Landsat 9

• 29 Sep 2021

Why in News

Recently, NASA has launched an earth monitoring satellite called Landsat 9 from Vandenberg Space Force Base in California. The satellite is a joint mission of NASA and the US Geological Survey (USGS).

• This satellite is referred to as NASA's' new eye in the sky’ that will help study climate change.

Key Points

• Background:
  
  • Landsat-9 is the continuation of a series of Earth-observing spacecraft stretching back almost 50 years.
  • The first Landsat satellite was launched in 1972 and since then, Landsat satellites have collected images of earth 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 forests, coral reefs, monitor water quality and melting glaciers.
• 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.
  • The instruments aboard Landsat 9 are the Operational Land Imager 2 (OLI-2) and the Thermal Infrared Sensor 2 (TIRS-2).
    
    • OLI-2: It captures sunlight reflected off Earth’s surface and studies the visible, near-infrared, and short wave infrared portions of the spectrum.
    • TIRS-2: It has a four-element refractive telescope and photosensitive detectors that capture thermal radiation and help study the Earth’s surface temperature.
  • Along with the European Union’s Sentinel-2 satellites, the Landsat Satellite will provide better estimation of the extent of climate change.

Sentinel Satellites

• It is a family of satellites developed by the European Space Agency (ESA) under the Copernicus Programme.
• The Copernicus Programme is the Earth Observation Programme managed by the ESA, launched in 1998.
  • It was named after the scientist and observer Nicolaus Copernicus. Copernicus' theory of the heliocentric (sun-centric) universe made a pioneering contribution to modern science.
• Sentinel satellites is a group of six satellites dedicated for different purposes.
  • Sentinel 1: It provides all-weather, day and night radar images.
  • Sentinel 2: It delivers high-resolution optical images for land services.
  • Sentinel 3: It delivers data on land and ocean.
  • Sentinel 4 and 5: Monitor atmosphere from geostationary and polar orbits.
  • Sentinel 6: Provides information on oceanography and climate studies.

Earth Observation Satellites of India

• Recently, India has launched EOS-01 satellite.
  
  • It is an earth observation satellite and is intended for applications in agriculture, forestry and disaster management support.
• Earth observation satellites are the satellites equipped with remote sensing technology. Earth observation is the gathering of information about Earth's physical, chemical and biological systems.
  
  • Many earth observation satellites have been employed on sun-synchronous orbit.
• Other earth observation satellites launched by ISRO include RESOURCESAT- 2, 2A, CARTOSAT-1, 2, 2A, 2B, RISAT-1 and 2, OCEANSAT-2, Megha-Tropiques, SARAL and SCATSAT-1, INSAT-3DR, 3D, etc.

Source: IE