NISAR’s L-Band Radar Reveals ‘Hummingbird’ in Antarctica

The joint NASA-ISRO Synthetic Aperture Radar, or NISAR, satellite has captured a detailed image of Antarctica that scientists call the hummingbird. This radar capture reveals the Nunatak Zaterjavshijsja, a mountaintop that pushes through a flowing ice stream in East Antarctica. The structural obstruction causes significant stress in the surrounding ice, which results in deep fractures known as crevasses. These features appear as sharp green lines in the high-resolution imagery.

NISAR uses L-band radar waves to analyze the ice. The system transmits signals with horizontal polarization toward the surface. When these waves bounce back, researchers measure the orientation of the returning signals. Horizontal returns typically indicate smooth ice surfaces, rendered in magenta, while vertical returns suggest scattering from irregular areas like crevasses, displayed in green. The white areas in the image signify a combination of both scattering types.

This mission marks a major step for Earth observation. The satellite carries the largest radar antenna reflector NASA has ever launched, measuring 39 feet in diameter. By using two separate radar instruments at different wavelengths, the mission provides researchers with unprecedented data on how ice interacts with environmental obstacles.

Managed by the Jet Propulsion Laboratory, the project combines American radar technology with an Indian spacecraft bus. This recent imagery provides a precise look at how ice movement and geological formations interact in one of the most remote regions on the planet.