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Series of Storms Shrouds Mars in Dust 1
July 20, 2007
Since late June 2007, Mars has been having a series of regional dust storms. The dust raised by these individual storms has obscured most of the planet over the past few weeks. The two maps shown here are mosaics of images acquired by the Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) on two days separated by about 3 and a half weeks. The first, on 22 June, shows that there was a dust storm occurring near the east end of the Valles Marineris trough system (left of the label for "Opportunity" in the map). This was the first in the series of storms. The second mosaic shows how Mars appeared on 17 July, after dust was lofted high into the atmosphere by several regional storms and countless smaller, local dust storms.
Each map was constructed from 13 pole-to-pole image swaths at red, green, and blue wavelengths acquired by the MRO MARCI. The maps are simple cylindrical projections, with north at the top and south at the bottom. Each image swath was acquired at about 3 p.m. local time on Mars over the course of 13 orbits. The black gaps occur in the MARCI data at places where the MRO spacecraft was slewed east or west to point its instruments at a specific target of scientific interest. The north polar region is not shown because winter began on 4 July and the north polar region is in wintertime darkness. Key features labeled on the maps include the Tharsis Montes and Olympus Mons volcanoes, the Hellas impact basin, Noachis Terra, Sinus Meridiani, and the two Mars Exploration Rover (MER) landing sites, Opportunity and Spirit. The dust storms, and the planet-encircling dust veil they generated, has greatly reduced the amount of sunlight available to run the two solar-powered rovers.
Image credit: NASA/JPL/MSSS
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