In Phoenix, blowing dust obscured the mountains surrounding the city, and at least four people were injured in a pileup when two semi-trucks jackknifed in a dust storm on I-10 in southern Arizona.

NPR: Windy Spring Storm Sweeps Through Calif., Arizona

NASA's Mariner 9 and two Soviet orbiters arrived in May 1971 to find a global-wide dust storm in progress.

MSN: History littered with failed Mars probes

Miller also is reanalyzing the data to see if there are variations when sunlight was blocked by a weeks-long dust storm on Mars, with the idea being that biological systems would have acted differently to the environmental change than geologic ones.

MSN: Viking robots found life on Mars in 1976, scientists say

And the nuclear-winter hypothesis (that the smoke from fires caused by a global nuclear war would blot out the sun's rays and thus cool the earth catastrophically) owes its origin, at least in part, to observations of a planet-wide dust storm on Mars.

ECONOMIST: Comparative meteorology