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 Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute

nachricht How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Gecko adhesion technology moves closer to industrial uses

13.12.2017 | Information Technology

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure

13.12.2017 | Physics and Astronomy

Research reveals how diabetes in pregnancy affects baby's heart

13.12.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>