How our Solar System (and Moon) came to be…

1. How our Solar System (and Moon) came to be…

2. Learning Objectives • Be able to explain • How our solar system and moon came to be

3. IRAS launched into orbit 1983 • Direct evidence that solid matter exists around stars • Can cloud particles be early stages in the development of the planets? • Theory emerged: Planets form while star is forming

4. Rotating Nebula Theory • Solar system began as collection of dust and gases (nebula) • This nebula made up of mainly hydrogen and helium gases • Also some solid particles like iron, rock, ice

5. These particles came from massive explosion of an older star called supernova • Supernova = star in it’s final phase of life, when it explodes it is many time it’s original size • Particles had moved closer together due to gravity

6. As nebula collapsed, internal pressure and temperature increased and more particles were attracted to nebula • Eventually temperature and pressure in the gas cloud was great enough for a complex reaction to begin

7. Reaction caused release of large amounts of energy, creating massive explosions • At core of nebula, our Sun began to develop

8. Early stages of the nebula began to rotate due to gaseous material • The speed of rotation became too great to hold al of matter togetherat center • Matter spread out from center like pancake

9. Bulge remained at center forming the Sun • While sun formed, smaller clumps of cooler matter called protoplanets began to appear in outer regions of nebula • Protoplanets condense to form planets of our solar system getting larger as they pick up debris • Likely how gas giants came to be

10. Sun flared up in a sudden burst of energy • Caused helium and hydrogen into the outer regions • Dense chunks of solid matter left behind • Formation of inner planets

12. Other bodies in Solar System • Asteroids • Rocky object, smaller than a planet that orbits the sun • They orbit the sun between Mars and Jupiter (asteroid belt) • Asteroids often collide and break into pieces called meteoroids • “Falling stars” are meteoroids becoming meteorites as they pass into earth’s atmosphere

13. Meteors and Meteorites • Meteor – lump of rock or metal that falls from space towards earth’s surface • Meteorite – a meteor that is large enough to survive entry and reach the surface of the earth • Separated into 2 broad groups: stones and irons • Impact of meteorite creates a crater

14. Comets: • Usually name after their discoverers • Are made of rock dust and icy matter left over from the formation of the solar system • Ancients believed comets to be the soul of a hero or king on its way to heaven or messengers of disasters • Gas pushed out behind nucleus (Tail) • Nucleus (rocky and metallic particles coated with H20, ammonia, methane and CO2 • Come – formed as frozen substances begin to vapourize

16. Formation of our Moon • Moon about 4.5 billion years old…. Similar in age to the Earth • How?? Why??

17. Big Splash Theory • Large object (size of Mars) collided with Earth • Collision caused high temperatures and pressures • This ended up in materials like iron to become part of Earth’s core

18. Less dense materials blasted into space • Ended up orbiting around the Earth • Materials began to condense and gravitate into each other through more heat and pressure