Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars takes its cap off

07.12.2001


Mars’ ice caps are mostly frozen carbon dioxide.
© NASA


Pits in the martian ice cap expanded over the course of a year.
© M. Malin


Mars’ polar ice caps are slowly melting.

The martian ice caps are shrinking. As they are made mostly of frozen carbon dioxide, this evaporation could trigger an increase in Mars’ own greenhouse effect.

Images from the Mars Global Surveyor spacecraft show that ice ridges and escarpments have retreated over the past two years or so. The orbiting probe has also captured the ice thickening and thinning with the passing seasons.



The reason for the change is not yet clear. But it means that Mars’ climate may be changing. "These observations," say Michael Malin and co-workers at Malin Space Science Systems in San Diego, California, "suggest that the present martian environment is neither stable nor typical of the past."

Malin and his colleagues studied photos of the two ice caps taken between October 1999 and August 20011. The pictures show ridges and pits of ice, some just a few metres wide. In some places, the edges of these features seem to have retreated by up to three metres over the observation period.

In other words, the ice caps have shrunk, irrespective of seasonal changes. The researchers estimate that if all the losses are due to evaporation of carbon dioxide, the amount of this gas in the atmosphere must be increasing by about 1% every martian decade.

Mars’ atmosphere is very thin - its pressure is less than 1% of that on Earth - and consists mostly of carbon dioxide. But enough carbon dioxide evaporating from the poles would make a big difference. Because atmospheric carbon dioxide prevents solar heat radiating back into space, it warms the planet.

Ice cycle

The Mars Global Surveyor also carries a laser altimeter, an instrument that can track changes of as little as a few centimetres in the height of the ice2.

Using this device, David Smith of NASA’s Goddard Space Flight Center in Maryland and co-workers have found that ice height at both poles changes by about a metre between summer and winter. This shows that there is a considerable reservoir of carbon dioxide in the ice caps that can be pumped to and from the atmosphere.

The researchers find that the size of the north and south polar caps seem to change by about the same amount, despite the fact that, because of the shape of Mars’ orbit, the planet’s north pole is thought to get hotter than its south.

References
  1. Malin, M. C., Caplinger, M. A. & Davis, S. D. Observational evidence for an active surface reservoir of solid carbon dioxide on Mars. Science, 294, 2146 - 2148, (2001).
  2. Smith, D. E., Zuber, M. T. & Neumann, G. A. Seasonal variations of snow depth on Mars. Science, 294, 2141 - 2146, (2001).


PHILIP BALL | © Nature News Service
Further information:
http://www.nature.com/nsu/011213/011213-1.html

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>