Key Takeaways:
- NASA’s Jet Propulsion Laboratory (JPL) is developing technology to track plastic pollution in the world’s oceans using remote-sensing technology.
- The Earth Surface Mineral Dust Source Investigation (EMIT) sensor has successfully detected plastic pollution on land and is being explored for use in detecting marine debris.
- Researchers are working to catalog the spectral signatures of marine debris to create a reference library for detection algorithms.
- The goal is to use remote-sensing technology to monitor the estimated 8 million tons of plastic that enter the ocean every year.
- NASA is collaborating with scientists and researchers to develop new technologies and train AI tools to detect marine debris.
Introduction to the Challenge
Detergent bottles and other litter can travel thousands of miles across the ocean before washing up on remote islands, highlighting the need for effective tracking and monitoring of plastic pollution. NASA’s Jet Propulsion Laboratory (JPL) is pioneering technology to address this issue, with the Earth Surface Mineral Dust Source Investigation (EMIT) sensor showing promise as a tool for tracking plastic pollution in the world’s oceans. However, scientists caution that significant challenges remain before space-based sensors can reliably detect debris at sea. The EMIT sensor, which launched to the International Space Station in 2022, relies on imaging spectroscopy to identify compounds by analyzing unique patterns in reflected sunlight.
The Technology Behind EMIT
The EMIT sensor was originally designed to map minerals across desert regions to help determine how airborne dust affects atmospheric temperatures. However, it has demonstrated remarkable versatility, capable of identifying hundreds of compounds on Earth’s surface from its orbital perch. The sensor uses imaging spectroscopy to identify compounds, which involves analyzing the unique patterns of reflected sunlight. This technology has been used in various missions throughout the solar system, including the discovery of water on the Moon in 2009. The EMIT sensor’s ability to detect plastic compounds on land has inspired marine scientists to explore its potential for monitoring marine debris.
The Challenge of Detecting Plastic in the Ocean
Detecting plastic once it enters the ocean is more challenging than detecting it on land. Seawater absorbs infrared light, masking many of plastic’s prominent spectral features. To address this challenge, researchers are working to catalog the spectral signatures of marine debris. This involves creating a reference library of molecular "fingerprints" from various types of flotsam and jetsam. The library will help detection algorithms to be developed for use with remote-sensing instruments. The reference library is essential because different kinds of debris produce slightly different spectra based on material, color, and condition.
Building a Reference Library
NASA intern Ashley Ohall led a team of collaborators in creating a newly published reference library containing nearly 25,000 molecular "fingerprints" from various types of marine debris. The open-source database compiles years of research in which scientists analyzed marine debris using handheld instruments in laboratory settings. The library includes 19 types of polymer, which is essential for detecting plastic pollution in the ocean. Standardizing these datasets into a single searchable repository is crucial for developing detection algorithms. Ohall hopes that people will see remote sensing as an important and useful tool for marine debris monitoring.
A Planet-Scale Endeavor
Most of the plastic entering the ocean originates on land, so mapping pollution concentrations near coastlines could represent a first step toward reducing what ends up on beaches and eventually washes out to sea. Carried by ocean currents, debris can travel thousands of miles from its source. A better understanding of where it is and where it’s headed could be a boon for public health and coastal tourism. Conventional methods for quantifying ocean plastic, including dragging nets through garbage patches, cannot adequately sample the millions of tons flowing through marine environments. With NASA’s support, scientists are evaluating the capabilities of existing sensors while identifying what new technologies may be needed to spot marine debris reliably.
The Future of Marine Debris Monitoring
The work being done by Ohall and other scientists brings the effort closer to leveraging powerful technologies already operating in aircraft and spacecraft. NASA’s support for this research is part of a broader effort to address the global issue of marine debris. The agency is collaborating with scientists and researchers to develop new technologies and train AI tools to detect marine debris. The goal is to use remote-sensing technology to monitor the estimated 8 million tons of plastic that enter the ocean every year. By developing effective technologies for tracking and monitoring marine debris, NASA hopes to contribute to a better understanding of the issue and inform strategies for reducing plastic pollution in the world’s oceans.