Blown by wind across continents and oceans, dust does more than make skies hazy, congest lungs, and leave a film on windshields. Also known as mineral dust or desert dust, it can influence weather, hasten snowmelt, and fertilize plants on land and in the ocean. Particles from North Africa can travel thousands of miles around the globe, sparking phytoplankton blooms, seeding Amazonian rainforests with nutrients, and blanketing some American cities in a veil of grit while also absorbing and scattering sunlight.
NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) mission, set for launch in June 2022, aims to deepen researchers’ understanding of these fine particles of soil, silt, and clay from Earth’s deserts and, ultimately, how they affect climate.
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Using image spectrometer technology developed at JPL, EMIT will map the surface composition of minerals in Earth’s dust-producing regions, helping climate scientists better understand the impact of airborne dust particles in heating and cooling Earth’s atmosphere. Video credit: NASA/JPL-Caltech
Darker, iron-rich dust absorbs the Sun’s heat and warms the surrounding air, while lighter-colored particles, rich in clay, do the opposite. “Different kinds of dust have different properties – they’re acidic, they’re basic, they’re light-colored, they’re dark – that determine how the particles interact with Earth’s atmosphere, as well as its land, water, and organisms,” said Robert O. Green, EMIT’s principal investigator and a longtime researcher at NASA’s Jet Propulsion Laboratory in Southern California. With the EMIT data, he added, “we’ll be on track to map the world’s dust-source regions and understand how dust heats and cools the planet, as well as how that might change under future climat …