Transcript Telescopes
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.
Galileo
1st 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.
Isaac Newton
Built 1st 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.
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.
Hubble Space Telescope
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
1/50th the thickness of a piece of paper.
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.
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.
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.
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.