1. Observing and exploring space
Chapter 1.1 Telescopes
Part 2

2. How are we… able to see the color of Saturn’s Rings?
able to tell that the moon has craters
You could use a device called a telescope.
Telescope- is an instrument that gathers electromagnetic radiation from objects in space and concentrates it for better observation

3. Optical Telescopes Most common of telescopes.
The optical telescope collects visible light and focuses it to a focal point for closer observation
Focal Point- the point where rays of light that pass through a lens or that reflect from a mirror and meet.

4. Refracting Telescopes
Refracting Telescopes- uses a set of lenses to bend and focus light
Galileo helped to build these
The earliest telescopes were all refractors

5. Disadvantages of Refractors
These are good to observe objects within our solar system
Since light is refracted… Images are not always focused
Refracting telescopes need to be stronger in order to support the heavy glass

6. Reflecting Telescope ~ 1670 Sir Isaac Newton built a different kind
Reflecting Telescope- uses a set of curved mirrors to gather and focus light from distant objects.
Largest optical telescopes are Reflectors

7. Why reflecting telescopes?
Mirrors are lighter, so they are able to be larger
The larger the mirror the more light being gathered
Flaws in the glass does not affect light because curved mirrors are polished.

8. Radio Telescopes Very large and look like satellite dishes
The telescopes below are linked together by a computer

9. Arecibo Observatory
Largest Radio Telescope located in Puerto Rico

10. Earths Atmosphere and Telescopes
Why do you think most observatories are located on high mountains?
Light pollution blocks some of the radiation
Atmosphere distorts the light which is why some stars seem to twinkle
Where would be the best location to place a telescope?

11. Space Telescopes
Space telescopes have no interference since they orbit outside of the atmosphere
Hubble telescope has been orbiting since 1994

12. What did we do before Telescopes?
The sky has been studied for thousands of years
Motion of the stars helped keep track of seasons
Stars were so important that they were placed into Constellations, patterns in the sky
Greek astronomers saw “stars” move across the constellations know now as Planets

13. Galileo’s Observations
In 1610 Galileo look at the night sky and began his discoveries of the following
More to the night sky and the Milky way is made up of many stars
Moon has craters
Venus has phases
Jupiter has moons
Sun has dark spots
Now, we can use binoculars to study this information