Before we had amazing technology that allows us to send telescopes into space, travel to the moon or even use a simple pair of binoculars to look into the night sky, people did not have a clue as to what mysteries the universe might hold.In 1608, however, a simple child’s spyglass was turned into a telescope and in 1609, a man named Galileo Galilei modified the telescope and turned it to the heavens, revealing planets, sunspots, mountains and craters on the moon.

Four hundred years later, we find ourselves celebrating the 2009 International Year of Astronomy.

When Galileo turned his telescope to the night sky, he made amazing discoveries that would eventually change the way people viewed the solar system and universe.

Before getting into some of Galileo’s discoveries, let’s take a step back and wonder what it was like before telescopes.

People believed in the geocentric theory, which states that our Earth is in the center of our solar system, and the planets, sun and stars orbit Earth.

There weren’t telescopes then, so people didn’t have evidence to support any other theories.

Galileo’s telescope was rather small.

It didn’t have a lot of power and the resolution was poor. Finding objects throughout the night sky would be rather difficult to accomplish. So he decided to observe the moon since it is big and bright and easy to find even with a small telescope.

When he observed the moon, he was blown away.

He saw that the moon had mountains and craters on it. It didn’t have the smooth surface that everyone thought it had. This observation was important because a door was opened for new possibilities for the composition of the solar system.

If the moon was different, what else could be?

Galileo, in January of 1610, decided to turn his telescope to Jupiter.

He was shocked at what he observed.

Jupiter, as it turned out, was a completely different world, different from the Earth and it had its own moons.

Before telescopes, people believed that planets were magical stars that wandered around our night sky, so discovering a whole new world was a great honor and Galileo was excited.

In December of 1610, Galileo made a new discovery that would challenge the geocentric theory.

He observed Venus and noticed how, over time, Venus waned and waxed like the moon.

This is Galileo’s most important discovery because it was the evidence that proved that the sun is in the center of the solar system, or the heliocentric theory.

After he made these amazing observations and discoveries, he began sending his evidence to scientists all around the world, and they began building bigger and better telescopes.

Eventually the heliocentric theory was accepted through enough evidence.

It is also important to know that Galileo was placed under house arrest by the Roman Catholic Church at the time because he was publishing his work so ordinary people could see what was happening with science and they didn’t like that.

He passed away while still under house arrest in Florence, Italy.

The moral is to do whatever you believe in and don’t let others stop you.

Galileo did what he had to do to get the message out that our solar system was composed in another way, and now the way we look at the universe is completely different from four-hundred years ago.

So grab a pair of binoculars and take a look into the night sky, you never know what you will find.

Who knows, maybe you will discover something fascinating.