A refracting telescope works by bending light with its lenses. It gathers and focuses the light by using the objective lens to make a small image of the object and using the eyepiece lens to magnify the image.Know More
The lens' curvature also influences the quality of the telescope's images. The size of the image that the lens produces is directly related to the lens' focal length. As the focal length increases, the size of the image also increases. This is one of the refracting telescope's disadvantages since a long focal length means a long telescope. Other disadvantages of the refracting telescope include the inability to transmit all the light since some light is lost to absorption or reflection and large lenses that can be difficult to make.
Galileo created the first refracting telescope using a convex primary lens and a concave eyepiece lens. To enable his telescope to produce as clear of an image as possible, Galileo used math to calculate the distance between the lenses. He was able to see only a small part of the sky at any time, and the telescope produced fuzzy images from spherical aberration. This early telescope magnified objects three times, and his later creations were able to magnify objects up to 30 times.Learn more about Astronomy
Among a variety of aspects to consider when choosing a telescope, aperture is one of the most important for buyers to consider. The aperture affects the ability of the telescope to gather light and helps to make otherwise dark elements in the sky visible. However, increasing the aperture increases the diameter and weight of the telescope, so choosing too large an aperture makes the scope less portable.Full Answer >
A catadioptric telescope, also known as a compound telescope, is an optical system that uses a combination of lenses and curved mirrors to offer a wider field of view with a lower probability of error than earlier types of telescopes. Astronomers built the first catadioptric telescopes in the 1930s.Full Answer >
At the time of its launch in 1990, the Hubble Space Telescope had cost $1.5 billion to develop and construct. Additional costs were incurred to service the Hubble, the first space-based telescope, once it was placed in low Earth orbit.Full Answer >
The James Webb Space Telescope is said to be the most powerful telescope in the world as of 2014. However, NASA is already building the Advanced Telescope Large-Aperture Space Telescope, which is expected to be even more powerful.Full Answer >