NASA’s mineral dust detector begins collecting data

NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) mission has provided its first view of Earth, after being installed on the exterior of the International Space Station. The milestone, dubbed “first light,” occurred on July 27 at 7:51 p.m. PDT (10:51 a.m. EDT) as the space station passed over Western Australia.

Developed by NASA’s Jet Propulsion Laboratory in Southern California, EMIT focuses on mapping Earth’s mineral dust composition. dry area To better understand how dust affects climate heating and cooling. The instrument works by measuring hundreds of wavelengths of light reflected from material on Earth. Different substances reflect differently wavelength of lightThey produce a type of spectral fingerprint that, when collected by an imaging spectrometer and analyzed by researchers, reveals what they are made of.

Ground controllers used the Canadarm2 robotic arm space Station To remove EMIT from a Dragon spacecraft and install it outside the station, a process that began on July 22 and took more than 40 hours. Engineers turned on the instrument on 24 July and cooled it to its operating temperature over the next 72 hours.

The EMIT team then collected the instrument’s first measurements, creating something called the Image Cube. The image in front of the cube shows a mix of materials in Western Australia, including exposed soil (brown), vegetation (dark green), agricultural sector (light green), a small river and clouds. The iridescent colors extending through the core of the cube are spectral fingerprints from the respective locations in the front image.

While the EMIT instrument can measure the spectral signature of light from vegetation, rocks, ice and snow, and man-made surfaces, its primary mission, starting in August, will be collecting measurements of 10 important surface minerals (hematite). calcite, dolomite, and gypsum, for example) in arid, dust-producing regions of Africa, Asia, North and South America, and Australia.

The spectral fingerprints of the dust minerals allow scientists to determine its composition. While dark, iron-rich particles strongly absorb the sun’s energy, lighter-colored clays reflect it. Right now, scientists don’t know whether mineral dust has a cumulative heating or cooling effect on the planet. Full spectral fingerprints to be collected by EMIT will help answer that question.

EMIT was developed at NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California. It was launched on July 14 from NASA’s Kennedy Space Center in Florida aboard a SpaceX Dragon resupply spacecraft carrying more than 5,800 pounds of science experiments, crew supplies and other cargo. The instrument’s data will be supplied to the NASA Land Process Distributed Active Archive Center. DAAC) for use by other researchers and the public.