Which instrument is used to observe distant objects?

A telescope is an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects.

The earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope. The actual inventor is unknown but word of it spread through Europe. Galileo (astronomer, physicist and engineerб 15 February 1564 – 8 January 1642) heard about it and, in 1609, built his own version, and made his telescopic observations of celestial objects.

In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s.