What is NASA's EMIT?

The Earth Surface Mineral Dust Source Investigation (EMIT) is a space instrument developed at NASA’s jet propulsion center and was launched into space on July 14, 2022. EMIT was launched using Elon Musk’s Space X rocket to its destination on the International Space Station (ISS), 400km high. The EMIT instrument circles the earth every 90 minutes from its attached position on the ISS.

Earth Surface Mineral Dust Source Investigation team created this instrument, which comprises innovators in earth system modeling, mineral dust aerosols, geology surface science, and spectroscopy imaging.

NASA’s EMIT mission’s main objective is to deliver a new efficient, and better assessment of the heating and cooling effects of mineral dust around the earth’s atmosphere and to offer predictions on the future climatic conditions that may result due to the variations of amount and type of mineral dust emitted in the atmosphere.

The EMIT instrument is an imaging spectrometer that determines the light present in visible and infrared wavelengths. Sunlight reflected from the minerals on the earth’s surface is mapped onto a detector by a telescope and spectrometer system. The detector on the EMIT instrument works by displaying different spectral signatures when various light wavelengths are distributed across its detector. The detector thereby indicates the mineral composition of the particular earth’s surface. EMIT is fast enough to compute up to 100,000 spectra per second and determine the location and composition of different minerals on the earth’s surface.

The EMIT instrument is highly sophisticated and incorporates several advanced technologies. It has a Dyson spectrometer with an extremely high optical layout, producing a high proton throughput. This means that light reaching the spectrometer detector is maximized at the highest wavelengths.

The detector has very advanced arrays which use custom-updated coatings to ensure maximum sensitivity along the range of the spectrometer wavelength. The EMIT instrument has a wide field of view (72km), meaning it has a uniform and timely spectral response and feedback. This is made sure with the use of the most advanced data processing and analysis algorithms.

Strong winds blowing over the Earth’s desert and plain lands lift dust filled with minerals, and these light particles travel great distances. Mineral dust can affect the earth’s environment in various ways since its contents differ in color and composition. Dark particles absorb sunlight energy and increase the heat on our planet, while light-colored particles reflect sunlight energy causing a cooling effect.

For example, in 2020, strong winds in Africa blew the mineral dust on the surface into the atmosphere. They then crossed over to the Atlantic Ocean, affecting the climatic conditions of the states of Florida and Texas.

Iron-containing minerals are primarily dark, while those containing clay are brightly colored. Scientists need to know the dust composition as it blows around the planet and learns how dust affects the environment’s temperature.

EMIT has also proven to be one of the best space instruments at detecting large amounts of greenhouse gases like methane and carbon dioxide. EMIT is accredited to have identified more than 50 sites on the planet with heavy methane emitters. A recent study by NASA shows that EMIT detected some of the most significant amounts of methane gas ever observed from space. A case in point is the newly imaged gas infrastructure in Turkmenistan, which released a 32km stretch of methane gas. An analysis done by scientists at NASA concluded that Turkmenistan plumes released about 51,000 kg per hour of methane gas into the atmosphere.

Two heavy emitters of methane gas observed using the EMIT instrument include an oil field in the Gulf region of New Mexico and a waste processing plant in Iran. Together, they released about 29,000 kg per hour of methane into the atmosphere. None of the mentioned case studies were previously known to NASA scientists but were discovered recently through the EMIT instrument. EMIT is very helpful in discovering new sites for greenhouse gas emissions which no one thought to look for before, and eventually discovering new oil plumes.

Methane gas accounts for nearly 30% of the rise in temperatures. Methane is a by-product of the decomposition of organic matter and a significant ingredient of natural gas used in power sites and gas facilities. Methane gas has 80% more heat-trapping ability than its close compatriot carbon dioxide. Methane gas lingers in the atmosphere for about a decade compared to carbon dioxide, which stays in the atmosphere for 90 to 100 years. This implies that reducing human activities associated with methane gas emissions immediately affects our planet’s warming.