Galileo Events in Astronomy
Galileo was an incredibly influential person in the field of astronomy and science in general. There are several Galileo events in astronomy that helped shape the field and how humans perceive the solar system and the universe. Galileo did not build the first refracting telescope, but he did build a refracting telescope that had higher magnifying power than the model that he based his design on. His telescope design allowed him to observe the planet Jupiter and when he looked at it he noticed four objects close to the planet. After observing the objects for a few nights, he concluded that they orbited the planet. His discovery of Io, Europa, Ganymede, and Callisto, four of Jupiter's moons, is one of the major Galileo events. This discovery conflicted with the idea that the universe is geocentric, since in that model everything revolves around the earth.
One of the other major Galileo events, is his observation of Venus. He discovered that he could observe all of Venus' phases, just like the Moon. The fact that he could observe Venus go through its phases meant that the planet had to have been revolving around the sun, and not the earth. Galileo was also the first person to discover that the Moon was rough and had craters and mountains. He also observed Saturn's rings and Neptune, but at the time when he observed Neptune he did not realize what it was and believed it was just an unremarkable dim star. Galileo was an incredibly important figure in astronomy, and helped to advance the science in many ways.
Hubble Space Telescope
The Hubble Space Telescope is a collaboration between NASA and the European Space Agency.
Reflecting telescopes are used to reflect light by using curved mirrors to provide a distant image.