NASA-ISRO’s NISAR satellite captures first image of Earth’s surface, revealing Mount Desert island

NASA-ISRO Radar Satellite Captures First Image of Mount Desert Island (Image: NASA)

Scientists have received the initial high-resolution radar image from a new Earth-monitoring satellite by NASA and ISRO, which will change the way we monitor land, water, and climate change.

What did the first radar image of NISAR record?

The NASA-ISRO Synthetic Aperture Radar (NISAR) mission jointly released a radar picture of Mount Desert Island, off the coast of Maine, taken on 21 August 2025. The picture, recorded by the satellite's L-band synthetic aperture radar instrument, presents water in dark color, forests in green, and hard surfaces like soil and buildings in magenta. Bar Harbor is the bright magenta-colored area on the island's northeast. This photograph was acquired during the commissioning phase of the satellite, an important phase when its sensors are bench-tested prior to starting full science operations.

How is the NISAR satellite different?

NISAR is the first mission where both L-band and S-band radar systems are used on one platform. The 25-centimetre-wavelength L-band radar is able to penetrate forest cover to detect soil moisture and monitor tiny ground movements, even fractions of an inch. This enables researchers to observe how land behaves prior to and following natural phenomena like earthquakes, volcanic eruptions, and landslides. ISRO's Space Applications Centre designed the S-band radar, which has a shorter 10-centimetre wavelength. It is very sensitive to smaller vegetation and thus suitable to monitor agricultural fields and grassland ecosystems.

When will NISAR start science operations?

The satellite was launched on July 30, 2025, at the Satish Dhawan Space Centre in India and will start its science operations in November. Once operational, NISAR will make routine, high-resolution measurements of Earth's surface, monitoring glacier, sea ice, wetland, and forest changes. The satellite will assist scientists in measuring the movement and deformation of the planet's crust due to earthquakes and volcanism.

How will NISAR help with disaster response and climate studies?

NISAR's high-speed global imaging will provide useful assistance in natural disasters by enabling before-and-after data to help one analyze damage in a short while. Its observations will help one comprehend long-term dynamics of Earth's systems, such as climate change-induced changes in ecosystems and ice dynamics. With its state-of-the-art imaging capability, NISAR is likely to be instrumental in enhancing disaster preparedness, management of resources, and environmental studies worldwide.

The first radar image from the mission represents an important milestone towards gaining fresh insights into how the surface of Earth changes and reacts to natural and human-induced alterations.