Different wavelengths of the electromagnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe
Radio Waves and the Universe
Many astronomical objects emit radio waves
Astronomers can make pictures from the radio waves being emitted
Radio telescopes use a large metal dish to help detect radio waves
By studying the radio waves, astronomers can learn about the composition, structure, and motion of objects
Radio astronomy has the advantage that sunlight, clouds, and rain do not affect observations
What do Radio Waves show us?
The above image shows the Carbon Monoxide (CO) gases in our Milky Way galaxy
Radio Waves
Microwaves and the UniverseBecause microwaves can penetrate haze, light rain and snow, clouds and smoke, these waves are good for viewing the Earth from space
Microwaves
Infrared Rays and the UniverseSatellites, like the Infrared Astronomy Satellite (IRAS) look up into space and measure the infrared light coming from things like large clouds of dust and gas, stars, and galaxiesInfrared Universe Exploring the Infrared Universe
Sunflower Galaxy Glows with Infrared Light
Ultraviolet and the Universe We can study stars and galaxies by studying
the UV light they give off
Many scientists are interested in studying the invisible universe of ultraviolet light, since the hottest and the most active objects in the cosmos give off large amounts of ultraviolet energy
Andromeda Galaxy in Ultraviolet
X-Rays and Gamma Rays and the Universe
Many things in space emit X-rays, among them are black holes, neutron stars, binary star systems, supernova remnants, stars, the Sun, and even some comets!
This radiation has such high energy that specially made, angled mirrors must be used to help collect this type of light
X-Rays and Gamma Rays and the Universe
X-ray and gamma-ray astronomy has led to the discovery of black holes in space, and has added much to our understanding of supernovae, white dwarfs and pulsars
High-energy observations also allow us to study the hottest regions of the Sun's atmosphere
The Beautiful Universe
Exploring the Universe through Gamma Rays
Spectrographs
Astronomers use spectrographs to gather information about stars, including their chemical compositions and temperatures
Chemical Composition
Chemical elements in a star’s atmosphere absorb light from the star
Each element absorbs light at different wavelengths, and each absorbed wavelength appears as a dark line on a spectrum
By comparing a star’s spectrum with the known spectrums of different elements, we can determine which elements are found in stars
Hydrogen