Dust Sources

Does mineral dust blown into the atmosphere cause it to warm or cool? This is the fundamental question that researchers hope a new space-based instrument will help them answer. Since much of the Earth’s desert regions are remote and inhospitable, the best way to study them may be from space. In February 2018, NASA selected the JPL-led Earth Surface Mineral Dust Source Investigation (EMIT) as an Earth Venture Instrument for development and deployment to the International Space Station. EMIT will use advanced JPL imaging spectroscopy to measure the mineral composition of the Earth’s dust source regions. This will determine the optical and chemical properties of the dust aerosols emitted into the atmosphere during high wind conditions, providing accurate boundary conditions for today’s state-of-the-art Earth system models. With accurate initialization, these models will be used to understand the global dust cycle and predict the future role of mineral dust in the Earth’s climate system.

Mineral dust impacts the atmosphere, oceans, terrestrial ecosystems, cryosphere, and inhabited lands. The EMIT instrument uses a set of technologies invented at JPL for advanced imaging spectrometer instruments and science missions, including: a three-octave, high-uniformity Dyson imaging spectrometer design; submicron adjustable detector mounts; an e-beam fabricated grating; a silicon nitride slit; and a black silicon zero-order light trap. The grating, slit, and light trap are fabricated at MDL. A prototype of the EMIT imaging spectrometer has been developed and used to advance the readiness of these key technologies. High-throughput imaging spectrometers of the EMIT type are relevant to a broad range of future NASA missions to address new science questions on the moon, Mars, and throughout the solar system. EMIT’s scheduled launch is in 2021 to proceed and address these objectives. The principal investigator for the EMIT mission at JPL is MDL’s Robert O. Green.