Dust and Dust Devil Tracks
Large portions of the martian surface are blanketed with bright reddish-ochre dust. The dust particles are typically less than 40 micrometres in size and are composed of iron oxide minerals. Data from the Thermal Emission Spectrometer (TES) on the Mars Global Surveyor spacecraft has allowed planetary scientists to estimate the amount of dust cover for broad swaths of the planet. In general, the Diacria quadrangle is extremely dusty, particularly in Arcadia Planitia and the region around the flank of Alba Mons and the Olympus Mons aureole in the southeastern portion of the quadrangle. A few large patches of relatively low dust cover occur in Amazonis Planitia and in the northwest corner of the quadrangle.
Many areas on Mars, including the Diacria quadrangle, experience the passage of giant dust devils. When a dust devil goes by it blows away the coating of dust and exposes the underlying dark surface. Dust devils have been seen from the ground and high overhead from orbit. They have even blown the dust off of the solar panels of the two Rovers on Mars, thereby greatly extending their lives. The twin Rovers were designed to last for 3 months, instead they both lasted more than six years, and one is still going. The pattern of the tracks have been shown to change every few months.
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Milankovic Crater central area, as seen by HiRISE. Click on image to see more details: dark dunes, beautiful dust devil tracks, and boulders (small bright dots).
Read more about this topic: Diacria Quadrangle
Famous quotes containing the words dust and, dust, devil and/or tracks:
“Truth has not single victories; all things are its organs,—not only dust and stones, but errors and lies.”
—Ralph Waldo Emerson (1803–1882)
“Traveling, you realize that differences are lost: each city takes to resembling all cities, places exchange their form, order, distances, a shapeless dust cloud invades the continents.”
—Italo Calvino (1923–1985)
“in your mind inwardly despise
The brittle world so full of doubleness,
With the vile flesh, and right soon arise
Out of your sleep of mortal heaviness;
Subdue the devil with grace and mekeness,”
—Stephen Hawes (1474–1528)
“The tracks of moose, more or less recent, to speak literally, covered every square rod on the sides of the mountain; and these animals are probably more numerous there now than ever before, being driven into this wilderness, from all sides, by the settlements.”
—Henry David Thoreau (1817–1862)