The Nasa-Isro Synthetic Aperture Radar (Nisar) satellite has captured a stunning outstretched wings etched into the frozen landscape.
Nicknamed “the hummingbird” by Nisar scientists, the striking formation is not a real animal but a remarkable combination of mountain, ice and radar technology revealing hidden details of Earth’s icy continent.
The image, produced in August 2025 using Nisar’s advanced L-band radar, shows Nunatak Zaterjavshijsja, a rocky mountaintop protruding through Antarctica’s vast ice sheet. As glaciers flow northeast toward the ocean, the exposed mountain acts as an obstacle, placing enormous stress on the moving ice around it.
Those stresses fracture the ice into deep cracks known as crevasses, creating a pattern that, when viewed from space, resembles the outline of a hummingbird.
What makes the erent types of ice surfaces using microwave signals rather than visible light.
Unlike conventional satellites that rely on sunlight, Nisar sends polarised microwave radar waves toward Earth and analyses how they bounce back.
Over Antarctica, the satellite transmits horizontally polarised radar signals. Depending on the surface they strike, the returning signals reveal valuable information about the structure of the ice.
Smooth, relatively uniform ice reflects the radar back with a similar horizontal polarisation. These regions appear magenta in the image. Areas containing rougher terrain, especially the vertical faces of crevasses, scatter the radar waves in multiple directions, producing vertical polarisation that is displayed in green.
This process, known as volume scattering, allows scientists to identify fractured ice and subsurface structures that would otherwise remain invisible.
The white regions indicate areas where both horizontal and vertical signals return strongly, suggesting a combination of smooth surface reflections and scattering from complex internal ice structures.
Beyond its visual appeal, the ote and rapidly changing regions on Earth.
Scientists will use such observations to study glacier movement, ice-sheet stability and the effects of climate change on Antarctica, where melting ice contributes directly to rising global sea levels.
Jointly developed by Nasa and the Indian Space Research Organisation (Isro), Nisar is the first Earth observation satellite to carry two Synthetic Aperture Radar (SAR) instruments operating at different wavelengths, Nasa’s L-band radar and Isro’s S-band radar.
The spacecraft also carries a 39-foot (12-metre) drum-shaped radar reflector, the largest radar antenna reflector ever launched by Nasa.
With its ability to see through clouds, darkness and even parts of the ice surface, Nisar is expected to transform how scientists monitor earthquakes, forests, glaciers and ecosystems wo
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