Landsat is the name of a series of Earth-observing satellites, nine of them so far, that have been photographing the land surface of our planet for over half a century. The first launched on 23 July 1972. Landsats 8 and 9 are working today, flying in tandem, mapping every dry patch of Earth every eight days. Together they add roughly 1,500 new scenes to the archive every single day.
What makes Landsat different from your phone or a weather satellite is that it does not just take pictures. It takes calibrated scientific measurements. Every pixel covers a precise 30 metres by 30 metres of ground, recorded in wavelengths the human eye cannot see, with the same instruments and reference points across decades. An image from 1985 can be compared directly with an image from 2026, and the difference is real.
A Trip Through Time with Landsat 9. NASA Goddard. A decade-by-decade tour of what the archive holds.
What it actually does
A Landsat satellite carries a camera that sees in four kinds of light at once: visible, near-infrared, shortwave-infrared, and thermal. By combining these, scientists can read things our eyes cannot: how healthy a forest is, how deep a river runs, the chemistry of a glacier's ice, the surface temperature of a city in summer. The pictures often look painted in colours that do not quite exist, because they are showing real measurements in colours we can perceive.
Every 30-metre pixel is calibrated. Not approximated. That means a farmer measuring crop stress in 2026 can compare their fields directly with the same fields in 1986, and a glaciologist can quantify ice loss to the metre.
Landsat 9 at Work. NASA Goddard. What the data actually measures and why it matters.
Why it matters
In 2023, the value of Landsat data to the United States economy alone was estimated at $25.6 billion. That figure spans agriculture, flood insurance, disaster response, water management, mineral exploration, and wildfire mapping. The satellite itself cost a fraction of that to build.
In 2008, NASA and the USGS made the entire archive free to the public. Before then, a single image cost hundreds of dollars. The decision triggered the largest single increase in usage and scientific citations in the programme's history. Today the archive is used by farmers, city planners, NGOs, climate scientists, oil and gas operators, fishery managers, and the U.S. military, and is open to anyone with an internet connection.
More Than Just a Picture. NASA Goddard. 90 seconds on why a Landsat image is a scientific document.
The satellites
Nine Landsat missions have flown since 1972. Landsat 1 was the proof of concept. Landsat 5, launched in 1984, holds the world record for the longest-operating Earth observation satellite, working for 28 years. Landsat 7 launched in 1999 and is still in orbit. Landsat 8 launched in 2013 and Landsat 9 in 2021. The two are flown together, eight days apart, to give the planet a fresh look every week.
The programme is a joint effort between NASA, which builds and launches the satellites, and the U.S. Geological Survey, which operates them in orbit and manages the archive on the ground.
Cosmic Cycles 3, Earth as Art. NASA Goddard, 2023. A short film of Landsat imagery set to an orchestral score.
Imagery and data: NASA and the U.S. Geological Survey, Landsat programme, public domain. Skylit Studio is not affiliated with or endorsed by NASA or USGS.
