NISAR Views Mount St. Helens
NASA/JPL-Caltech
Description
This image captured by U.S.-Indian Earth satellite NISAR on Nov. 10, 2025, shows Washington’s Mount St. Helens. The image is cropped from a much larger swath spanning the Pacific Northwest on a cloudy day; NISAR’s L-band SAR instrument is able to peer through the clouds at the surface below.
In Pacific Northwest imagery from the NASA-ISRO Synthetic Aperture Radar mission, some areas are dotted in magenta due to radar signals strongly reflecting off flat surfaces like roads and buildings, combined with the orientation of those surfaces relative to the satellite’s ground track. The yellow can be produced by a range of different factors, including land cover, moisture, and surface geometry. Yellow-green in the imagery generally indicates vegetation, such as the forests and wetlands covering the region.
Relatively smooth surfaces, including water and — as is most likely the case in this image — vegetation-free clearings on the mountaintop, appear dark blue. Near the foot of the mountain are patches of purple squares cut into the lighter green vegetation. Their precise right angles show that they’re clearly man-made; they’re likely the effect of forests being thinned or possibly vegetation growing back after having been thinned in the past.
A joint mission developed by NASA and the Indian Space Research Organisation (ISRO), NISAR launched in July 2025 from Satish Dhawan Space Centre on India’s southeastern coast. Managed by Caltech, JPL leads the U.S. component of the project and provided the satellite’s L-band SAR and antenna reflector. ISRO provided NISAR’s spacecraft bus and its S-band SAR.
The NISAR satellite is the first to carry two SAR instruments at different wavelengths and will monitor Earth’s land and ice surfaces twice every 12 days, collecting data using the spacecraft’s giant drum-shaped reflector, which measures 39 feet (12 meters) wide — the largest radar antenna reflector NASA has ever sent into space. To learn more about NISAR, visit:
To learn more about NISAR, visit:
https://science.nasa.gov/mission/nisar/
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