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 Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun
18.04.2019 | University of Warwick

nachricht In vivo super-resolution photoacoustic computed tomography by localization of single dyed droplets
18.04.2019 | Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences

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: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

Im Focus: Researchers 3D print metamaterials with novel optical properties

Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna

A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

New automated biological-sample analysis systems to accelerate disease detection

18.04.2019 | Life Sciences

Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

18.04.2019 | Physics and Astronomy

New eDNA technology used to quickly assess coral reefs

18.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>