Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hunt for life on Mars dealt another blow

07.01.2003


An Australian geologist has identified what could be the first ever active flow of fluids through gullies on Mars.


Map Showing location of study area


Mars Global Surveyor spacecraft image of study area.
Arrows point to dark lines that are the suspected annual flow activity along the gullies and valleys



University of Melbourne geologist, Dr Nick Hoffman, identified recent gully and channel development near the polar regions of Mars from images taken by the Mars Global Surveyor spacecraft. But contrary to the majority of scientific opinion which suggests that such features were carved by liquid water, Hoffman says the flow is most likely frozen carbon dioxide.

NASA is desperate to find signs of liquid water on Mars so they have a target for the next generation of Mars landers and rovers to go and search for life, but their search could prove fruitless if Hoffman’s analysis of the images is correct.


In the latest edition of the journal Astrobiology, Hoffman presents evidence for the flow events on Mars and demonstrates that there are substances other than water that can flow on Mars and that water is probably the least likely substance to do this. Hoffman says the channels he identified from the Surveyor images are more likely being carved by avalanches of carbon dioxide and associated debris.

"The consequences of this for life on Mars are shattering. If similar mechanisms are responsible for all the recent gullies on Mars then the near surface life NASA is so desperately searching for may not exist," says Hoffman.

"Without liquid water there cannot be life and despite recent reports of more and more ice on the Red Planet, NASA has yet to find liquid water," he says.

Many NASA scientists are doubtful about Hoffman’s observations, but at a meeting of the American Geophysical Union held last month, Hoffman says they struggled to find arguments against the evidence he presented.

The Mars Gullies were discovered in 2001. Hoffman’s analysis of the recent images shows that a patch of gullies near the South Pole shows signs of annual flow activity each Martian Spring.

"In itself the observation of active flows is a dramatic discovery since no movement has yet been seen on Mars, except for some dry dust avalanches. The gullies are thought to be the most promising candidates for liquid water flows on modern Mars and many NASA researchers are suggesting ways in which they might be formed by liquid water, but nobody has yet seen the gullies in action," says Hoffman.

Hoffman suggests NASA researchers missed these most exciting events happening in the gullies as they have been focussed on looking for liquid water in late summer.

"In the Martian Spring, when carbon dioxide frost and snow at temperatures of minus130 degrees Centigrade still fill the valleys, flow events are occurring. The flows cut through the frost at temperatures that would turn battery acid into building stone," he says.

"Nothing based on water can flow at these temperatures, so the culprit must be defrosting carbon dioxide.

"But carbon dioxide doesn’t melt on Mars; it boils directly from the solid (a process called ’sublimation’). Instead of a trickle or gush of liquid pouring down the gully, the flow appears to be a flurry of boiling dry ice avalanching down the gully. The boiling dry ice acts like a amarda of miniature hovercraft carrying a shower of sand, dust, and tumbling rocks down the slope, carving out the gullies as it goes.

**Images available: Mars photographs showing the new springtime flows, diagrams of flow models, and photos of the author are available.


More information


Dr Nick Hoffman,
School of Earth Sciences,
University of Melbourne
Telephone: 03 8344 3735 0438 397 366
Email: nhoffman@unimelb.edu.au
WWW: http://www.earthsci.unimelb.edu.au/mars/

Jason Major
Media Officer
University of Melbourne
Telephone +(61 3) 8344 0181
Mobile 0421 641 506
E-mail jmajor@unimelb.edu.au

Jason Major | EurekAlert!
Further information:
http://www.unimelb.edu.au/ExtRels/Media/03media/03jan06.html
http://www.unimelb.edu.au/news/
http://www.earthsci.unimelb.edu.au/mars/

More articles from Earth Sciences:

nachricht Seabed mining could destroy ecosystems
23.01.2018 | University of Exeter

nachricht How climate change weakens coral 'immune systems'
23.01.2018 | Ohio State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Rutgers scientists discover 'Legos of life'

23.01.2018 | Life Sciences

Seabed mining could destroy ecosystems

23.01.2018 | Earth Sciences

Transportable laser

23.01.2018 | Physics and Astronomy

VideoLinks Science & Research
Overview of more VideoLinks >>>