Did you know an accident led to the invention of the telescope. During the year 1608 a Dutch lens maker named Hans Lippershey was working with  lenses like he did every day.  By accident he placed one of the lenses he was holding in front of the other one he was holding. When he did that he noticed that the image was larger than what he saw with only one lens. That is what led to the invention of the telescope.  

Hans Lippershey created no telescope but the main idea of his finds spread quickly. In the year 1609 an Italian scientist named Galileo heard of the telescope. He quickly built a telescope for himself so he could observe the stars. The telescope that he built was the first telescope ever built. What Galileo discovered was more stars than he could ever imagine.  this discovery changed astronomy forever.

The picture to the upper left shows one of Galileo's telescopes. His type of telescope was called a refracting telescope. To make this kind of telescope you have to put a large lens at one end of a tube. When the lens collects some light it sends it to the other side of the tube to a smaller lens. From the small lens it is sent to a magnifying lens which is used to make the image big enough for us to see. Lenses were added and taken away to improve the image. The picture to the upper right hand side shows some replica's of the telescopes Galileo used to own. The picture in the center are two telescopes that really belonged to Galileo. They can be found on display at the Tribune did Galileo in Florence, Italy.

Gregory conjured up the idea of a new telescope. But Sir Isaac Newton was the first person to make the reflecting telescope. It was made in the year 1668. The idea of the reflecting telescope is to use mirrors instead of lens. An end of a tube is left open to let light in. When the light enters it hits a mirror at the other end of the tube. The light reflects up to a smaller mirror then into a magnifying lens. Of course the design of this telescope has improved since Newton invented it.

It is the eighteenth century an English astronomer named William Herchel built the largest telescope in his time. The mirror of the telescope was four feet wide and forty feet long. Whenever people asked about his telescope Herchel replied that he wanted magnification and the right light gathering capability. With his new telescope he discovered the planet uranus as well as two of its moons and two of Saturn's moons.

Today both reflecting and refracting telescopes are used in astronomy. But most of the world's observatories use reflecting telescopes because they are cheaper and can be made alot larger. Special kinds of telescopes can pick up infared, x-ray, or other high energy sources. The picture on the right is an infared telescope. The picture on the left is the most distinctive picture of Mars ever taken. The Hubble Space Telescope took this picture.