Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Down That Long Dusty Trail

11.12.2003


While Mars can claim some unique features - the largest volcano and the deepest canyon in the solar system - its rocky, dusty, cold landscape has yet to yield signs of the ultimate prize: life.



Three simple words - follow the water - have become the mantra of astrobiologists studying the Red Planet because the presence of water is believed to be a prerequisite for life, either past or present.

But as scientists look for evidence of water on Mars, they are faced with an underlying dilemma: Will they know life when they see it?


“Scientists’ approach to finding life is very earth-centric,” said Kenneth Nealson, holder of the USC Wrigley Chair in Environmental Sciences. “Based on what we know about life on Earth, we set the limits for where we might look on other planets.”

In a paper published in the current edition of the journal Astrobiology, Nealson - and Bruce Jakosky of the University of Colorado - speculated that a microbe that exists in the coldest temperatures on Earth might provide clues about how a similar organism could survive beneath the Martian polar ice caps.

The microbe in question was discovered by Corien Bakersman, a postdoctoral student in Nealson’s lab, and remains the only one of its kind. It was isolated from a cryopeg - a small, salty, liquid lake found under the Siberian permafrost.

The bacteria, named Psychrobacter cryopegella, can grow at -10 Celsius and can stay alive and even keep metabolizing at an astonishing -20 Celsius While it isn’t able to replicate itself at that extreme temperature, it maintains the minimal metabolism needed to repair and maintain its cell structures.

“This organism can exist at colder temperatures than any previously discovered,” said Nealson, a professor of earth sciences and biological sciences in the USC College of Letters, Arts and Sciences.

“We know it’s possible here, so certainly it’s possible somewhere else. This bacteria expands the limits of life, so if you can find places on Mars that are minus 20 degrees centigrade, you should take a look.”

Nealson and Jakosky looked to the Martian polar regions for a habitat similar to the one in which cryopegella survives.

While temperatures at Mars’ equatorial and mid-latitudes regularly rise above -20 Celsius, it is unlikely that there is liquid water there because of its potential to be absorbed into the atmosphere, Nealson said.

But, liquid water could be found under the frozen polar caps, he added.

Climate changes on Mars, as with all of the nine planets that orbit the sun, are tied to its obliquity, or tilt of its axis with respect to its orbital plane.

Nealson and his colleagues proposed that as the Red Planet tilted - exposing more of itself to the sun at various times in its history - temperatures at the polar ice caps were warmed to minus -20 Celsius or higher.

“If the ice at the polar caps warmed to liquid water, organisms like cryopegella could have awakened and repaired any damage that might have occurred to their various cellular components,” Nealson said.

“Then, as the obliquity changed a few million years later and the planet got colder and colder, these organisms would have been the last survivors.”

But, he added, “I would never say, ‘Go and look for this bacteria.’ I would say, ‘This is a habitat that we should look at on Mars because on Earth, similar habitats have life.’”

The paper’s other contributors were USC’s Corien Bakerman and the University of Colorado’s Ruth Ley and Michael Mellon.

Usha Sutliff | USC News Service
Further information:
http://www.usc.edu/uscnews/story.php?id=9590

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

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

Speed data for the brain’s navigation system

06.12.2016 | Health and Medicine

What happens in the cell nucleus after fertilization

06.12.2016 | Life Sciences

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>