According to the American space agency, there was only one other time humans have detected a storm similar in size. It happened in 1977 when Viking I was passing by. The 2018 storm is however slightly bigger than that and definitely much bigger than the ones observed by Mariner 9 in 1971-1972 and Mars Global Surveyor in 2001.
The first Martian dust storm was recorded by French astronomer Honore Flaugergues in 1809. Adding to that the observations made since, it becomes clear that despite its allure, Mars is a very inhospitable place.
The storms are generated by large contrasts in surface temperature at different locations. Lacking any vegetation that would stop the dust from getting picked up by winds, particles the size of individual talcum powder grains rise up and can reach up to 40 miles (60 kilometers) in elevation.
Despite the severity of the current storm and its yet unknown duration, NASA is still hopeful the battered Opportunity rover might survive after all.
The solar-powered Opportunity is severely affected by the lack of sunlight, and the power levels have dropped, requiring the machine to enter minimal operations mode. It hasn’t responded to NASA’s calls, but engineers are confident the electronics and batteries can stay warm enough to function in the severe cold.
On the other side of the planet, NASA’s other rover, the Curiosity, is somewhat safer, as it doesn’t use solar power, but has a nuclear-powered battery.