Miércoles 19 de Julio de 2006, Ip nº 162

Chaotic Martian landscape revealed in new images
Por Kelly Young

Chaotic sloped mesas dominate the aptly named Iani Chaos region of Mars, as shown in newly released images taken by the High Resolution Stereo Camera aboard the European Space Agency's Mars Express spacecraft.

This jumbled-looking region also happens to be one of 33 areas under consideration as a landing site for NASA's next big rover, the Mars Science Laboratory. The candidate landing site is actually slightly east of the image shown, which was captured on 14 October 2004.

Timothy Glotch, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, US, proposed this as a landing spot because of its similarity to Meridiani Planum, where the Opportunity rover is currently roaming. Both sites appear to be rich in haematite and sulphates. These can indicate the former presence of water, and hence possibly life.

Based on the number of meteorite impact craters, scientists believe that the disordered terrain of Iani Chaos was formed between 800 million and 1 billion years after the haematite-rich region of Meridiani Planum.

"Scary looking"
A similar process may have deposited the haematite in both regions over a long period of time. Some experts suggest the process could be a result of groundwater that rose to the surface and created pools in which sulphate was deposited. The haematite may have come later when groundwater interacted with sulphate-rich beds. Others have argued that erupting volcanoes or impacts from meteorites could have left the deposits.

The canyons at Iani Chaos are believed to have formed when subsurface water or ice erupted to the surface and the land above the newly hollowed out areas collapsed, leaving mesas.

"It looks scary," Glotch says of the chaotic terrain. The fissures can be hundreds of metres deep, which could easily prove fatal for a rover. But he believes he can find some large smooth landing spots within the chaotic landscape. The rover's target landing area is 20 kilometres across.

The proposed Iani Chaos landing site received a medium priority after the first landing site workshop for Mars Science Laboratory. The second landing site workshop is slated for 2007, when some sites will be voted out.

  19/07/2006. New Scientist Magazine.