Astronomy

Astronomy? Find a galaxy of information here.

Upgrade to Britannica Online

Take a tour, New improved britannica online

Imagine Britannica's 32-volume encyclopedia online right there for you, plus full access to articles. Amazing content, written by world experts, that you can cite for projects and assignments.

Click here for Britannica shop

Landsat

officially Earth Resources Technology Satellites

Any of a series of unmanned U.S. scientific satellites. The first three were launched in 1972, 1975, and 1978. They were designed mainly to collect information about Earth's natural resources. They were also equipped to monitor atmospheric and oceanic conditions and to detect variations in pollution levels and other ecological changes. Three more Landsat satellites were launched successfully, in 1982, 1984, and 1999; radio communication with Landsat 6 was lost immediately after its launch in 1993.

Find more information on Landsat. Upgrade to Britannica Online for more on Landsat.

  • Get more

  • M?ss?ng more?

    Subscribers see 10 times more content. Just US $69.95 per year

  • Britannica, just as colourful as Hong Kong
  • Times may change, but insightful knowledge is still in demand. That's why Britannica brings a world of knowledge online, to Hong Kong. Have a look for yourself.