'Eyes in the Sky': New NASA Satellite Will Watch Climate Change

Since its inception in 1958, the National Aeronautics and Space Administration (NASA) has been obsessed with exploring outer space. In the face of climate change, however, NASA’s most important mission might be its exploration of Earth.

Although it’s not as sexy as a moon landing or as historic as a manned voyage to Mars, NASA has been harvesting precious insights about Earth for decades—since at least 1968, when Apollo 8 astronaut William Anders captured his iconic “Earthrise” photo of Earth from the orbit of the moon. Shortly thereafter, in 1972, NASA launched the Earth Resources Technology Satellite (ERTS). Later known as Landsat 1, it was the first Earth-observing satellite to be launched with the express intent to study and monitor our planet’s landmasses.

Not 50 years later, Landsat 1 has a new offspring: Landsat 9, which successfully launched from California’s Vandenberg Space Force Base on Sept. 27 at 11:12 a.m. local time.

A joint effort between NASA and the U.S. Geological Survey, the decades-old Landsat mission collects satellite imagery of Earth from space, focusing on the physical material covering Earth’s surface and on changes in land usage. Scientists use that imagery to monitor everything from agricultural productivity, forest extent and health, and water quality to coral reef habitat health and glacier dynamics.

As the latest satellite in the Landsat lineage, Landsat 9 features two sensors that will measure 11 wavelengths of light reflected or radiated off Earth’s surface, including wavelengths in both the visible spectrum of light as well as other wavelengths that are invisible to human eyes. The first sensor, a camera known as the Operational Land Imager 2 (OLI-2), will capture images of the planet in visible, near-infrared, and shortwave infrared light. The second, the Thermal Infrared Sensor 2 (TIRS-2), will measure the heat radiating from the Earth’s surfaces.

Together with images from Landsat 8, which remains in orbit, that data will be a valuable input for climate scientists who are measuring, monitoring, and predicting climate change.

“NASA uses the unique assets of our own unprecedented fleet, as well as the instruments of other nations, to study our own planet and its climate systems,” NASA Administrator Bill Nelson said in a statement. “With a 50-year data bank to build on, Landsat 9 will take this historic and invaluable global program to the next level … We never stop advancing our work to understand our planet.”

Added Karen St. Germain, director of NASA’s Earth Science Division, “The Landsat mission is like no other. For nearly 50 years, Landsat satellites observed our home planet, providing an unparalleled record of how its surface has changed over timescales from days to decades. Through this partnership with USGS, we’ve been able to provide continuous and timely data for users ranging from farmers to resource managers and scientists. This data can help us understand, predict, and plan for the future in a changing climate.”

Together, Landsat 8 and Landsat 9 will collect images spanning the entire planet every eight days, giving scientists the ability to observe and track changes on the Earth’s surface with a near-weekly cadence.

“Landsat 9 will be our new eyes in the sky when it comes to observing our changing planet,” said Thomas Zurbuchen, associate administrator for science at NASA. “Working in tandem with the other Landsat satellites, as well as our European Space Agency partners who operate the Sentintel-2 satellites, we are getting a more comprehensive look at Earth than ever before. With these satellites working together in orbit, we’ll have observations of any given place on our planet every two days. This is incredibly important for tracking things like crop growth and helping decision makers monitor the overall health of Earth and its natural resources.”

Unlike Earth observations from commercial satellites, all Landsat images and their embedded data are free and publicly available—a policy that has resulted in more than 100 million downloads since its inception in 2008.

“Launches are always exciting, and today was no exception,” said Jeff Masek, NASA Landsat 9 project scientist. “But the best part for me, as a scientist, will be when the satellite starts delivering the data that people are waiting for, adding to Landsat’s legendary reputation in the data user ommunity.”