How Do Astronomers

Gather Information

About Space?

TEKS 8.8C explore how different wavelengths of the

electromagnetic spectrum such as light and radio waves are

used to gain information about distances and properties of components of the universe

Most of the information we have about the universe

comes from radiation.

Objects in the universe, such as stars and galaxies, emit radiation.

This radiation travels as waves. Different kinds of radiation have differing wavelengths and energies.

We cannot see most of the radiation, but telescopes are used to collect the radiation for astronomers to study.

The entire collection of different kinds of radiation is called the Electromagnetic Spectrum.

The electromagnetic spectrum is a continuum of waves divided into regions based on wavelengths.

At one end of the spectrum are radio waves, which allow you to listen to your favorite radio station.

In the central portion is the only part of the spectrum you can see with your eye, the visible region.

Most of the visible region comes from the Sun.

When light is passed through a prism, it bends

and separates into its different wavelengths.

Spectroscopy is the study of the spectrum.A spectroscope is

used to separate light into its component wavelengths so that they can be studied.

The pattern of wavelengths and colors

is called a spectrum.

By obtaining and analyzing the

spectrum from a distant object,

astronomers can determine the object’s temperature, density,

direction of motion and composition.

Each element composing a star has a unique spectrum. Just

like a fingerprint…..

Astronomers use the spectral patterns from stars and other objects to determine what elements compose the object.