Astronomers have constructed telescopes of every kind - massive observatories designed to pick up faint traces of light across space.

Galileo climbed to the top of his house on Nov. 30, 1609, and used one of his early telescopes to observe the Moon. ... Galileo slowly moved his telescope’s aim over to a nearby object, the Moon.

1609: Refracting telescopes Image Title: “Galileo offering his telescope to three women (possibly Urania and attendants) seated on a throne; he is pointing toward the sky where some of his ...