Astronomers use telescopes because they're much better than our eyes. Here are a few reasons:
1. Telescopes see lots of colors - telescopes can collect light that our eyes are unable to: radio, microwave, infrared, ultraviolet, x-rays and gamma rays.
2. Telescopes collect lots of light - our pupils are only a few millimeters across, so we can only collect photons over a tiny area whereas telescopes can collect photons of huge areas (football fields worth for radio telescopes)
3. Telescopes see fine details - Because of the wave nature of light and the nerves in our eyes, we can only see details about the same angular size as Jupiter's width. Telescopes can allow us to resolve fine details - like Jupiter's Great Red Spot.
4. Telescopes can record observations with cameras - You can see things with your eye and draw them, but telescopes can share observations with the world! This is especially important for convincing skeptics what you saw was real!
This page was last updated July 18, 2015.