by Staff Writers
Bonn, Germany (SPX) Feb 03, 2012
Amateur astronomers who on occasion observe Mars through the eyepiece of their telescopes are quite familiar with the region of Syrtis Major; when observing conditions are good, it can be easily identified as a dark spot on Mars.
This large volcanic region just north of Mars' equator covers an area of roughly 1300 by 1500 kilometres - about half the size of Europe. The High Resolution Stereo Camera (HRSC), operated by the German Aerospace Center, on board ESA's Mars Express spacecraft imaged a 90 by 180 kilometre section of Syrtis Major at a resolution of about 19 metres per pixel during orbit 9487 on 8 June 2011.
Syrtis Major was first observed in 1659 by the Dutch mathematician, physicist and astronomer Christiaan Huygens (1629-1695), who was also the first to recognise Saturn's rings.
The pronounced dark colouring of the region allowed Huygens to determine Mars' rotation through the change in position of Syrtis Major in the course of his telescopic observations; he was thus able to, for the first time, estimate the length of the planet's day - and he did so relatively precisely, arriving at a value of 24.5 hours (in fact it is 24 hours and 37 minutes). The name Syrtis Major is derived from the Roman name for the Gulf of Sidra on the coast of Libya.
Earth and Mars soon in opposition
As a result, the distance between Earth and Mars will be 100.8 million kilometres; during opposition on 28 August 2003 they were only 55.8 million kilometres apart, their closest approach for nearly 60,000 years.
The images shown here were produced by the Department of Planetary Sciences and Remote Sensing at the Institute for Geological Sciences of the Freie Universitat Berlin, using HRSC image data systematically pre-processed by DLR. They show a section of Syrtis Major at 16 degrees north and 73 degrees east. Visible on the general image map are volcanic lava flows that flooded the older highland material, leaving mesas (flat-topped mountains) behind.
These can be easily distinguished from their surroundings due to their lighter colouring. The flow fronts of the individual solidified lava flows resemble lobe-shaped lines with some irregularities; in the anaglyph image they are revealed as subtle height differences.
Low-viscosity lava flooded the old Mars highlands
Finally, the landscape was shaped by the force of the wind. Here the prevalent wind direction, at least in the more recent past, from east-southeast can be derived by means of the lighter aeolian deposits to the sides of the smaller impact craters sheltered from the wind.
The largest impact crater in the area shown here has a diameter of about 20 kilometres with a small mountain at its centre. West of this central mountain (above it in the image) is a small, dark field of dunes. In particular, the dunes at the front here nearly mimick the 'perfect shape' of typical sickle-shaped dunes, or barchans, common in deserts on Earth.
Another noticeable feature is that the older impact craters are found in the old highlands (in the upper half of the perpendicular views). In contrast, only smaller impact craters can be found on the younger volcanic surface in the lower half of the image. Dating by means of the crater size-frequency distribution reveals that the surface is of Hesperian age: in Mars' geological history this period, characterised by widespread volcanic activity, corresponds to about 3.7 to 3 billion years ago.
Image processing and the HRSC experiment on Mars Express
The black-and-white image is based on data acquired by the nadir channel, which has the highest resolution of all the channels. The colour-coded plan view is based on a digital terrain model of the region, from which the topography of the landscape can be derived.
The HRSC camera experiment on the European Space Agency's Mars Express mission is headed by Principal Investigator (PI) Professor Gerhard Neukum (Freie Universitat Berlin), who was also responsible for the technical design of the camera.
The science team consists of 40 co-investigators from 33 institutions in ten nations. The camera was developed at DLR under the leadership of the PI and it was built in cooperation with industrial partners EADS Astrium, LEWICKI microelectronic GmbH and Jena-Optronik GmbH.
The instrument is operated by the DLR Institute of Planetary Research in Berlin-Adlershof, through ESA/ESOC. The systematic processing of the HRSC image data is carried out at DLR. The images shown here were created by PI-group at the Institute of Geological Sciences of the Freie Universitat Berlin.
German Aerospace Center
Mars News and Information at MarsDaily.com
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Russia blames 'cosmic rays' for Mars probe failure
Moscow (AFP) Jan 31, 2012
Russia on Tuesday blamed a computer malfunction caused by the impact of cosmic rays for the failure of its Phobos-Grunt mission to Mars, one of a litany of setbacks for its embattled space programme. Announcing the initial results of the investigation into the Mars mission, Russian space agency Roscosmos also revealed the next manned launch to the International Space Station would be delayed ... read more
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