Describing The Universe
The Electromagnetic Spectrum and Telescopes
What is Astronomy?
Objectives
1. Identify the visable and nonvisible parts of the electromagnetic spectrum.
2. Compare refracting telescopes and reflecting telescopes.
3. Explain how telescopes for nonvisible electromagnetic radiation differ from light telescopes.
Astronomy Vocabulary
Universe
The Universe is commonly defined as the totality of existence, including planets, stars, galaxies, the contents of intergalactic space, and all matter and energy.
Light Year
The distance that travels in one year; about 9.46 trillion kilometers.
Astronomical Unit
The average distance between the Earth and the Sun; approximately 150 million kilometers
Electromagnetic Spectrum
All of the frequencies or wavelengths of electromagnetic radiation.
Refracting Telescope
A telescope that uses a set of lenses to gather and focus light from distance objects.
Reflecting Telescope
A telescope that uses a curved mirror to gather and focus light from distant objects.