1. Observing and exploring space
Chapter 1.1 Telescopes
Part 1

2. Observing and Exploring Space
Why do you think Astronomy is one of the most unique subjects in Science?
Astronomers have to observe their subjects at a very large distance
Only objects that Astronomers can physically study are meteorites
What do Astronomers use to study these distant objects?

3. Electromagnetic Spectrum
Astronomers use the light that travels through space to study the objects in space.
Not all light is visible by the naked eye
Electromagnetic Spectrum: energy that travels in the form of an wave

4. Light Light travels at 300,000,000 meters per second
670,000,000 miles per hour
Light Year: the distance that light travels in one year
9.5 trillion kilometers

5. Light What is the closest star to us? Sun 2nd - Proxima Centauri
4.22 light years away
Our Galaxy, the Milky Way is roughly light years across

6. Light
So, when you look up at space, you are really looking back in time. Why?
It takes time for the light of that object to travel to us
Andromeda is our closest galaxy
2.5 million light years away
When you look at the galaxy you are looking at the light that was given off 2.5 million light years ago

7. Electromagnetic Waves (EM)
Electromagnetic Waves have two parts
Electrical
Magnetic
Both work together to create the wave

8. Waves
Wavelength: is the horizontal distance between two of the same points on the wave
Frequency: measures the number of wavelengths that pass a given point

9. Waves of the Electromagnetic Spectrum
Ultraviolet
Rays
Gamma Rays
Radio Waves
Infrared Rays
Visible Light
X-Rays
Microwaves

10. Electromagnetic Spectrum
Visible light is the only and small part of the spectrum that humans can see
Includes all the colors organized by wavelength size

11. Electromagnetic Spectrum Facts
Some very hot stars emit light primarily at Ultraviolet wavelengths
Extremely hot objects emit X-rays and gamma rays
Cool stars shine mainly in infrared light
Faintest and most distant objects come in the form of Radio waves