TelescopesTelescopes

Device used to collect Device used to collect Light and to Magnify Light and to Magnify Distant ObjectsDistant Objects

Plans made by Plans made by Rodger Bacon 13Rodger Bacon 13thth Century Century

Galileo improved the Galileo improved the DeviceDevice

Bacon and GalileoBacon and Galileo

Some HistorySome History

Galileo was first to use the telescope to Galileo was first to use the telescope to view the night time skyview the night time sky

Devised a method to smooth and polish Devised a method to smooth and polish the lensesthe lenses Made image clearer (focus)Made image clearer (focus) First telescope 8x the MagnificationFirst telescope 8x the Magnification During his Studies increased to 32x the During his Studies increased to 32x the

MagnificationMagnification

Types of TelescopesTypes of Telescopes

OpticalOptical Gathers and Focuses Visible LightGathers and Focuses Visible Light

RadioRadio Directional Radio Antennae Directional Radio Antennae

Gamma and X RayGamma and X Ray Heavy Metal ReflectorsHeavy Metal Reflectors

Optical TelescopesOptical Telescopes

Three Types of Optical TelescopesThree Types of Optical Telescopes RefractingRefracting ReflectingReflecting

• Uses Mirrors to Produce ImageUses Mirrors to Produce Image• 1668, Most Common1668, Most Common

Catadioptric Catadioptric • Uses a Combination of Mirrors and LensesUses a Combination of Mirrors and Lenses

Refracting TelescopesRefracting Telescopes

Refracting TelescopesRefracting Telescopes Uses Lenses to Uses Lenses to

Produce ImageProduce Image Galileo 1600’sGalileo 1600’s Improved Improved

magnification 30xmagnification 30x Uses lenses to refract Uses lenses to refract

light (bend)light (bend) Yerkes in Lake Yerkes in Lake

Geneva (One of the Geneva (One of the Largest)Largest)

Refracting TelescopeRefracting Telescope

FlawsFlaws Chromatic AberrationChromatic Aberration

Shorter wavelengths are bent more than Shorter wavelengths are bent more than longer oneslonger ones

Weakens image and produces a halo of colorWeakens image and produces a halo of color When focusing on a red object, blue and When focusing on a red object, blue and

violet halo appearsviolet halo appears When focusing on a blue object, red and When focusing on a blue object, red and

orange halo appearsorange halo appears

Yerkes ObservatoryYerkes Observatory

Reflecting telescopesReflecting telescopes

Reflecting TelescopesReflecting Telescopes NewtonNewton

Used concave mirrors Used concave mirrors that focuses the light that focuses the light in front of the mirror in front of the mirror rather than behindrather than behind

Mirror is finely grained Mirror is finely grained and coated with and coated with aluminumaluminum

Reflecting TelescopeReflecting Telescope

AdvantagesAdvantages Light doesn’t pass through mirrors so Light doesn’t pass through mirrors so

glass doesn’t have to be of optical qualityglass doesn’t have to be of optical quality Mirrors can be supported fully from Mirrors can be supported fully from

behind, whereas lenses can only be on the behind, whereas lenses can only be on the sides which makes lens sagsides which makes lens sag

MagnificationMagnification

MagnificationMagnificationFocal Length of ObjectFocal Length of ObjectFocal Length of Eye PieceFocal Length of Eye Piece

Radio TelescopesRadio Telescopes

Collects Radio Waves with Huge DishesCollects Radio Waves with Huge Dishes Focuses incoming radio waves on an Focuses incoming radio waves on an

antenna, which absorbs and transmits antenna, which absorbs and transmits these waves to an ampliferthese waves to an amplifer

Interferometry: Linking separate Interferometry: Linking separate telescopes together to form one great onetelescopes together to form one great one Helps to pinpoint source of the radio wave Helps to pinpoint source of the radio wave

radiationradiation

AdvantagesAdvantages

Not affected by turbulence in the Not affected by turbulence in the atmosphere, clouds, and the weatheratmosphere, clouds, and the weather

No DomeNo Dome 24 hours a day viewing24 hours a day viewing Can see through interstellar dust which Can see through interstellar dust which

optical telescopes cannotoptical telescopes cannot

Types of TelescopesTypes of Telescopes

Satellites and ProbesSatellites and Probes

To get better pictures of Space, You need to To get better pictures of Space, You need to Leave Earth’s AtmosphereLeave Earth’s Atmosphere

The Atmosphere Distorts Incoming RadiationThe Atmosphere Distorts Incoming Radiation Hubble – 1990Hubble – 1990 Probes – Mars Odyssey 2001Probes – Mars Odyssey 2001 Chandra X-ray Observatory 1999 (Black Holes)Chandra X-ray Observatory 1999 (Black Holes) International Space StationInternational Space Station James Webb Space Telescope 2011James Webb Space Telescope 2011 Compton Gamma – Ray TelescopeCompton Gamma – Ray Telescope

Mars Odyssey and ISSMars Odyssey and ISS