An Etymological Dictionary of Astronomy and Astrophysics
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An unusual, frequently severe weather condition characterized by strong winds and dust-filled air over an extensive area. See also → dust devil, → dust whirl.

→ dust; → storm.

A violent atmospheric disturbance on Mars marked by high amounts of dust, especially during spring and summer seasons of the planet southern hemisphere. The elongated orbit of Mars has several important consequences. During southern spring and summer, Mars travels near its → perihelion, while its southern pole is tilted toward the Sun. Therefore, its surface receives much more heat . The atmosphere's temperature near surface raises and since the upper layers of the atmosphere are cold, warm air moves up and takes dust particles upward. Each several years big storms occur and cover significant portions of the planet such that dust stays in the atmosphere for several weeks or months. See also → Mars' calendar.

→ Mars; → dust; → storm.