Classroom Discussion Activity

SALT: Imaging the Southern Sky

When South Africa decided to build a new telescope, it went big. As in rival-the-world’s-best big. With the participation of astronomy groups from all over the world, the Southern African Large Telescope, or SALT, is casting a wide eye on the southern sky. Moreover, it’s inspiring future astronomers in the region. This Science Bulletins feature takes you behind the scenes as this bold new telescope brings world-class astronomy to a developing nation.

This feature story is an illustration of the process of science. It features scientists collecting different kinds of data that will be used to help them examine questions they have about the universe (read more about The Scientific Process).

Class Discussion

Establish prior Knowledge
Point out to students that many of the world’s most powerful telescopes are positioned in the Northern Hemisphere. However, many of the Universe’s objects can be seen only from telescopes positioned in the Southern Hemisphere. These include our two nearest galaxies, the Large and Small Magellanic clouds, and the center of the Milky Way Galaxy. Up until recently, only a few telescopes in South America were available to astronomers. In 2005, however, the Southern African Large Telescope (SALT) was installed in Southerland, South Africa. This very powerful telescope can observe objects at the very edge of the Universe. Tell students that in the feature they are about to see, they will learn more about the SALT telescope.

Have students read the synopsis and then watch the video. As students watch the feature video, ask them to take notes. Have them identify the types of data the SALT telescope is collecting and how that data is used. Use these questions to guide a class discussion.

  • How is the SALT telescope different from other telescopes?
  • What are the two instruments on the telescope?
  • What does the imaging camera do?
  • What does the spectrograph do?
  • How do you think the data gathered by SALT will add to our understanding of the Universe?

Use this question to wrap-up the discussion.

  • What would you like to know about the Universe that SALT might help you find the answer to?

Direct students who wish to know more about spectroscopy to this activity from NASA.