Guiding Questions

• Why is it important that telescopes be large?

• Why do most modern telescopes use a large mirror rather than a large lens?

• Why are observatories in such remote locations?

• Do astronomers use ordinary photographic film to take pictures of the sky? Do they actually look through large telescopes?

• How do astronomers use telescopes to measure the spectra of distant objects?

• Why do astronomers need telescopes that detect radio waves and other nonvisible forms of light?

• Why is it useful to put telescopes in orbit?