A joint mission between Nasa and the US Geological Survey (USGS), Landsat 9, which was launched on September 27, 2021, has collected its first light images of Earth.
According to a press release by Nasa, all the images, acquired on October 31 provide a preview of how the mission will help people manage vital natural resources and understand the impacts of climate change, adding to Landsat’s unparalleled data record that spans nearly 50 years of space-based Earth observation.
“Landsat 9’s first images capture critical observations about our changing planet and will advance this joint mission of Nasa and the US Geological Survey that provides critical data about Earth’s landscapes and coastlines seen from space. This program has the proven power to not only improve lives but also save lives. Nasa will continue to work with USGS to strengthen and improve accessibility to Landsat data so decision-makers in America – and around the world – better understand the devastation of the climate crisis, manage agricultural practices, preserve precious resources and respond more effectively to natural disasters,” said Nasa administrator Bill Nelson.
These first light images show Detroit, Michigan, with neighbouring Lake St. Clair, the intersection of cities and beaches along a changing Florida coastline, and images from Navajo Country in Arizona that will add to the wealth of data helping us monitor crop health and manage irrigation water. The new images also provided data about the changing landscapes of the Himalayas in High Mountain Asia and the coastal islands and shorelines of Northern Australia, said the press release.
Landsat 9 is similar in design to its predecessor, Landsat 8, which was launched in 2013 and remains in orbit, but features several improvements. The new satellite transmits data with higher radiometric resolution back down to Earth, allowing it to detect more subtle differences, especially over darker areas like water or dense forests. For example, Landsat 9 can differentiate more than 16,000 shades of a given wavelength color; Landsat 7, the satellite being replaced, detects only 256 shades. This increased sensitivity will allow Landsat users to see much more subtle changes than ever before.
“First light is a big milestone for Landsat users – it’s the first chance to really see the kind of quality that Landsat 9 provides. And they look fantastic. When we have Landsat 9 operating in coordination with Landsat 8, it’s going to be this wealth of data, allowing us to monitor changes to our home planet every eight days,” said Jeff Masek Nasa’s Landsat 9 project scientist at Goddard Space Flight Center.
The release informed that Landsat 9 carries two instruments that capture imagery: the Operational Land Imager 2 (OLI-2), which detects visible, near-infrared, and shortwave infrared light in nine wavelengths, and the Thermal Infrared Sensor 2 (TIRS-2), which detects thermal radiation in two wavelengths to measure Earth’s surface temperatures and its changes. These instruments will provide Landsat 9 users with essential information about crop health, irrigation use, water quality, wildfire severity, deforestation, glacial retreat, urban expansion, and more.
“The data and images from Landsat 9 are expanding our capability to see how Earth has changed over decades. In a changing climate, continuous and free access to Landsat data, and the other data in Nasa’s Earth-observing fleet, help data users, including city planners, farmers, and scientists, plan for the future,” said Karen St. Germain, Earth Science Division director at Nasa headquarters in Washington.
Nasa’s Landsat 9 team is conducting a 100-day check-out period that involves testing the satellite’s systems and subsystems and calibrating its instruments in preparation for handing the mission over to USGS in January. USGS will operate Landsat 9 along with Landsat 8, and together the two satellites will collect approximately 1,500 images of Earth’s surface every day, covering the globe every eight days, according to the release.
“The incredible first pictures from the Landsat 9 satellite are a glimpse into the data that will help us make science-based decisions on key issues including water use, wildfire impacts, coral reef degradation, glacier and ice-shelf retreat, and tropical deforestation. This historic moment is the culmination of our long partnership with Nasa on Landsat 9’s development, launch, and initial operations, which will better support environmental sustainability, climate change resiliency, and economic growth – all while expanding an unparalleled record of Earth’s changing landscapes,” said USGS acting director Dr David Applegate.