Opportunity has close encounter with Martian dust devil
NASA's Mars Opportunityrover has captured a rare image of a Martian dust devil travelingacross the surface of the Red Planet. The rover craned back to takein the view as it scaled the southern edge of the Marathon Valley insearch of fresh minerals to mine.
Dust devils are acommon occurrence back here on Earth, and have been repeatedlyspotted by spacecraft orbiting the Red Planet. The mini twisters have also been recorded by Curiosity and Opportunity's twin roverSpirit during its tenure at Gusev Crater prior to losing contact inMar. 2010.
The devils are createdwhen heat from the Sun impacting on the Martian surface causes acolumn of warm air to rise fast enough to drag along some of the dustgrains covering the ground. While the winds thatwhip up the devils are believed to be too weak to pose a threat,being created as they are on a planet with a relatively feebleatmospheric pressure compared to that of our home planet, the detrituscarried in the maelstrom could interfere with future intrepidexplorers.
Devils have thepotential to severely reduce visibility, and in so doing heightenenvironmental dangers. Furthermore it has been theorized that fastmoving dust could become electrically charged, causing an arcingreaction with an astronaut's spacesuit and creating electromagneticinterference.
The specimen capturedby Opportunity's navigational camera (NavCam) on Mar. 31. 2016appears to be little more than a baby. Devils have been observed fromorbit reaching 12 miles (20 km) high, and have been known to clusterin groups of eight.
Anyone familiar withthe exploration of Mars, or even just the recent Ridley Scottadaptation of Andy Weir's The Martian, will know that missionsto the Red Planet are measured in sols. Opportunity is currently battling through sol 4,336, a full 4,246 solar dayspast its anticipated expiry date, and still sending back stunningimagery of the Martian landscape. How's that for engineering excellence?