Martian Dust Storm Grows Global, Curiosity Observes Thickening Haze

A massive dust storm on Mars has expanded to engulf the entire planet, marking the first global dust event since 2007. The storm has significantly reduced sunlight at NASA's Opportunity rover, forcing it to pause scientific activities. In contrast, Curiosity, which operates on a nuclear power source, remains functional and is capturing images of the thickening haze at Gale Crater.

The atmospheric haze, measured by a parameter called 'tau,' has reached 8.0 at Gale Crater, the highest level recorded by the mission. At Opportunity, tau has surpassed 11, making accurate measurements impossible. Scientists are using Curiosity's observations, along with data from orbiting spacecraft, to better understand why some Martian dust storms grow to global scale while others remain small.

Scott D. Guzewich, an atmospheric scientist at NASA's Goddard Space Flight Center, noted that the current storm offers a unique opportunity to study these phenomena. The storm's scale is comparable to the combined area of North America and Russia, according to Guzewich. Curiosity's Mast Camera has documented the increasing haze, which is six to eight times thicker than usual for this time of year.

NASA's Jet Propulsion Laboratory has assessed the storm's impact on Curiosity and found that while the rover's cameras face challenges due to low light, the overall risk to the mission is minimal. Engineers have implemented measures to protect the rover's optics from dust accumulation. Martian dust storms are common during the southern hemisphere's spring and summer, when warming temperatures and evaporating carbon dioxide from the polar caps create conditions that lift dust into the atmosphere.