The dust storm on Mars is now affecting the skies across the entire planet. Opportunity remains in low-power mode and Curiosity is now also seeing darkened skies. However, some albedo features are beginning to show again through the dust — stay tuned.
The dust storm that broke out at the end of May is now affecting the skies across the entire planet. The storm has grown in size and NASA now classifies it as a "planet -encircling" or "global" dust event, according to deputy principle investigator Bruce Cantor of the Mars Color Imager Camera on board NASA's Mars Reconnaissance Orbiter (MRO).
NASA's Opportunity rover remains in low-power mode and out of contact with mission operators as dust continues to blot out the sun at its location near Sinus Meridiani, while across the globe at Gale crater, Curiosity is experiencing a thickening haze of dust. Curiosity is powered by a radioisotope battery, so is expected to remain largely unaffected by dust. This offers scientists a rare chance to study a major dust storm from the surface of the planet, with additional observations by the fleet of orbiting spacecraft including MRO, NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, Mars Odyssey, and the ESA / NASA Mars Express orbiter.
Daily photos by Curiosity's Mast Camera show a steadily darkening sky, with current opacity estimates at six to eight times thicker than previously experienced at this time of the season in Gale Crater. Engineers at the Jet Propulsion Laboratory say the dust poses little risk for the mission besides increased exposure times for imaging due to the decreasing light levels.
The View from Earth
Observers watching the developments on Mars have a slightly different take. While the storm has blotted out many familiar albedo features and has reduced the overall contrast seen through telescopes, the thickest dust has largely been confined to the hemisphere with Syrtis Major, Sinus Meridiani, Mare Erythraeum, and Mare Acidalium.
Jeff Beish, a contributor to the Association of Lunar and Planetary Observers (ALPO), also classifies the storm as a globe-encircling event but hesitates to call it a global dust storm, particularly when compared to the storm of 1971. "We can still observe albedo markings such as Aurorae Sinus, Mare Cimmerium, Mare Sirenum, and the South Polar Cap," he states, "so calling this a global storm may be a stretch."
Parts of Syrtis Major and Sinus Meridiani (where Opportunity is waiting out the storm) have re-appeared in the past days, a sign that the dust is settling out in that region. But much like weather on Earth, the situation can change quickly; in fact, on the morning of June 22nd, a thick band of dust appeared over western Solis Lacus in images captured by French amateur Christophe Pellier. Amateurs are encouraged to continue monitoring the planet to watch for new developments.
For more on the storm and what to watch for, see Bob King's previous coverage.