What : Earth Monitoring Satellite

By : NASA and the US Geological Survey (USGS)

Brief :

• The first Landsat satellite was launched in 1972 and since then, Landsat satellites have collected images of our planet and helped understand how land usage has changed over the decades.
• In 2008, it was decided that all Landsat images will be free and publicly available and the policy has helped scores of researchers, farmers, policy analysts, glaciologists, and seismologists. Landsat images have been used to study the health of Forest’s , coral reefs, monitor water quality and melting glaciers.

What is new about Landsat 9:

• The Landsat 9 joins Landsat 8 that was launched in 2013 and the satellites together will collect images of Earth’s surface. It takes 8 days to capture the whole Earth.
• Landsat 9 carries instruments similar to the other Landsat satellites, but it is the most technologically advanced satellite of its generation. It can see more colour shades with greater depths than the previous satellites, helping scientists capture more details about our ever-changing planet.
• The instruments aboard Landsat 9 are the Operational Land Imager 2 (OLI-2) and the Thermal Infrared Sensor 2 (TIRS-2). They will measure different wavelengths of light reflected off the Earth’s surface.
• OLI-2 can see the light that we can’t see too. It captures sunlight reflected off Earth’s surface and studies the visible, near-infrared, and short wave infrared portions of the spectrum.
• TIRS-2 has a four-element refractive telescope and photosensitive detectors that capture thermal radiation and help study the Earth’s surface temperature.
• As the satellite orbits, these instruments will take pictures across 185 kilometers and each pixel will represent an area of about 30 meter X 30 meter.
• Landsat 9 will provide data that can help make science-based decisions on key issues such as impacts of wildfire, coral reef degradation, the retreat of glaciers, and deforestation.

How will the satellite help monitor climate change:

• Decode the areas at risk
• During a wildfire, will capture the plumes of smoke and help study the extent of a burning.
• Help recovery experts plan sites for replanting.
• Identify water bodies affected by potentially harmful algal blooms.
• Landsat images have helped glaciologists study the melting ice sheets of the Antarctic and Arctic regions. The images can help track cracks in the glaciers, movement of glaciers, and decode how further global warming will impact them.