What Channel is That?

Visible light is a form of electromagnetic radiation.

Others include: Radio waves Infrared waves (heat) Ultraviolet waves X-rays Gamma rays

Radio Astronomy: Use of radio waves to learn about composition of

stars

Are a very important type of EMR in our daily lives!

Objects in the universe also emit radio waves.

Radio telescopes capture radio waves emitted by radio objects. they allow scientists to “see” objects never seen

before because radio waves penetrate through dust particles where visible light cannot.▪ Computers are hooked up to radio receivers that

convert the radio waves into a colour picture for us to see.

Interferometry: Methods of connecting two radio

telescopes together to produce one large telescope (like light telescopes)▪ Example: Very Large Array (VLA) in New

Mexico▪ Very long baseline interferometry (VLBI)▪ Uses computers to connect as many radio telescopes

as they want together to produce an image. Images can be seen up to 100X in detail

There is a radio dish in space Allows scientists to make a telescope

twice Earth’s diameter,▪ They can image objects over 13 billion light

years from Earth!

Built the first radio antenna

Discovered radio waves that were interfering with telephone calls were coming from space!

Radio waves are recorded and graphed

Today, computers incorporate color for signal strength

Astronomical Unit (AU): is the distance from Earth to the Sun (150 million km)

1 light year = 9,460,800,000,000 km = 63,240 AU

Astronomers measure astronomical distances in light years – how far lightcan travel in one year.

Make an Electromagnetic Spectrum! Include:

All types of EMR One fact about each type Wavelengths (diagram and numbers) Frequency (numbers)