2. planets moons asteroids comets stars
Celestial bodies:
A natural object out in space.
Includes:
planets moons asteroids
comets
stars

3. Stars: give off light and heat but are very far away. Ex. The Sun
Planets: ancient term meaning: moving stars.

4. The universe: the constellations
 Patterns
made up of stars.
The universe: the constellations

6. Orion: the hunter

8. Video: The Universe: season 2 Episode 10

9. paths called orbits. gravitational forces.
 Celestial bodies move in cyclic
paths called orbits.
 These orbits result from
gravitational forces.
 Planets, suns and moons revolve on a central axis.

10. to west. Stars generally move from east
 The point around which the stars rotate is the North Star… Polaris.
Ursa Major and Minor, and Cassiopeia never go below the horizon. --Circumpolar
Video: The Story of Science- What is out there? V

11. Aristotle ( B.C.E.)
Visualized the universe as being geocentric. This means the Earth is the centre of the universe and everything else revolves around it.

12.  He believed that the Earth was a sphere due to the curved edges observed during a lunar eclipse.

14. loop or s-shape in the sky.
Ptolemy ( C.E.)
 Based his model on his observations of Mars.
Mars orbital path creates a
loop or s-shape in the sky.
 His model showed each planet attached to a crystal sphere with its centre at Earth.

15. (epicycle). nearly 15oo years.
 Each planet was not attached directly to its sphere but to an off-centre wheel
(epicycle).
 Accepted for
nearly 15oo years.

16. Used to locate and predict the position of the Sun, Moon and stars.

17. observations to be made.
 Along with a compass, it could be used to describe the position of any celestial body in relation to the direction North and to the horizon.
 Allowed for more accurate
observations to be made.

19. universe (Sun at the centre).
Copernicus ( )
 Believed in a heliocentric
universe (Sun at the centre).
 The Earth rotated on its axis once daily and revolved around the Sun once a year.

22. Galileo (1564-1642) about 20x closer.
 First person to view the “heavens” through a telescope.
 Allowed him to see objects
about 20x closer.

23. He observed:
Craters on the Moon
Spots on the Sun
Four “stars” orbiting Jupiter
(called the Galilean Moons)

24. Now that the Sun was placed at the centre of our solar system, other astronomers could work to understand the motion of the planets.
Improvements in the telescope would show new and strange objects never imagined!
Tyco brahe video V

25. All planets move in ellipses with the Sun at one focus.
Johannes Kepler ( )
Developed 3 Laws of Planetary Motion
All planets move in ellipses
with the Sun at one focus.
Planets sweep out at equal areas of their elliptical orbit in equal times.
Video: Tyco Brahe, kepler and Planetary motion - space folder V

26. 3. The time a planet takes to revolve around the Sun is directly related to how far away it is from the Sun.

27. I ry I

29. gravity affects all celestial bodies, causing them to stay in orbit.
Sir Isaac Newton ( )
Developed the three laws of
motion.
 First to show that the force of
gravity affects all celestial bodies, causing them to stay in orbit.

31. Invented the reflecting telescope which uses a curved mirror to focus the light to a point at an eyepiece.

32. Inner Planets Jovian Planets Mercury  Venus  Earth Mars Jupiter
Saturn
Uranus
 Neptune

33. Video: The relative size of Planets- grade 9 space folder
Activity V