacterium we can experiment with, not yet, so we keep trying to see if some of our own hardy micro-organisms have the ability to grow at another location," Schuerger said.

"If we can never find a microbe that can grow under conditions on another planet, then it starts implying that life may not exist on that other location," he said.

The studies appear in the Dec. 19 edition of the Proceedings of the  National Academy of Sciences and this week in the journal Astrobiology.

You May Like

Pundits Split Over Long-Term US Role in Afghanistan

Security pact remains condition for American presence beyond 2014; deadline criticized More

US Eyes Islamic State Threat

Officials warn that IS could pose a threat to US homeland More

Video Ukraine: Captured Troops Proof of Russian Role in Separatist Fight

Moscow says Russian troops crossed into Ukrainian territory by mistake More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Scientists Unlock Mystery of Bird Flocksi
X
George Putic
August 25, 2014 4:00 PM
How can flocks of birds, schools of fish or herds of antelope suddenly change direction -- all the individuals adjusting their movement in concert, at seemingly the same time? British researchers now have some insights into this behavior, which has puzzled scientists for a long time. VOA's George Putic has more.
Video

Video Scientists Unlock Mystery of Bird Flocks

How can flocks of birds, schools of fish or herds of antelope suddenly change direction -- all the individuals adjusting their movement in concert, at seemingly the same time? British researchers now have some insights into this behavior, which has puzzled scientists for a long time. VOA's George Putic has more.
Video

Video Ukraine: Captured Troops Proof of Russian Role in Separatist Fight

Ukrainian officials say they have captured Russian soldiers on Ukrainian territory -- the latest accusation of Moscow's involvement in the conflict in eastern Ukraine. VOA's Gabe Joselow reports from the Ukrainian side of the battle, where soldiers are convinced of Russia's role.
Video

Video Rubber May Soon Come From Dandelions

Synthetic rubber has been around for more than a century, but quality tires for cars, trucks and aircraft still need up to 40 percent or more natural rubber content. As the source of natural rubber, the rubber tree, is prone to disease and can be affected by bad weather. So scientists are looking for replacements. And as VOA’s George Putic reports, they may have found one in a ubiquitous weed.
Video

Video Jewish Life in Argentina Reflected in Yiddish Tango

Jewish people from across Europe and Russia have been immigrating to Argentina for hundreds of years. They brought with them dance music that were eventually mixed with Argentine tango. The result is Yiddish tango -- a fusion of melodies and cultural experiences that is still evolving today. Elizabeth Lee reports from the Skirball Cultural Center in Los Angeles, where one band is bringing Yiddish tango to an American audience.
Video

Video Peace Returns to Ferguson as Community Tries to Heal

Thousands of people nationwide are expected to attend funeral services Monday in the U.S. Midwestern city of St. Louis, Missouri, for Michael Brown, the unarmed African-American teenager who was fatally shot by a white police officer August 9 in the St. Louis suburb of Ferguson. The shooting touched off days of violent demonstrations there, resulting in more than 100 arrests. VOA's Chris Simkins reports from Ferguson where the community is trying to move on after weeks of racial tension.
Video

Video Meeting in Minsk May Hinge on Putin Story

The presidents of Russia and Ukraine are expected to meet face-to-face Tuesday in Minsk, along with European leaders, for talks on the situation in Ukraine. Political analysts say the much welcomed dialogue could help bring an end to months of deadly clashes between pro-Russia separatists and Ukrainian forces in the country's southeast. But much depends on the actions of one man, Russian President Vladimir Putin. VOA's Daniel Schearf reports from Moscow.
Video

Video Artists Shun Russia's Profanity Law

Russia in July enacted a law threatening fines for publicly displayed profanity in media, films, literature, music and theater. The restriction, the toughest since the Soviet era, aims to protect the Russian language and culture and has been welcomed by those who say cursing is getting out of control. But many artists reject the move as a patronizing and ineffective act of censorship in line with a string of conservative morality laws. VOA's Daniel Schearf reports from Moscow.
Video

Video British Fighters on Frontline of ISIS Information War

Security services are racing to identify the Islamic State militant who beheaded U.S. journalist James Foley in Syria. The murderer spoke English on camera with a British accent. It’s estimated that several hundred British citizens are fighting for the Islamic State, also called ISIL or ISIS, alongside thousands of other foreign jihadists. Henry Ridgwell reports for VOA from the center of the investigation in London.

AppleAndroid