Telescope Technology Types of Telescopes Hubble Telescope and NASA’s Great Observatories

How Telescopes Work

Ground Based Telescopes Can only be used for electromagnetic radiation that can penetrate Earth’s atmosphere (longer wavelengths) Radio Telescopes - collects radio waves emitted by stars which is turned into images with computers Optical Telescopes – collect visible light from space objects…often housed in observatories  Reflecting  Refracting

Radio Telescopes

Largest Telescope on Earth Arecibo Radio Telescope – located in Puerto Rico

Generally, have to be very long and very expensive (due to the size of lens needed) to be powerful enough to see objects in any detail or very far away. Optical Telescopes - Refracting

Optical Telescopes - Reflecting Generally, can be built shorter but “fatter” to accommodate a large mirror...also, mirrors are much cheeper than lenses so reflecting telescopes are more affordable.

Space Based Telescopes – NASA’s Great Observatories Orbiting Telescopes no atmospheric interference Can detect all forms of electromagnetic radiation because there is no atmospheric interference in space A family of four orbiting telescope observatories which can each “see” a different type of radiation. They include:  Hubble Space Telescope  Spitzer Observatory  Compton Gamma Ray Observatory  Chandra X-Ray Observatory

Hubble Telescope Reflecting Telescope deployed by the shuttle Discovery in 1990 Orbits 380 miles above our planet Can see visible and ultraviolet light that would otherwise be blurred by Earth’s atmosphere Has provided much evidence for the expansion of the universe

Hubble Image

Compton Gamma Ray Launched in 1991 by the shuttle Atlantis Can read the most energetic form of radiation – gamma rays Gain information on: solar flares, gamma- ray bursts, pulsars, nova and supernova explosions, accreting black holes of stellar mass, quasar emission, and interactions of cosmic rays with the interstellar medium. Re-entered Earth’s atmosphere in 2000 and retrieved from the Pacific Ocean

Compton Whole Sky Image

Chandra X-Ray Deployed by the shuttle “Columbia” in Reads x-ray radiation Observes remnants of exploding stars

Crab Nebula – Remnants of Supernova Explosion Without Chandra Technology With Chandra Technology

Spitzer Infrared radiation reading telescope – reads the heat radiated by objects in space Infrared radiation is blocked by Earth’s atmosphere Launched in 2003 by a Delta rocket

Image of Spitzer

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