by The Daily Mail
“These stunning images of mist-capped volcanoes on Mars show how the northern hemisphere of the Red Planet was transformed by meteor impacts. The collisions, which took place long after volcanic activity ceased, deposited ejected material over the lower flanks of the volcanoes, Ceraunius Tholus and the smaller Uranius Tholus. Permanent and transient features are on display in the images, taken by Mars Express and just released by the European Space Agency (ESA).
The Latin word 'tholus' means a conical dome and the base of Ceraunius Tholus is 80 miles across, while the peak rises 3.4 miles above the surrounding plains. At its summit is a large caldera that measures 15.5 miles across. Ceraunius Tholus is 80 miles across and rises 3.4 miles above its surroundings. At its summit is a large caldera that measures 15.5miles across. The images were taken from data acquired during three orbits by Mars Express between 25 November, 2004 and 22 June, 2006.
The largest and deepest of these valleys is about 2.2 miles wide and 300 metres deep. It terminates inside an otherwise unrelated elongated impact crater that happens to lie between the two volcanoes, and has created a fascinating fan shape of deposits. Although the source of the fan is still being debated in scientific circles, it may have been formed when material from a lava channel or tube was washed downwards by a melting ice cap on the volcano.
Caused by an oblique impact by a meteorite, the elongated crater between the two volcanoes is called Rahe and measures 22 miles by 11.2 miles. A smaller impact crater that measures 8 miles across can be seen to the west of Uranius Tholus. This was also formed after all the volcanic activity ended and served to cover the lower flanks of the volcanoes with ejected material, with the result that only the upper regions of the original structures are now visible.”