Earth microbe may survive on Mars

2013-01-10 07:34
Nasa's Mars rover Curiosity has tasted Martian dirt. (Nasa, JPL-Caltech, MSSS, AP)

Nasa's Mars rover Curiosity has tasted Martian dirt. (Nasa, JPL-Caltech, MSSS, AP)

Multimedia   ·   User Galleries   ·   News in Pictures Send us your pictures  ·  Send us your stories

Cape Canaveral - 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," said microbiologist Andrew Schuerger, with the University of Florida.

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 (mbar), Schuerger said.

Sea-level atmospheric pressure on Earth is about 1 000mbar or one bar.

Ultraviolet radiation

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

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.

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 analysing 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.

Hostile conditions


A follow-up experiment on about 10 000 other microbes retrieved from boring 12m to 21m 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 Centre 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 analyse 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 19 December edition of the Proceedings of the National Academy of Sciences and this week in the journal Astrobiology.
Read more on:    nasa  |  environment
NEXT ON NEWS24X
SHARE:

Read News24’s Comments Policy

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
0 comments
Add your comment
Comment 0 characters remaining
 

Inside News24

 
/News
 

Joburg hot spots for cocktails, craft beer, tapas and wine!

It’s the season to be jolly – so we’ve rounded up some new Joburg hot spots!

 
 

I love summer.24

The craziest deaths of 2014
How to make this a sensual, sexy summer!
This is what South Africans Googled in 2014!
This hilarious song is your new holiday anthem

Jobs in Cape Town [change area]

Property [change area]

Travel - Look, Book, Go!

Kalahari.com - shop online today

2DAYS ONLY – 30% off Appliances

Coffee makers, blenders, fans, juicers and more. T&Cs apply. Shop now!

2 DAYS ONLY – 40% off books

Get 40% off when you buy 2 books. For two days only! T&Cs apply. Buy now!

Up to 50% off on outdoor gear

Save on chairs, blankets, cooler bags, umbrellas and more. Shop now!

Save on Samsung

Cameras, mobile phones, TVs, Tablets and more. While stocks last. Shop now!

Grand Theft Auto 5

Now available on PS4, Xbox One and PC from R649. Buy now!

OLX Free Classifieds [change area]

Samsung Galaxy s4

Mobile, Cell Phones in South Africa, Western Cape, Cape Town. Date October 24

Best bargain in big bay

Real Estate, Houses - Apartments for Sale in South Africa, Western Cape, Cape Town. Date October 25

VW Golf 6, 1.6 Trendline (Excellent condition)

Vehicles, Cars in South Africa, Western Cape, Cape Town. Date October 25

Horoscopes
Aquarius
Aquarius

You may be emotionally defensive or reserved today. You need to step up today as there may be extra responsibilities to deal with....read more

There are new stories on the homepage. Click here to see them.
 
English
Afrikaans
isiZulu

Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Settings

Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.








Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.