Co-Investigator Team, HRSC;
The parallel grooves of Phobos: new evidence on their origin from HRSC Mars Express.
Final Programme & Abstract Book: First Mars Express Science Conference 21 - 25 February 2005.
(pp. 110 - ?).
European Space Research and Technology Centre (ESTEC): Nordwijk, The Netherlands.
The origin of the grooves of Phobos has been debated since they were first discovered, and there is as yet no consensus on their origin. Early hypotheses included faults or outgassing vents caused by tidal or drag forces during the capture of Phobos, and chains of secondary craters or fracturing associated with the Stickney impact. More recently, it has been suggested that they result from chains of secondary craters from large impacts on Mars. This last hypothesis predicts that the leading apex of Phobos should be the most heavily grooved, with families of parallel grooves crossing each other at all angles, but deciding between these various hypotheses has been hampered by the fact that only about half of Phobos has been imaged by previous missions with sufficient resolution and illumination to detect the grooves. Phobos has now been imaged on 5 passes by HRSC, and on two of them, the leading apex is visible at 48m and 50m resolution. Despite unfavourable vertical illumination, it can be seen to be heavily grooved, with orientations corresponding closely to those predicted by the last idea. This is overwhelming evidence that the grooves of Phobos were caused by debris ejected from large impact craters on Mars.
|Title:||The parallel grooves of Phobos: new evidence on their origin from HRSC Mars Express|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Civil, Environmental and Geomatic Engineering
UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Space and Climate Physics
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