Landsat 9: More Than Just A Picture

By Chris Burns, NASA Goddard Space Flight Center

For more than 50 years, the Landsat program has provided the longest continuous satellite record of the Earth’s land surface from space. Landsat 9, launched in 2021, is the latest mission in this remarkable legacy – building on decades of Earth observation with improved technology, including improved radiometric resolution, improved signal-to-noise performance and polar nighttime thermal imaging. Working in tandem with Landsat 8 to map the entire planet every eight days, data from Landsat 9 is merged with the European Space Agency’s Sentinel-2 satellites to enable near-daily global observations, providing more precise and detailed observations that help scientists and communities monitor a changing planet.

VIDEO SCRIPT

It all started more than 50 years ago with an idea:
A satellite orbiting the Earth, observing the surface of our planet and collecting data day after day.
This idea gave rise to the Landsat program, a partnership between NASA and the US Geological Survey, the longest continuous recording of the Earth’s land surface from space.
The launch of Landsat 1 in 1972 was the first link in a chain of 8 satellites, each building on the previous one.
And today, Landsat 9 continues that legacy.
Since its launch in 2021, Landsat 9 has collected more scenes per day than any previous Landsat satellite mission. collects as many scenes per day as Landsats 5 and 7 combined.
Working in tandem with Landsat 8, the two now collect nearly 1,500 scenes per day, creating a complete map of the planet’s land surface every 8 days.
It’s not just about scale, it’s about Landsat’s ability to revisit the same scene multiple times per month. With this pace of acquisitions, Landsat 9 makes it possible to track seasonal changes in crops, the spread of forest fires, the consequences of storms and even rapid changes in glaciers and coastlines.
More images means more data, fueling scientific research and applications around the world.
But when it comes to Landsat 9 imagery, it’s not just about quantity, it’s also about quality.
Although the main design of Landsat 9 is almost identical to that of Landsat 8, it is capable of collecting more detailed data thanks to improved radiometric resolution – 14 bits instead of Landsat 8’s 12 bits.
Think of it like going from a box of 4,000 pencils to a box of 16,000: every nuance captured, every subtle detail sharper.
Landsat 9’s quadrupled radiometric sensitivity makes a real difference when capturing data on the planet’s brightest surfaces, like snow and ice.
Seeing more nuances of detail is powerful, but it only matters if the image itself is clear.
Landsat 9 not only refines what we can detect, but it also eliminates static, providing a stronger signal-to-noise ratio, meaning interference-free images.
It’s like trying to hear a whisper in a noisy room: Landsat 9 dampens the static so we don’t miss anything important.
And that clarity makes a difference, especially on dark surfaces like water, which can harbor harmful algal blooms that can spread quickly, threatening drinking water supplies, local wildlife and even human safety.
By spotting these blooms with greater sensitivity, Landsat 9 gives communities and scientists more reliable and actionable information to respond to.
Landsat 9 does not trigger when the sun sets: its onboard thermal sensor, TIRS, measures the heat on the surface of our planet, even in the dark.
This means we can monitor urban heat islands, volcanic hotspots and water temperatures at night.
Since 2022, the U.S. Geological Survey’s Special Request Data Program has implemented Landsat Extended Pole Acquisition, or LEAP for short, leveraging Landsat 9’s ability to see in the dark to acquire images in the polar regions year-round when the sun may set for up to six months at the poles.
With Landsat 8, satellites can detect features such as meltwater, cracks and even free water in ice in low light conditions.
The improved coverage helps scientists better monitor ice dynamics and seasonal changes in polar regions, detecting calving events, surface melting and changes in sea ice extent, even during dark months.
Landsat 9 doesn’t work alone: ​​it’s part of a global team of satellites, where collaboration between agencies and nations gives us the clearest, most coherent view of Earth yet.
NASA’s Harmonized Landsat Sentinel-2 project merges data from Landsats 8 and 9 with those from the European Space Agency’s Sentinel-2 A, B, and C satellites to form a seamless and consistent surface reflectance record.
In this “virtual constellation”, Landsat 9 brings its spectral precision and calibrated data, helping to enable global observations every 1-2 days at 30 meter resolution.
The high fidelity, radiometric stability and continuity of Landsat 9 anchor the HLS, ensuring that the merged product maintains the scientific integrity expected by Landsat users.
Landsat 9 is much more than today’s mission: it is part of the foundations of the future.
Through the Sustainable Land Imaging program, NASA and the U.S. Geological Survey aim to preserve our ability to maintain a continuous and reliable record of Earth’s land surfaces for decades to come.
This means not only flying satellites, but also building the technology, partnerships and planning necessary to keep this record unbroken.
Within the SLI, NASA’s Sustainable Land Imaging-Technology initiative is testing new instruments that could make future missions smaller, more capable, and more efficient.
Landsat 9 is NASA’s first SLI mission and plays a key role here, setting the benchmark for data quality and coverage, proving what works today and guiding the technologies of tomorrow.
Its stability and precision are the hallmark of lessons learned previously, allowing scientists to rely on records spanning decades, and its success helps guide future innovations.
For more than half a century, Landsat satellites have provided us with uninterrupted monitoring of the evolution of our planet.
In just four years, Landsat 9 has brought this vision even further into focus by capturing millions of scenes, advancing how we track water, ice and land, and strengthening the world’s longest Earth observation record.
It’s not just another satellite in orbit. This is a bridge that continues Landsat’s legacy with improved technology while laying the foundation for the future of sustainable land imaging.
Because with Landsat, every image is more than an image: it’s a calibrated digital record, providing knowledge we can use to understand, protect and sustain life on Earth.