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| The NISAR mission will help researchers better understand Earth’s surface changes over time, including volcanic activity like the 2009 eruption at Mount Redoubt in Alaska. |
We often take for granted the dynamic and constantly shifting nature of Earth’s surface. From earthquakes to volcanoes, landslides to shifting glaciers, much of the planet is in perpetual motion. However, a new satellite mission from NASA and the Indian Space Research Organisation (ISRO) promises to significantly enhance our understanding of these phenomena, potentially saving lives and resources during natural and human-made disasters.
The **NISAR (NASA-ISRO Synthetic Aperture Radar)** mission, slated for launch in early 2025, will continuously measure the motion of nearly all of Earth’s land and ice-covered surfaces. Orbiting the planet, the satellite will collect data twice every 12 days, providing researchers with an unprecedented, detailed view of Earth’s surface movements. According to Cathleen Jones, NISAR applications lead at NASA’s Jet Propulsion Laboratory (JPL), “This kind of regular observation allows us to look at how Earth’s surface moves across nearly the entire planet.”
Unveiling Earth’s Shifting Surface.
The NISAR satellite is equipped with two radar systems—an L-band system from JPL and an S-band system from ISRO—designed to measure surface motion with extraordinary precision, detecting changes down to fractions of an inch. The satellite’s long-wavelength radar capabilities make it capable of working day or night, even through cloud cover and dense vegetation, a feature that is particularly useful for monitoring areas like volcanic regions or fault lines obscured by foliage.
Unlike other satellites that rely on optical instruments, NISAR’s radar-based approach can penetrate through clouds, enabling it to map terrain in all conditions. The satellite will also track the movements of glaciers, ice sheets, and sea ice, while mapping changes in vegetation, all of which are crucial for climate research and disaster monitoring.
Improved Earthquake and Volcano Monitoring.
One of the most anticipated benefits of NISAR is its ability to help predict seismic activity. While the satellite cannot predict when earthquakes will occur, it can provide valuable data on where earthquakes are most likely. By measuring the gradual shifting of fault lines and identifying areas where the Earth’s crust is “locked,” NISAR can offer critical insight into regions at risk for significant seismic activity.
Mark Simons, U.S. solid Earth science lead for the mission at Caltech, notes, “The data from NISAR will help researchers understand which parts of a fault slowly move without producing earthquakes and which sections are locked together and might suddenly slip.” In regions with less seismic monitoring infrastructure, NISAR could uncover previously unknown earthquake-prone areas.
In the case of volcanic eruptions, NISAR’s regular measurements will allow scientists to detect ground deformation caused by the movement of magma below the surface, offering clues about potential eruptions before they occur.
A Lifeline for Infrastructure Protection.
NISAR’s ability to monitor subtle shifts in the Earth’s surface could also revolutionize the way we manage infrastructure. For example, the satellite’s continuous monitoring of levees, dams, and other critical structures will help authorities detect structural changes over time, reducing the need for costly and labor-intensive surveys. In the aftermath of a disaster, such as an earthquake, NISAR could quickly identify potential damage to critical infrastructure, allowing authorities to focus on inspecting only those areas that have undergone significant change.
Jones highlights the potential for the NISAR mission to revolutionize levee inspections: “Instead of going out and surveying an entire aqueduct every five years, you can target your surveys to problem areas.”
Global Impact: A Joint Mission for Earth’s Safety.
The NISAR mission represents the first major collaboration between NASA and ISRO on an Earth-observing satellite. Both agencies have worked together on the development of the satellite’s hardware, with NASA leading the U.S. component of the project and providing the L-band radar, along with other mission components. ISRO, on the other hand, is contributing the spacecraft bus, launch services, and the S-band radar.
For ISRO, the mission is especially significant in regions like the Himalayan plate boundary, an area that has experienced some of the world’s most powerful earthquakes. “NISAR will give us unprecedented information on the seismic hazards of the Himalaya,” says Sreejith K M, ISRO’s solid Earth science lead for NISAR.
A New Era in Earth Observation.
The NISAR mission is poised to change the way we monitor and understand our planet, from improving earthquake forecasting and volcano monitoring to revolutionizing infrastructure management. With its unique ability to measure Earth’s surface movements at unprecedented detail and frequency, NISAR could help mitigate the devastating effects of natural disasters and provide invaluable data for scientific research, all while offering new tools for disaster preparedness and recovery.
As NISAR’s launch approaches, scientists are eager to begin analyzing the wealth of data it will generate, paving the way for a safer and more resilient future.