Viewing the universe
Descriptive vocabulary
What is astronomy?
Objectives
Identify the visible and non-visible parts of the electromagnetic spectrum.
Compare refracting telescopes and reflecting telescopes.
Explain how telescopes for non visible electromagnetic radiation differ from light telescopes.
Astronomy vocabulary
Galaxy
The galaxy is a collection of stars, dust, and gas bound together by gravity. Our galaxy is the Milky Way galaxy which contains our solar system.
Astronomical unit
The astronomical unit is the average distance between the earth and sun; which is approximately 150 million kilometers.
Electromagnetic spectrum
The electromagnetic spectrum is all the frequencies or wavelengths of electromagnetic radiation.
Refracting telescope
A refracting telescope is a telescope that uses a set of lenses to gather and focus light from distant objects.
Reflecting telescope
A reflecting telescope is a telescope that uses a curved mirror to gather and focus light from distant objects.
Light year
Astronomers use the speed of light to measure distance. Light travels at 300,000 km/s. In one year, light travels 9.46 times 10 to the power of 12 km. this distance is known as a light year.