Los Angeles, California – A cutting-edge NASA instrument designed initially to map minerals in deserts has found an unexpected application: detecting signs of wastewater pollution in the Pacific Ocean. In a recent study, scientists using data from the Earth Surface Mineral Dust Source Investigation, or EMIT, identified a spectral signature of sewage in ocean waters near the mouth of the Tijuana River, just south of Imperial Beach.
Built at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, EMIT orbits Earth aboard the International Space Station, where it analyzes light reflected from the surface in hundreds of color bands. That level of detail, made possible through a process known as imaging spectroscopy, allows researchers to identify specific molecules based on their unique spectral “fingerprints.”
What researchers found was a fingerprint linked to phycocyanin, a pigment found in cyanobacteria—microorganisms that can be harmful to humans and wildlife. According to scientists, the detection lines up with field-based water samples taken from the exact location. Cyanobacteria can bloom in nutrient-rich waters, including those impacted by sewage…