• # Refractor Telescope

It all started when an Italian Mathematics professor Galileo Galilei wanted to be able to explore outer space in a more advanced way. This lead him to create a telescope that had two lenses, one primary and one concave. The telescope got the name Refractor because the bending of light is also known as a refraction.
• # 12 Foot Telescope (NO EXACT DATE)

Johannes Hevelius, a Polish man, built a 12 foot long telescope in hopes for better viewing.
• # James Gregory's Telescope (NO EXACT DATE)

Mathematician James Gregory envisioned a telescope that functioned by bouncing light between two mirrors with a hole in the middle to allow light to reach the light piece.
• # Newtons Refractor Completed (NO EXACT DATE)

In order to try and get rid of Chromatic Aberration, Newton used a polished metal mirror instead of a primary lens.
• # 150 Foot Refrator

Hevelius' 150 foot long refractor was completed.
• # Huygens' longest refractor

Dutch Astronomer Christopher Huygens made the decision to stop using tubes. Instead, he created Huygens' longest refractor, and instead made it mostly out of wire.
• # Chester Moor Hall solves Chromatic Abberation (NO EXACT DATE)

Chester Moor Hall was experimenting with lenses when he realized that he could use certain lens effects to solve on of the biggest road blocks in telescopes, chromatic abberation. The combination of concave lenses made of flint glass that spread light rays apart and convex lenses made of crown glass that bring light rays together would help cancel out chromatic abberation.
• # Spectroscope

Spectroscope was a tool created by Joseph Von Fraunhofer that was used to spread sunlight into colors and figure out what kind of elements make up stars. This tool is very helpful to astronomers.
• # John William Draper Takes First Picture of the Moon (NO EXACT DATE)

John William Draper worked to take the first picture of the moon by focusing a light sensitive photographic plate on the moon to keep the light in place on the moon as the earth rotated. After 20 minutes he took the first picture of the moon.
• # Harvard 15 Inch Refrator Completed (NO EXACT DATE)

The Harvard 15 inch refractor was completed. It was the largest telescope in America for 20 years created by William Cranch Bond. It had a 15 inch lens diameter and used clock work to keep it steady on the moon as it crossed the sky.
• # Bond and Wipple Photograph Vega

William Bond and photographer John A. Wipple took a photograph of the brightest star in consolation Lyrae Vega.
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## New Kind of Mirror Created

A new kind of mirror was created by German Chemist Justus von Liebig that used a new chemical reaction to cover the surface of glass with silver. This reflected 50% more light than metal mirrors.
• # New Material for Telescopes (NO EXACT DATE)

Carl August von Steinheil and Leon Foucault discovered that the new glass would be perfect for telescopes.
• # The Navel Observatory 26-inch Refractor Created (NO EXACT DATE)

The Navel Observatory 26-Inch Refractor was completed by telescope makers Alvan Clark and his grandson Alvan Graham Clark.
• # The Yerkes 40-inch Refractor Completed

The Yerkes 40-inch Refractor completed. It was the largest refractor telescope ever. It was built in Wisconsin at Lake Geneva.
• # Hooker 100-Inch Reflector

George Ellery Hale Created the Hooker 100-Inch reflector using silver coated glass mirror.
• # Coronagraph

The Coronagraph was created by Bernard Lyot to block some of the light from the sun, helping us see features that would otherwise be blocked by the sun's light. It does this by putting up a disk that blocks sunlight.

Rebers Radio Telescope was a telescope created to pick up radio waves from the sky.

Karl Jansky was the first to discover radio waves coming from the sky and space that could help us understand more about space.
• # Hale 200-Inch Reflector

George Ellery Hale created the Hale 200-Inch reflector using aluminum coated glass mirror.
• # BTA

Russian Astronomers created a telescope named BTA that is now the largest telescope ever in the world that has a single 236 inch mirror, but the photo quality is not as high as expected.
• # MMT Completed

The multiple mirror telescope (MMT) contained 6 aluminum coated glass mirrors that were supposed to be used for military satellites in the cold war, but the war was over and they were never put to use. Each piece was 72 inches.
• # Hubble Space Telescope Launched

The Hubble space telescope was launched into space. It was named Hubble after astronomer Edwin Hubble. The Hubble telescope was sent into space, getting a view that would never be possible through the atmosphere. It has majorly helped us research the age of the universe and how galaxies formed.
• # The Webb Space Telescope (YEAR UNKNOWN)

The date is unknown, but the Webb Space Telescope is soon to be launched. The telescope will view the universe in wavelengths that are not visible to the human eye. It will also view infrared light, which will allow the satellite to view objects behind layers of dusts that usually block objects in space. The beryllium glass will be coated in gold.