The First Telescopes
Telescopes in astronomy. Humankind has always been fascinated by the stars, the moon, and the planets. However, it was only in 1608 that the first telescope was patented and only a select few could look at the night sky like never before. A year later Galileo Galilei built his own, much-improved telescope. With about 20x magnification, it would help him discover some previously unknown facts about our solar system.
The first large reflector telescope was built in 1789 and was about 12 meters long. This large telescope was built in the United Kingdom and based on Newton’s reflector telescope. It was called the Herschelian Telescope.
Reflectors vs Refractors
The difference between these two is basically in the names. A reflector uses mirrors to reflect an image back towards your eye. The telescope usually has a hole at the one end and a bowl-shaped mirror at the other side. The light reflects off the bowl and through to the eyepiece.
Refractors use lenses that gather light that is then sent to the eyepiece. At the eyepiece the image is magnified and for you to see. This means that refractors bend light.
A third option is also available and is called a Catadioptric telescope and use a combination of mirrors and lenses to form an image.
Types of Telescopes
Many types of telescopes are in use by science to explore the universe. Not all telescopes work by using normal light. The best way to classify telescopes in astronomy is by the light wavelengths that they detect. Here is a list of the types of telescopes in use:
- Radio Telescopes
- Microwave Telescopes
- Infrared Telescopes
- Optical Telescopes
- Ultaviolet Telescopes
- X-Ray Telescopes
The wavelengths of these telescopes start at about 0.01 nm in X-Ray telescopes, going up all the way to a kilometer in radio telescopes.
The Hubble Telescope
The Hubble Space Telescope is probably one of the best-known telescopes in use today. It was first launched in 1990 and is still in use today, almost 30 years later. The Hubble, named after the American astronomer Edwin Powell Hubble, use a mirror of almost 8 feet.
What makes the Hubble so special is that it is equipped to be used as 4 different types of telescopes. Ultraviolet, visible, near infrared, and even regions of the electromagnetic spectrum. Another interesting fact about the Hubble is that it is the only space telescope that was designed to be maintained by astronauts in space.