Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Decoding Mars’s Cryptic Region

20.10.2006
Mars Express's OMEGA instrument has given planetary scientists outstanding new clues to help solve the mystery of Mars's so-called 'cryptic region'.

In the 1970s, orbiter missions around Mars revealed that during southern spring, large areas near Mars's south pole became much darker than the rest of the seasonal ice cap. How could this area be in the polar region and not be covered in bright ice? Intrigued, planetary scientists called the area the 'cryptic region' of the south seasonal cap.

The mystery deepened in the late 1990s when new observations showed that the temperature of the cryptic region was close to -135º Celsius. At that temperature, carbon dioxide ice had to be present. So, scientists developed the idea that a one-metre-thick slab of clear carbon dioxide ice covered the cryptic region, allowing the dark surface underneath to be seen.

However, the new observations from Mars Express's OMEGA instrument show that this interpretation cannot be correct. OMEGA measures the amount of visible and infrared radiation bouncing off the Martian surface. In so doing, it detects minerals and ices on the surface by charting the specific wavelengths of radiation they absorb.

Carbon dioxide ice (dry ice) absorbs infrared light strongly at specific wavelengths. "We see only weak absorptions in the infrared, which would indicate little carbon dioxide ice in the cryptic region," says Yves Langevin, Institut d'Astrophysique Spatiale, Orsay, France, who led the analysis of the OMEGA results.

The only way to reconcile the apparently conflicting observations is that there is indeed a thick slab of dry ice in this area, but its surface is so heavily covered by dust that few of the Sun’s rays make it to the deeper layers and back again.

How does the dust get on top of the slab? The answer could be provided by the mysterious markings that dot the cryptic region. Known as spots, 'spiders' and 'fans' depending upon their shapes, they were discovered in 1998–1999 by NASA's Mars Global Surveyor.

Planetary scientists believe they are caused by sunlight passing through the clear ice and heating the soil underneath. This causes pressure to build up in carbon dioxide bubbles below the ice until a geyser erupts throwing dust onto the surface, creating the spots and fans. In this model, the spiders result from erosion of the underlying surface by rapid gas flows below the ice. Langevin believes that this process could significantly contribute to the dust contamination of the icy surface, which OMEGA observed.

"In terms of physics, this is a straightforward process and would go a long way towards explaining our observations," says Langevin. However, there are major questions remaining, such as why are spiders, spots and fans only observed in a small fraction of the cryptic region? And why are areas not covered by spots and fans already relatively dark.

To clarify these points, Langevin must wait until the next southern spring equinox on Mars, in 2007. During the long winter, the Sun cannot be seen from the south pole and a pristine layer of ice should build up over the cryptic region. Langevin wants to observe the cryptic region close to the spring equinox, before the Sun has touched it and started the venting process. This will tell him when the dust geysers form and whether they are the ice slab’s only source of dust contamination.

So, whilst not as cryptic as it once was, Mars's south polar region still has a few mysteries left.

Agustin Chicarro | alfa
Further information:
http://www.esa.int/SPECIALS/Mars_Express/SEMMT0O7BTE_0.html

More articles from Physics and Astronomy:

nachricht Comet or asteroid? Hubble discovers that a unique object is a binary
21.09.2017 | NASA/Goddard Space Flight Center

nachricht First users at European XFEL
21.09.2017 | European XFEL GmbH

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: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>