Landsat: 5 decades of images and data

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Orbital view of the volcanic smoke pillar, with its black shadow, white smoke and a dark lava flow.
Lava burns a path through La Palma, Canary Islands, Spain on September 26, 2021. This image and the next 2 below are Landsat images. The eye of Landsat from the sky is a witness to history on Earth. La Palma volcano erupted on September 19, 2021. The wall of molten rock rose up to about 40 feet (12 meters) in some places, covered 500 acres (200 hectares) of land, and destroyed more than 500 structures. Lava finally burned a path to the sea on September 29. Image via Landsat / NASA.

Landsat legacy

The latest in NASA’s series of Landsat satellites – Landsat 9 – launched this week, September 27. It will continue what is now a 50-year record of Landsat imagery and data, showing Earth changes, acquired from Earth’s orbit. So far, there are 9 million space images of the landscapes and coastlines of our home planet in the Landsat series. All are free for scientists to analyze and understand. Landsat is NASA’s advanced series of satellites. At altitude since 1972, these satellites have provided the oldest continuous recording of what is happening on Earth.

The Landsat series began on July 23, 1972, when NASA and the US Geological Survey (USGS) launched the Earth Resources Technology (ERTS-1) satellite into orbit. They later renamed it Landsat 1. It was the first Earth observation satellite launched with the idea of ​​monitoring the Earth’s surface.

Since then, there has always been at least one Landsat satellite in orbit, facing the Earth. These satellites continuously and consistently collect global images. They have created a historical archive unmatched in quality, detail, coverage and length. The images allow researchers to monitor important trends such as agricultural productivity, forest extent and health, water quality, healthy coral reef habitat, and glacier dynamics. They show the spread of humanity. After all, there are more than twice as many people on Earth today as there were when the Landsat program began in 1972. Historically, the goal of Landsat has been to empower land managers and decision makers with the tools to make sound decisions about the Earth’s resources.

In December 2020, speaking to Alok Patel of PBS’s NOVA Now podcast, NASA project scientist Jeff Masek said:

When you grow up in an area you don’t really notice the changes that take place over the years and decades. But when you time-lapse the movie, we suddenly see all of these changes: urbanization and changes in the management of forests, areas where agricultural irrigation suddenly enters desert environments.

Orbital view of smoke in white tufts and swirls with labeled cities and fires.
Fire encroaching on giant redwoods in California, September 15, 2021. The KNP complex fire in Sequoia & Kings Canyon National Parks was estimated on September 29, 2021 to have burned approximately 50,000 acres (202 square km) and be about 11% content. To the south, the Windy Fire in the Sequoia National Forest had burned nearly 90,000 acres as of September 29, with a 25% containment. Learn more about the fires via the Fresno Bee. Image via Landsat / NASA.

The launch of Landsat 9

The latest satellite in the Landsat series, Landsat 9, was launched this week on Monday, September 27, 2021. It is the ninth in the Landsat program and will work in tandem with Landsat 8 to collect images, capable of covering the entire planet every eight days. . The satellite duo will help track urban sprawl, forest cover and retreating glaciers, among other features and phenomena. Technology is advancing and Landsat 9 is therefore equipped with two unique instruments that are supposed to provide better imagery than ever before.

The Operational Land Imager 2, or OLI-2, has an image band 115 miles (185 km) wide with sufficient resolution to distinguish land cover features such as urban centers, farms, and forests. Each pixel in these images represents an area approximately 98 feet (30 m) in diameter. At this resolution, single-family homes are indistinguishable, but researchers can see large man-made objects such as freeways.

The second instrument is the thermal infrared sensor 2, also known as the TIRS-2. It will measure the temperature of the earth’s surface in two thermal infrared bands, using the principles of quantum physics to measure infrared energy emissions.

Orbital view with green ground and white clouds, an aquatic ring traces oil on a deep blue-green sea.
Hurricane Ida left an oil trail on September 3, 2021. NASA said, “Hurricane Ida left a long trail of damaged homes, infrastructure and lives from Louisiana to New England. It also left a stain on the sea. Two weeks after the storm, several federal and state agencies and some private companies are working to find and contain the oil spills in the Gulf of Mexico. Image via Landsat / NASA.

Using Landsat

NASA was responsible for the construction and launch of Landsat 9, although the US Geological Survey (USGS) will operate the satellite and process its data. All Landsat images and embedded data are free and publicly available. It has generated over 100 million downloads since its release in 2008.

Thomas Zurbuchen, associate administrator for science at NASA, said in a statement:

Landsat 9 will be our new eyes in the sky when it comes to observing our changing planet. By working in tandem with the other Landsat satellites, as well as with our European Space Agency partners who operate the Sentinel-2 satellites, we get a more complete view of Earth than ever before. With these satellites working together in orbit, we will have observations from anywhere on our planet every other day. This is extremely important for tracking things like crop growth and helping policymakers monitor the overall health of the Earth and its natural resources.

Watch this video for a Landsat road trip through time.

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Conclusion: The Landsat program provides the longest continuous spatial recording of the Earth in existence. Every day, Landsat satellites provide essential information to help land managers and decision makers make informed decisions about our resources and environment.

Source: NASA

Via Space.com

Lia De La Cruz

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About the Author:

Lia De La Cruz is a physics graduate and Editorial Assistant for EarthSky, also contributing as a field correspondent with a long-standing passion for space exploration that began early in her academic career. She launched her SkyFeed blog in 2018, which was mentioned in Feedspot’s Top 50 Space Blogs to Follow, published in Smore magazine and led her to launch a career in communications alongside her planetary passion. She currently resides in the South. California with her husband and her little pug.

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