2. Telescopes 1608, Lippershey earliest known working telescope & first to apply for patent Refracting telescope- bends light through a lense and into the eyepiece. Worked but had some issues: Limited size of lens Flipped image Chromatic aberration- when lens fails to focus all of the colors of the visible light spectrum at the same time.

3. Galileo 1 st built by Galileo 1609 Galileo DID NOT invent the telescope Heard of Lippershey design idea 1608 Refined the design 3x - 30x magnification Discovered 4 largest moons of Jupiter Craters & Mountains on the moon (topographical maps) Rings around Saturn The phases of Venus (similar to the moon’s-proving heliocentric model) The planet Neptune That the Milky Way was tightly packed stars not just nebula.

4. Isaac Newton Built 1 st reflector telescope in 1668 using mirrors instead of lenses to redirect the light into the observers eye. All major optical (light we can see) research telescopes are now reflecting telescopes Advantages over refracting telescope Only one side of mirror has to be polished/flawless Mirror can be bigger than lenses because they can be supported from behind No chromatic aberration.

5. Refracting & Reflecting Telescopes Refracting- light bends or refracts when going through a lens Reflecting- light is reflected off main curved mirror angling it to a secondary mirror that redirects light to the eyepiece.

6. Mount Wilson Observatory Mount Wilson Observatory 1908 Designed by George Ellery Hale Used by Edwin Hubble to: Discover a way to calculate distances stars are from us Prove the universe went far beyond The Milky Way Before this time it was believed that The Milky Way was the universe Create Hubble’s Law.

7. Hubble Space Telescope Launched 1990 @ cost of $1.5 billion Reflecting telescope 7.9 foot mirror First pictures were fuzzy 1993, mirror replaced due to manufacturing defect 1/50 th the thickness of a piece of paper.

8. Hubble Allowed us to see into deep space Hubble Deep Field Patch of “empty” sky 10 days 3,000 galaxies NASA plans to Replace Hubble with James Webb Telescope 2018.

9. Kepler Space Telescope Kepler was launched March 2009 Mission is to hunt for terrestrial (rocky) planets in or near the habitable zone from their star Habitable zone-Distance where we believe liquid water could be present Found 1,700+ exoplanets (planets outside our solar system) since launch.

10. Other types of telescopes Radio Telescopes- observe radio and microwaves Infrared Telescopes- observe infrared light Ultraviolet Telescopes- observe ultra-violet light X-ray Telescopes- observe x-rays Gamma Ray Telescopes- observe gamma rays Certain sections of the electro-magnetic spectrum are visible from Earth, while others are only (mostly) observable from space. This is due to our atmosphere and its ability to block portions of the EM spectrum. Great for our survival, but bad for astronomy on Earth.

11. Parts of a telescope Objective- first lens or mirror that light passes through or reflects off of Eye-piece- lens or mirror light passes through or reflects off of before entering the eye Optical Tube- is the chamber light passes through between lenses/mirrors Secondary Mirror-second mirror light reflects off of before being sent to eye-piece in some reflecting telescopes.