Bold claim: a new NASA sensor is quietly changing how we hunt for critical minerals on Earth, from lithium to a host of other elements, by scanning rocks hundreds of miles below the surface. This airborne mission pairs NASA and USGS efforts in an unprecedented, nationwide campaign that marks the largest of its kind in the United States.
AVIRIS-5, short for Airborne Visible/Infrared Imaging Spectrometer-5, is strapped into the nose of a high-altitude research aircraft and uses light to reveal the mineral makeup of rocks beneath. About the size of a microwave oven, this compact instrument reads the spectral fingerprints of minerals and other compounds in reflected sunlight. By detecting how different molecules absorb and reflect specific wavelengths, AVIRIS-5 can identify materials from rare earth elements to plant pigments, enabling geoscientists to map mineral-rich surfaces from the air.
The concept isn’t new. Imaging spectrometers have roots at NASA’s Jet Propulsion Laboratory (JPL) dating to the late 1970s, and over decades they’ve helped chart the solar system—from detailing Martian crusts to tracing lakes on Titan, and even mapping mineral-dust patterns across deserts. One instrument, the Moon Mineralogy Mapper, played a pivotal role in discovering water on the Moon in 2009, a finding that continues to guide Artemis-era resource studies. Robert Green, a senior JPL scientist, notes that these spectral datasets keep fueling missions that seek in situ resources on bodies like the Moon and beyond.
The hardware behind AVIRIS-5 shares common threads with other imaging spectrometers: mirrors, detector arrays, and electron-beam gratings that separate reflected light into its component colors, much like a prism does with sunlight.
A notable edge comes from JPL’s Microdevices Laboratory, where several cutting-edge imaging spectrometers were developed. The team combines physics, chemistry, and materials science with the fundamental properties of light. Among the materials enabling higher performance is black silicon, one of the darkest manufactured substances. When viewed under a powerful microscope, its nanoscale spike structures trap stray light, reducing interference and sharpening the spectral measurements.
Since AVIRIS first flew in 1986, four generations of the instrument have flown, tackling diverse targets—from volcanic activity to agricultural disease detection, urban debris, and wildfire monitoring. The latest, AVIRIS-5, offers spatial resolution roughly twice that of its predecessor, capable of resolving areas from under 30 centimeters up to about 10 meters across.
In the current year, AVIRIS-5 has logged over 200 hours of high-altitude flights over the Western United States as part of GEMx, the Geological Earth Mapping Experiment. These missions operate on NASA’s ER-2 aircraft from Edwards, California, and form the airborne component of USGS’s Earth Mapping Resources Initiative (Earth MRI), which aims to modernize nationwide surface and subsurface mapping.
Since 2023, the collaboration has covered more than 366,000 square miles (about 950,000 square kilometers) of the American West, a region well-suited for mineral spectroscopy due to its dry, sparse vegetation.
A key early discovery is a lithium-bearing clay called hectorite found in the tailings of an abandoned California mine, among other sites. Lithium is among roughly 50 minerals identified by USGS as critical to national security and the economy because of potential supply disruptions.
Beyond locating new mineral sources, GEMx aims to help communities realize value from older, abandoned prospects and to spot acid mine drainage risks that can occur when waste rock interacts with water and weathering processes.
Dana Chadwick, an Earth system scientist at JPL, highlights the broad potential of this technology—from land management and snowpack water resources to wildfire risk assessment—and notes that critical minerals are just the beginning for AVIRIS-5.
About GEMx
The GEMx project spans four years and is funded by USGS Earth MRI, with support from investments under the Bipartisan Infrastructure Law. The work leverages NASA’s spectroscopic imaging heritage and USGS’s data-analysis expertise to extract actionable mineral information from the collected datasets.
To learn more about GEMx, visit:
https://science.nasa.gov/mission/gemx/
