The Electromagnetic Spectrum And Telescopes

What is Astronomy?

Astronomy is the scientific study of the universe. Astronomers have been able to learn more about the origin of Earth and the process involved in the formation of our solar system.


  • Describe characteristics of the universe in terms of time, distance, and organization.
  • Identify the visible and nonvisible parts of the electromagnetic spectrum.
  • Compare refracting telescopes and reflecting telescopes.
  • Explain how telescopes for nonvisible electromagnetic radiation differ from light telescopes.

Astronomy Vocabulary

Differences between an astronomical unit au and light year

Astronomical unit and light year

An astronomical unit approximates the average distance between Earth and the sun, which is 149,597,870,691 km or about 150 million km.

A unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km.

The organization of the universe

In the universe there are 8 planets which are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune which this makes up the solar system and the Milky Way in the universe there are also stars and some of the planets are made up of gas and others of rock.

Describing the Electromagnetic Spectrum

The electromagnetic spectrum is all of the wavelengths of electromagnetic radiation. The things invisible and visible have in common is that they are both energy forms from the stars. They also travel in wave lengths and both form energy. Something different about visible and invisible is that when passing through prism it will always have the colors in the same order, which is visible. The blue and violet are the shortest, red and orange are the longest and this is visible. Each wavelength has its own color. Invisible is infrared, microwave, x-ray, gama rays, radio waves, ultraviolet rays.

Describing the Refracting and Reflecting Telescopes

Telescopes that use a set of lenses together and focus light from distant objects are called refracting telescopes. The reflecting telescope which uses a curved mirror to gather and focus light from distant objects. Both telescopes are used to study radiation and they also collect radiation. They are both optical telescopes. The refracting telescopes has an objective lens and focuses the light to be magnified by an eyepiece. It is a very difficult to make huge lenses with refracting. Reflecting telescopes has a curved mirror and it focuses the light on a second mirror. The second mirror sends it to the eyepiece. Reflecting can make the mirror larger and it is not difficult to make huge mirrors. A reflecting telescope gathers and analyzes more light.

Invisible light telescopes

An invisible light telescope has an electromagnetic radiation that provides scientist with information about objects in space. There are also telescopes that detect gramma rays, x-rays, and infrared rays. One problem with using telescopes to detect invisible electromagnetic radiation that Earth's atmosphere acts as a shield against many forms of electromagnetic radiation. The Hubble space telescope that has been launched from objects.