After being installed on the outside of the International Space Station, NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) mission provided its first view of Earth. The milestone, called “first light”, occurred at 7:51 p.m. PDT (10:51 p.m. EDT) on July 27 as the space station passed over Western Australia.
Developed by NASA’s Jet Propulsion Laboratory in Southern California, EMIT focuses on mapping the composition of Earth’s mineral dust arid regions to better understand how dust affects climate heating and cooling. The instrument works by measuring the hundreds of wavelengths of light reflected from materials on Earth. Different substances reflect different wavelengths of lightproducing a sort of spectral fingerprint which, collected by an imaging spectrometer and analyzed by researchers, reveals their composition.
Ground controllers used the Canadarm2 robotic arm of the space station to remove EMIT from a Dragon spacecraft and install it outside the station, a process that began July 22 and took more than 40 hours. Engineers powered up the instrument on July 24 and cooled it to operating temperature over the next 72 hours.
The EMIT team then collected the first measurements from the instrument, creating what is called an image cube. The image on the front of the cube shows a mix of materials in Western Australia, including exposed soil (brown), vegetation (dark green), agricultural fields (light green), a small river and clouds. The rainbow colors extending across the main part of the cube are the spectral fingerprints of the corresponding points in the frontal image.
While the EMIT instrument can measure the spectral signature of light from materials such as vegetation, rocks, snow and ice, and man-made surfaces, its primary mission, starting in August, will be to collect measurements of 10 important surface minerals (eg hematite, calcite, dolomite and gypsum) in arid and dusty regions of Africa, Asia, North and South America and Australia.
Spectral fingerprints of minerals in the dust allow scientists to determine its composition. While dark iron-rich particles strongly absorb solar energy, light clays reflect it. At this time, scientists do not know if mineral dust has a cumulative heating or cooling effect on the planet. The full spectral fingerprints collected by EMIT will help answer this question.
EMIT was developed at NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California. It launched aboard a SpaceX Dragon resupply spacecraft carrying more than 5,800 pounds of science experiments, crew supplies and other cargo from NASA’s Kennedy Space Center in Florida on July 14. Data from the instrument will be delivered to the NASA Earth Processes Distributed Active Archive Center (DAAC) for use by other researchers and the public.
Quote: NASA mineral dust detector begins collecting data (2022, July 30) retrieved July 31, 2022 from https://phys.org/news/2022-07-nasa-mineral-detector.html
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