The standard view of Antarctica from space is monotone: white ice, blue sky, the occasional brown rock poking through. But the surface tells only part of the story. Beneath the snow, moving ice carries stresses that optical cameras cannot detect, cracks, internal layers, and flow patterns that contain clues about how the continent’s glaciers are responding to a warming climate.
A new joint mission between NASA and the Indian Space Research Organisation is now making those hidden structures visible. NISAR, the most technically ambitious Earth radar satellite ever launched, released its first detailed imagery of Antarctic ice this week, and the pictures look nothing like what a conventional camera would produce.
A hummingbird carved in crevasses
The image that has drawn the most attention shows Nunatak Zaterjavshijsja, a mountain peak in East Antarctica that rises through a stream of flowing ice. The false-color radar image renders smooth ice in magenta and fractured ice in green. Around the nunatak, deep crevasses radiate outward in patterns that NASA scientists describe as a hummingbird in flight.
The effect is produced by how ice interacts with radar waves at different polarizations. NISAR transmits horizontally polarized signals and listens for returns in both horizontal and vertical modes. Smooth, regular surfaces reflect horizontally; rough or fractured surfaces scatter signals into the vertical channel. Where the two signals are equally strong, the image shows white.
What this means in practice is that radar can see through snowpack that blinds optical instruments, revealing the internal architecture of moving ice. Seongsu Jeong, a signal analysis engineer at NASA’s Jet Propulsion Laboratory, said the technique captures “fundamentally different properties” of ice than anything visible to the human eye.
Dozens of terabytes per day
NISAR carries two radar instruments, an L-band system from NASA and an S-band system from ISRO, sharing the largest radar antenna reflector NASA has ever launched into space, spanning 12 meters (39 feet). The satellite passes over nearly all land and ice surfaces twice every 12 days, generating tens of terabytes of data per day.
The mission launched from India’s Satish Dhawan Space Centre in July 2025 and has spent its first year calibrating instruments and refining data-processing algorithms. Calibrated L-band data was made publicly available through the Alaska Satellite Facility this week, with S-band data distributed via ISRO’s Bhoonidhi portal. Earlier limited releases had produced previews, but this marks the first major public data drop.
Beyond Antarctica, NISAR has been tracking urban growth, agricultural cycles, landslides, earthquakes, and ground subsidence in cities including Mexico City. Its dual-wavelength capability is a first for a free-flying radar mission: L-band penetrates vegetation and dry snow, while S-band provides complementary information about surface roughness and vegetation structure.