Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars With Ice, Shaken, Not Stirred

29.10.2007
Mars, like Earth, is a climate-fickle water planet. The main difference, of course, is that water on the frigid Red Planet is rarely liquid, preferring to spend almost all of its time traveling the world as a gas or churning up the surface as ice. That's the global picture literally and figuratively coming into much sharper focus as various Mars-orbiting cameras send back tomes of unprecedented super high-resolution imagery of ever vaster tracts of the planet's surface.

What were just a few years ago small hints about Mars' water and climate, as seen in a few "postage-stamp" high-resolution images and topography, have given way to broader theory that explains not only the features seen on the planet today, but imply a dynamic history of Martian climate change.

"When you have postage stamps, it's like studying a hair on an arm instead of the whole arm," said Mars researcher James Head III of Brown University. Head will present the latest integrated global view of Martian surface features and how they fit with Martian climate models on Sunday, 28 October 2007, at the Geological Society of America Annual Meeting in Denver.

The pictures now reveal a range of ice-made features that show a strong preference to certain latitudes, Head explains. As on Earth, latitude-dependent features can mean only one thing: latitude-dependent climate.

The signs of water ice are obvious today at Mars' poles. But as you move towards the equator, there is plenty of evidence of water ice having shaped the surface in different ways not so long ago.

Not far from either pole, for instance, widespread bumpy polygonal patterned ground suggests the contraction and expansion of icy permafrost ground — very similar to that seen in Earth's Arctic and Antarctic. Next, between 30 and 60 degrees latitude in both hemispheres, the patterned ground gives way to a pervasive pitted texture of once ice-rich dust deposits. Even closer to the equator on the flanks of Mars' equatorial volcanoes are compelling signs of large glaciers, almost exactly like those of Earth. There are also craters which seem to be filled with glacial debris and small valleys which drop precipitously into canyons — which on Earth is usually a strong indicator that a glacier once filled and widened the canyon.

As for where all the ice went, much of it was sublimed away and deposited at the poles. The ice rules the more temperate latitudes only when the tilt of Mars' spin axis is far more extreme than today — up to 45 degrees. That tilt, or obliquity, exposed the poles to a lot more sun during the course of a Martian year, according to climate models, evaporating the ice caps. That same water refroze on the surface in the then darker and colder equatorial and middle latitudes, hence all the evidence of ice and glaciers.

"It's a quest to understand the Martian water cycle," said Head describing his work.

Among the instruments used to study Mars are the Mars Global Surveyor's Laser Altimeter (MOLA) and Camera (MOC), the Mars Reconnaissance Orbiter's Context Camera (CTX) and High Resolution Imaging Science Experiment (HiRISE), and the Mars Express's High Resolution Stereo Camera (HRSC).

WHERE & WHEN
Geological Framework of the Northern Lowlands of Mars and Evidence for Extensive Amazonian Climate Change Processes
Sunday, October 28, 2007, 8:40 a.m. - 9:00 a.m.
Colorado Convention Center Room 405
[ view abstract ]
CONTACT INFORMATION
James W. Head
Professor, Geological Sciences, Brown University
Telephone: +1-401-863-2526
Email: James_Head@Brown.edu
URL: http://research.brown.edu/myresearch/James_Head
For information and assistance during the GSA Annual Meeting, 27-31 October, contact Ann Cairns in the onsite newsroom, Colorado Convention Center Room 604, +1-303-357-1056, acairns@geosociety.org . For more information on the GSA Annual Meeting visit www.geosociety.org

Ann Cairns | EurekAlert!
Further information:
http://www.geosociety.org
http://research.brown.edu/myresearch/James_Head
http://www.geosociety.org/news/pr/07-56.htm

More articles from Earth Sciences:

nachricht Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft

nachricht How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>