As of July 20, the public can access data from the two powerful radar instruments aboard the NISAR (NASA-ISRO Synthetic Aperture Radar) satellite. Teams in the United States and India will release files processed from the satellite’s L-band and S-band radars on an ongoing basis, helping researchers and other users track the movement of Earth’s land and ice masses, monitor changes in ecosystems like forests and wetlands, and respond to natural hazards such as landslides and earthquakes.
The release comes as NASA and ISRO (Indian Space Research Organisation) prepare to celebrate the first anniversary of NISAR’s July 30, 2025, launch from India’s Satish Dhawan Space Centre. Since that time, the mission engineering and science teams have been busy calibrating instrumentation, refining algorithms, and monitoring nearly all the planet’s land- and ice-covered surfaces twice every 12 days. Along the way, the team has captured scenes from around the globe — urban street grids, agricultural fields, landslides, earthquakes, and sinking land in Mexico City.
An early image released Tuesday revealed the fractured, barren surface of an Antarctic landscape in stark detail. In a merging of science and serendipity, it also resembles something else entirely: a hummingbird.
Despite its otherworldly quality, the Antarctic image shows a very real geographical feature called Nunatak Zaterjavshijsja, a mountaintop in East Antarctica, poking out amid a stream of ice flowing northeast to the ocean. As the moving glacier passes the obstruction, the mountain’s topography causes stresses in the ice, heavily fracturing the surrounding surfaces with deep cracks, called crevasses, which show as sharp green lines in the image.
“First, it’s a beautiful image, with rich details of features that provide insights to how the glacier is moving. Then, because radar can often see through snow and deep into the ice, NISAR can observe fundamentally different properties of Antarctic ice than can be seen in optical imagery,” said Seongsu Jeong, the signal analysis engineer who produced the image at NASA’s Jet Propulsion Laboratory in Southern California. “With NISAR we’re seeing what’s hidden beneath the surface.”
Story in magenta, green
Generated with measurements that NISAR’s L-band instrument gathered in August 2025, as U.S. and Indian mission teams tested the satellite’s systems, the “hummingbird” exemplifies one of the young mission’s hallmarks: intricately detailed imagery that is both informative and eye-catching.
The colors show differences in the way polarized microwave signals, which vibrate in different directions, interact with and reflect from the ice. Over Antarctica, NISAR transmits radar waves toward Earth with a horizontal polarization. The orientation of the signals that return — either horizontal, vertical, or both — provide clues about the object or surface that reflected them.
Signals that come back with a horizontal polarization likely bounced off a more regular surface, such as smooth ice. Those signals appear magenta in the image. Signals that return with vertical polarization may have refracted as they partially penetrated the snow and ice or scattered at different angles as they reflected off irregular surfaces, such as the faces of crevasses. Called volume scattering, these observations are displayed in green.
The white represents areas in which magenta and green signals scatter back strongly, a possible indication that there is an equal blend of surface and volume scattering.
The same scene viewed in optical light is almost entirely white with ice and snow. Slight shadows and rippling indicate the presence of the mountaintop, and textures in the surrounding area suggest the ice is not completely smooth.