1. Space Science – Lesson 1: Components of Space

2. What are you made of? Space Science – Lesson 1: Components of Space

3. “The Most Astonishing Fact” Video Space Science – Lesson 1: Components of Space

5. Our Solar System Solar system: a star and all the objects that travel in orbit around it Our solar system is located in an outward spiral of Milky Way galaxy. From NASA at http://solarsystem.nasa.gov/planets/index.cfm Lesson 1 – Components of Space

7. Theories of the solar system There have been historically two models to explain the rotation of celestial objects around Earth: 1. Geocentric Model: Everything (sun & other planets) revolve around Earth Proposed by Pythagoras, an ancient Greek scientist We are the center of the universe Lesson 1 – Components of Space

8. Theories of the Solar System 2. Heliocentric Model: The Earth and planets revolve around the Sun - Heliocentric model (helio = Sun) - Proposed by ancient Greek, Aristarchus - Was rejected until the 1600’s But was supported by Polish astronomer Nicolas Copernicus and Galileo (1564–1642) supporter of Copernicus’s ideas In 1609, Galileo he used a telescope for the first time to view Moon and planets; observations exposed errors in the geocentric model

9. Despite the amount of evidence to support the heliocentric model, there are still people who reject his model. i Theories of the Solar System

10. What are some components of the Solar System? Space Science – Lesson 1: Components of Space Other space objects Planets Stars Comets Moons Asteroids Satellites Dwarf Planets

11. Space Science – Lesson 1: Components of Space

12. Components of Our Solar System Lesson 1 – Components of Space Key Terms: 1.Planet – object orbiting a star or stellar remnant that is big enough to be rounded by its own gravity 2. Dwarf Planet – much smaller than a planet (smaller even than Earth's moon) -Orbit the Sun just like the eight major planets -Not able to clear their orbital -E.g. Pluto

13. Key Terms: 3.Moon (natural satellite) – celestial body that orbits another body (e.g. a planet) 4.Star – huge ball of gas held together by gravity -Central core is extremely hot and produces energy -Some energy released as visible light 5.Meteroroids – Little chunks of rock and debris in space are called meteoroids -They become a meteor (shooting stars) when they fall through a planet's atmosphere -When they land on the ground they are called meteorites Lesson 1 – Components of Space

14. Key Terms: 5.Comet – snowballs of frozen gases, rock and dust -~ size of a small town -Dust & gases form tail that stretches away from Sun for millions of km -Has a very elliptical orbit 6.Asteroid – Rocky, airless objects that orbit the Sun -Too small to be dwarf planets & planets -Tens of thousands gathered in the main asteroid belt b/w the Mars & Jupiter -Asteroids that pass close to Earth called near-earth objects. 7.Satellite – artificial object that has been intentionally placed into orbit (different from natural such as the moon) Lesson 1 – Components of Space

15. “Our Solar System” Video Space Science – Lesson 1: Components of Space

16. Ancient astronomers saw points of light that appeared to move among the stars - They called these ‘planets’, meaning ‘wanderers’ - Named them after Roman gods Can you name the 8 planets? Hint: One is named after him  Planets The Solar System - Planets

17. Term ‘solar system’ derived from “sol” meaning the Sun 8 Planets (in order starting from closest to the Sun): 1. Mercury 2. Venus 3. Earth 4. Mars 5. Jupiter 6. Saturn 7. Uranus 8. Neptune *Pluto no longer considered a planet  known as dwarf planet planet Planets Mnemonic device: My Very Elegant Mother Just Served Us Nine Pizzas

18. 4 innermost planets called terrestrial planets (meaning “Earth-like”) - Almost circular orbits around Sun - Mercury, Venus, Earth, & Mars The larger outer planets called gas giants - Outer layers are composed of gases such as hydrogen and helium - Move in elliptical or oval orbits - Jupiter, Saturn, Uranus, & Neptune The Planets

19. The terrestrial planets http://solarsystem.nasa.gov/multimedia/gallery/terr_sizes.jpg The Planets

20. The gas giants http://solarsystem.jpl.nasa.gov/multimedia/gallery/gas_sizes.jpg The Planets

21. http://solarsystem.jpl.nasa.gov/multimedia/gallery/outer_orb.jpg The Planets

22. The planets to scale. The rings of the gas giants are not shown. The Planets

23. http://solarsystem.jpl.nasa.gov/multimedia/gallery/solarsys_scale.jpg (Distance between objects not to scale) The Planets

24. Earth How small are we? source: Celestia (application) (Distance between objects not to scale) The Planets

25. Earth’s Movement In Space Babylonians, Mayans, indigenous Australians used the movements of the Sun and Moon to define their days, months, seasons, and years - Developed complex ways to predict seasonal changes - Allowed ancient people to plan when to plant crops - Survival depended on this knowledge of the Earth’s movement in space Earth’s Movement In Space

26. Planets rotate on their axes as they orbit Sun Rotation: time taken for a planet to spin once on its axis - 1 rotation = 1 day Revolution: time taken to orbit the Sun once - 1 revolution = 1 year (365.25 days) The earth spins on its axis, causing alternating day and night Earth’s Movement In Space Can you predict a planet that would have long “Earth-years”? Which planets would have short days?

27. The Earth spins once on its axis in a day, and takes a year to orbit the Sun. Earth’s Movement In Space

28. As the Earth orbits the Sun, tilt causes different parts of the Earth to experience different heating effects Summer solstice  days are longest Winter solstice  days are shortest At the two equinoxes, length of day = length of night Science Focus 1: Coursebook Earth’s Movement In Space