Landsat: 50 Years Observing a Changing Earth
For a half-century, the Landsat satellites have revealed patterns of change across our crowded planet.
Since 1972, the joint USGS/NASA Landsat series of Earth-observing satellites has continuously acquired images of the Earth’s land surface, providing uninterrupted data to help land managers and policy specialists make informed decisions about natural resources and the environment.
The first Landsat satellite launched on July 23, 1972. After 50 years and seven additional launches later, Landsat continues to provide consistent and constant remotely sensed data for scientists and decision makers.
Landsat data is used by people and organizations in the United States and around the world. These data are used by government, commercial, industrial, civilian, military, and educational communities to support a wide range of applications in global change research, agriculture, forestry, geology, resources management, geography, mapping, water quality, and oceanography, just to name a few.
Join us in celebrating 50 years of the Landsat program and see dramatic changes across the Earth that are revealed via a half-century of collected images.
Five Decades of Discovery
The dream of the Landsat program was born in 1966 after astronauts’ photographs demonstrated the value of imaging the Earth from space. Today, this game changer in the field of remote sensing science is the longest running satellite program in U.S. history.
This timeline provides a snapshot of major accomplishments by the Landsat program over the past 50 years.
1972-1982
NASA launches the Earth Resources Technology Satellite, later to be renamed Landsat 1. The satellite is the first to be dedicated to observing Earth's land surface. Scientists could now see damage from wildfires or invasive insects, measure the health of vegetation, and map crop types. They could also watch for changes between each pass of the polar orbiting satellite. In 1975 Landsat 2 launched and was followed by Landsat 3 in 1978. This ensured a long-term commitment to the program.
1982-1992
Landsat 4 and 5 are launched. These satellites improved the image resolution to 30 meters allowing observers to see areas about the size of an American baseball infield. Landsat 5 holds the world record for the longest-operating Earth observation satellite. It orbited Earth more than 150,000 times over 28 years and captured the first civilian satellite observations of the 1986 Chernobyl nuclear disaster.
1992-2002
The only commercial launch of the Landsat program, Landsat 6 never achieved orbit. In 1999 Landsat 7 was launched bringing advancements in image quality in the third decade of continuous Earth observation.
2002-2012
In 2008, the U.S. Geological Survey made all Landsat data available at no cost to users. Up to this point, scientists rarely could take advantage of all Landsat data for a single location to study changes over time. The impact of the policy was transformational. Where 53 Landsat scenes had been leaving the archive every day when imagery had to be purchased, the number jumped to 5,775 daily when the price tag was removed.
2012-2022
An economic analysis of Landsat imagery determined it provided $2.06 billion in annual benefits to United States data users alone, and $3.45 billion worldwide. In September 2021, Landsat 9 was launched and replaced Landsat 7. Every eight days the satellites record the highest quality imagery available in the program’s lifetime. The first images from Landsat 9 were released in December 2021.
Changing Lands and Waters
Earth’s surface is constantly changing. Some changes—like earthquakes, volcanoes, floods, and landslides—happen suddenly. Other changes, like erosion, happen slowly over time.
This selection of Landsat images is a tiny sample of the millions of images that show how our world is changing. Let’s begin with an example showing how Landsat allows us to monitor water supplies.
Aral Sea 2000 to 2017
The Aral Sea once covered about 68,000 square kilometers, an area slightly larger than the U.S. state of West Virginia. Once the fourth largest lake in the world, it is now only about 10 percent of its size back in 1960.
The Sea has split into two separate bodies of water, now referred to as the North Aral and South Aral Seas. The North Aral has stabilized, but the South Aral has continued to shrink and become saltier.
Ethiopia 2014/2017
In Ethiopia, a series of large dams on the Omo River provides electricity for the country, with enough to export to neighboring countries. Hydropower projects of this scale often come with downsides as well—they can have a massive effect on the landscape. Reservoirs can change local ecosystems and fish habitat, and sometimes displace large populations of people.
Egypt 1997 to 2022
In the Sahara Desert in southern Egypt, center pivot irrigation fields began appearing where there had only been sand. Precipitation is extremely rare here—so how do they get water for all of these crops?
The region sits atop the Nubian Sandstone Aquifer System and water is pumped from wells to the surface and spread onto the fields via center-pivot irrigation sprinklers. The region now produces about a third of Egypt’s wheat crop.
Bolivia 1986/2021
In the 1960s, San Julian, Bolivia, was nearly inaccessible. Located deep in the Amazon Rain Forest, the few roads that existed were only passable during the dry season. Bolivia started a program to settle the area, to drive development and improve the economy. This development resulted in the deforestation of the rain forest.
Changing Cities
Landsat can help city planners identify the fastest growing parts of an area allowing them to develop long-term strategies to manage urban expansion.
Las Vegas, Nevada 1972/2021
Las Vegas, Nevada is one of the fastest growing metropolitan areas in the United States. Las Vegas grew from a population of 1,375,765 in 2000 to 1,951,269 in 2010, a 41.8% increase. These images show the rapid growth of the city. The tip of Lake Mead is visible east of the city (dark area) where the Hoover Dam impounds the Colorado River.
Dallas-Fort Worth 1974/2022
These images show the Dallas–Fort Worth metropolis in northeastern Texas. Suburbs in many American cities are characterized by sprawling growth--strip development along highways with subdivisions behind them that include houses with relatively large lots.
Dallas suburbs have grown dramatically over the last five decades, filling in and taking over land that was once farm fields. The Dallas-Fort Worth metro area has grown from a population of 2,378,000 in 1970 to 7,637,387 by 2020.
Doha, Qatar 1972-2021
Doha, the capital of Qatar, used to be a small fishing and pearl diving village. It’s now Qatar's largest city with skyscrapers and a fast-growing urban area. The majority of the country’s population lives in metropolitan Doha.
Oil was discovered in Qatar in 1937, and urbanization soon followed. Doha is expected to grow more as the Qatar government continues to build new stadiums and improved public transportation systems.
Shanghai, China 1984/2021
Shanghai, China sits on the Yangtze River delta along China’s eastern coast. In 2000, Shanghai’s population was 16.4 million people. By 2019, its population exceeded 22 million. It’s the largest city in China and 8th largest in the world. Much of Shanghai’s growth has been in suburban and outlying districts. The Landsat imagery shows smaller populated areas outside of Shanghai expanding and then being absorbed by additional urban expansion. Growth is also notable along transportation corridors. Landsat data provides insight into urban planning and sustainable development.
Changing Climate
Landsat satellites give us a global perspective on our constantly changing planet. Although some change is due to natural causes like earthquakes, other changes are the result of human-caused drivers, like greenhouse gas emissions, that lead to warming temperatures on a global scale.
Columbia Glacier, Alaska 2002-2021
Changes to Alaska’s Columbia Glacier are well documented by Landsat data over the past few decades. Since 1980, it has retreated 20 kilometers, making it one of the most rapidly receding glaciers in the world.
This series of Landsat images shows the retreat, including an acceleration of the retreat in the early 1990s, followed by slowdowns between 1994 and 2006. The false-color images use shortwave-infrared, near-infrared, and green wavelengths to highlight these changes, where snow and ice appear cyan, vegetation is green, open water is dark, and exposed bedrock is brown.
Utah/Arizona 1998-2022
Glen Canyon Dam on the Colorado River was completed in 1963. It created Lake Powell, which ebbs and flows depending on rain totals upstream. Since 2000, the Colorado River Basin has been in an extended drought. During the period 2000 - 2018, lake levels dropped to less than half capacity.
Droughts combined with a rising population means water sustainability could continue to be a challenge.
Camp Fire, California 2018
In 2018, the Camp Fire became the deadliest wildfire in California’s history. Landsat 8 captured an image of the fire just hours after it started, and intense northeasterly winds and dry fuels caused the fire to spread rapidly. The Camp Fire burned over 100,000 acres in just two days. More than 6,500 homes were destroyed, most of them in Paradise, a city of 27,000 people.
The Next 50 Years
The Landsat Program changed the world in 1972, simply by closely observing it. Because thousands of satellites now orbit and observe our planet, and satellite imagery is just a tap away on our smartphone maps, it’s easy to lose sight of just how revolutionary the Landsat idea was. Landsat 9 recently launched, ensuring that scientists and researchers will continue to use Landsat’s unparalleled archive of 10 million scenes--and counting--to explore changes over time in landscapes and ecosystems around the world, from forests to coasts to urban areas.
"Landsat is truly a system of systems. It has unique capabilities for addressing user needs. It also nicely complements some of the other available missions and systems out there." – Paul Haugen, USGS chief engineer and acting project manager for Landsat Next
Most recently, cloud computing has been revolutionizing remote sensing by allowing people to access and analyze massive amounts of data in the cloud rather than on their local computer.
Climate change affects different parts of the Earth in different ways, from rising seas, extreme droughts, and sweltering cities to intensified storms, dwindling rivers, and worsening wildfires. Satellites shift our perspective and let us look down on one location, look across a broad region, look back in time, and even look forward. They help us learn from the past and present and give us a chance to change the future.
Earth observation satellites hold a vital key to understanding our planet and preserving it for the future—and ultimately preserving humankind.
