The document discusses astronomy and different types of telescopes. It describes refracting telescopes which use lenses and reflecting telescopes which use mirrors. Most large telescopes are reflecting telescopes because it is easier to build large mirrors. Invisible light telescopes can detect wavelengths like radio waves and infrared that are not visible to the human eye, allowing astronomers to gather information about objects in space that can't be observed with visible light telescopes.

2. Astronomy
The study of the universe which is everything that exists ,including Earth ,the planets ,the
stars and all space.

3. Telescope
• A device that collects light and magnifies images to make distant objects
appear closer ,larger and brighter.

4. Types of Telescopes
Using invisible light
Any light frequency in
electromagnetic
spectrum that people
cant see
Using visible light
The light that you can see
and detect with your eye

5. Visible light Telescope
Refracting Telescope Reflecting Telescope

6. RefRacting telescope
• It uses lenses to gather light from faraway objects .
• In refracting telescope the light is bent and focused on
objective lens.
• The image is then magnified by lens in the eyepiece.

7. Reflecting telescope
0
• Visible light reflects off a series of 2 or more mirrors, which amplify
the image before it reaches the lens in the eyepiece.

8. What kind of telescope would you expect to
find in most observatories?
• It is easier to build large mirrors together more light
so most large telescopes are reflecting telescopes.

9. Invisible light Telescope
• Invisible light frequency in electromagnetic spectrum that
people cannot see.
• Special telescopes can detect waves such as radio
waves ,radar, infra red waves ,ultraviolet light , X-ray.
• These telescopes can gather information that cannot be
observed using visible light.

10. Why might astronomers study objects in space
with an infrared telescope?
To gather information not obtainable with
visible light ,like X-rays.

11. Earths’ rotations
• thE Earth has 2 typEs of MovEMEnts:
1)rotation of Earth around itsElf (its
axis)
2)rEvolution of Earth around thE sun
(thE path in which thE Earth rEvolvEs
around thE sun is callEd : orbit )

12. 1)Earth’s rotation around its axis
Earth’s axis
is an imaginary line that
passes through the north
and the south pole
The part of the Earth away
from the Sun
Night
The part of the Earth facing
the Sun
Day Time

14. • thE Earth takEs 24 hours to rotatE around its
axis or itsElf .
• this rotation rEsults in
day and night
whErE thE part of thE Earth facing thE sun is
“day tiME” and thE part away froM thE sun is
“night”

15. Shadow

16. Shadows

17. Exploring SpaceSpace probes send images and data back to Earth for scientists to
interpret.
Artificial satellites are sometimes sent into space by astronauts on a
space shuttle (reusable spacecraft).
After the mission astronauts ride back to Earth in the shuttle.
“Hubble Space Telescope”

18. What is the difference between planetary images taken
from Earth and those taken from space?
• Images taken from Earth would have
less sharpness and detail than those
taken from a satellite or a probe
because Earth’s atmosphere would
interfere with the quality of photos

19. 2)The earTh’s revoluTion around The
sun

20. • The revolution of Earth around the sun results in
Four Seasons