Telescopes What is the purpose of a telescope? To gather electromagnetic radiation in the form of visible light. It magnifies the image so “we” can see that image more clearly & it enlarges the image for detailed observations.

Refractor Telescope A refractor telescope uses a lens to gather light. It has an objective lens (convex) and an eyepiece which enlarges or magnifies the image. Light travels in straight lines.

Reflecting Telescope A reflecting telescope has a curved mirror that gathers light which can be reflected to a smaller mirror that focuses image for the eye to see.

Telescopes What is the main difference between a refractor & reflector telescope? Why are visible light telescopes built on mountaintops in rural areas? What prevents telescopes on Earth from seeing clearly that telescopes in space do not have to deal with?

Electromagnetic Radiation Electromagnetic radiation is energy that travels through space in the form of waves. These waves have varying lengths. Some are long and some are very short.

Electromagnetic Radiation

Electromagnetic Radiation These waves are energy. (Energy is the ability to cause change. 2 types of energy: potential – which is stored energy and kinetic – energy which is in motion) The Earth receives energy from the sun in the form of radiation. Our eye can “see” the middle of the electromagnetic waves which is visible light.

Electromagnetic Radiation A prism (which is a transparent object – can be glass, water or air) breaks up or separates visible light into a band of colors. The rainbow – red, orange, yellow, green, blue, indigo and violet. Or…… Roy G Biv These colors are called a spectrum. The colors are separated by the length of their waves (wavelengths).

Wavelengths

Electromagnetic Wavelength A wavelength is the distance between one wave peak and the next wave peak. Red has the longest wavelength and violet has the shortest.                                                                                                     <>

Wavelength

Electromagnetic Radiation Can you make up a mnemonic or silly saying to remember the order of wavelengths for the electromagnetic radiation? From longest to shortest: Radio, microwaves, infrared, visible, ultraviolet, x-rays & gamma rays

Types of scopes A radio telescope can pick up radio waves. These waves are not affected by clouds or bad weather. These telescopes can be located at low altitudes because they pass freely through Earth’s atmosphere. Spectroscope – used to break up or separate electromagnetic radiation. Allows astronomers to “see” what type of energy an object is emitting.

Types of scopes Radio waves from galaxy

Types of scopes X-rays from space

Types of scopes Picture of Milky Way Galaxy from Hubble

Types of scopes Infrared of Milky Way Galaxy