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This Landsat 9 (Band 4, 3, 2) image captures the sighting of the Bangladesh coastline on the Bay of Bengal on February 8, 2022. Photo: Michelle A. Bouchard, using Landsat data via USGS
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The Landsat program has collected more than 10 million satellite images which shows the condition of the Earth’s surface during last 50 years. Since its first launch on July 23, 1972, seven other satellites — three of which are still operational, while one failed to orbit — have captured the extraordinary majesty of our planet, and watched its drastic changes caused by human activities.
The result of collaboration between NASA and the United States Geological Survey (USGS), the Landsat satellite captures an image path as wide as 185 kilometers above the Earth’s surface. Thanks to his presence, we can witness for free the appearance of undulating deserts, remote islands, vast urban areas, and branching rivers that resemble veins.
In addition to providing data for scientific purposes, this program inspires projects “Earth as Art” which highlights his most captivating shots. However, these images are also a reminder of how big the role humans play in influencing the Earth’s surface. Landsat has been monitoring forest fires are getting more extremeand measure storm damage. Satellite shots also show The lake is getting drier day by day, eroded coastal land and massive deforestation.
Landsat 7 and Landsat 8 images show the flooding that submerged the area around the Gulf coast of Texas, United States, after being hit by Hurricane Harvey in August 2017. Photo: NASA/USGS
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East Kazakhstan captured by Landsat 8. Photo: NASA/USGS
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Landsat 1 is relatively simple compared to its much more modern and sophisticated successor satellites. However, the spacecraft, which was retired in 1978, will always be known as the “wave of the future”.
“The satellite has definitely revolutionized the way we observe Earth over time,” said Jim Irons, a scientist with decades of the Landsat program at NASA’s Goddard Space Flight Center, when contacted with his colleague Temilola Fatoyinbo.
“Even though we now have a lot of high-resolution data that is much more amazing, we can still compare it to Landsat,” said Fatoyinbo, a scientist who studies coastal ecosystems at the Goddard Biosphere Science Laboratory, chimed in. “Only with Landsat can we compare and observe the same place on Earth over time.”
Landsat 8 captures the “Eye of the Sahara”, the phenomenon of a giant vortex that forms near the western edge of the Sahara Desert. Photo: NASA/USGS
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The conditions on Earth that Landsat 1 observes have changed a lot, and it shows in every recent satellite shot up to Landsat 9. Scientists have warned of the severe impact of human-caused climate change, which comes from emissions of greenhouse gases from burning fossil fuels. The tremendous consequences have been successfully documented in a way that has never been seen before for the last 50 years.
Irons said Landsat could be very useful in understanding the impacts of climate change in various ways, citing observations of “glacier melt, deforestation and destruction of the Amazon forest, urban growth, [serta] ecosystem changes all of which reflect climate change”.
“For me, who focuses on studying coastal areas, I see a lot of changes that have taken place,” said Fatoyinbo. “The sightings of deforestation and changes in coastal areas are equally surprising to see.”
Landsat also pays attention to how nature is increasingly being eroded by human interests. Much damage is being done around the world due to urban development and the clearing of agricultural land. It may be difficult for humans to accept these terrifying changes, but Landsat’s catalog of satellite imagery provides the ultimate argument for the actions and solutions needed to deal with anthropogenic stress.
Landsat not only provides a stunning view of the planet from space, but also exposes its fragility—and the vulnerability of its inhabitants—in a cosmic context. This program invites us to reflect on what we have done so far, and how important the Earth is to our lives.
“We are now very focused on anthropogenic effects around the world. Much time has been spent looking at the aftermath of disasters, forest fires and urban growth. But sometimes, it’s good to look back on the pictures of ‘Earth as Art’ and realize how beautiful it is to observe Earth from space,” concluded Irons. “With Landsat data, we can all imagine what it’s like to be an astronaut looking at Earth from up there.”
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