2. OUTCOME QUESTION(S): S1-4-08: What objects make up our solar system and Universe? Vocabulary and People CoreFusionNebulaSupernova Black holeGalaxyTerrestrial

3. Our Sun 5 billion year old small star (should last 5 more) Composed of 75% hydrogen and 25% helium Elements in plasma phase ( hotter state than gas) Energy comes from a Nuclear Fusion Reaction

4. Nuclear Fusion Reaction Joining two hydrogen to create helium Releases large amount of energy Fusion = join Fission = split Sun: joining (fusion) things to release energy Power Plants: splitting (fission) things to release energy

5. There is obviously more to the Sun then “burning ball of gas”

6. Layers of the Sun: Inside Core – centre and site of nuclear fusion Outside Photosphere – cooler surface (5500 o C) sunspots, surface storms – the part we “see” Chromosphere – inner atmosphere small solar explosions (flares), large (prominences) Corona – outer atmosphere (1 million o C) charged gas particles blow outward (solar winds)

7. “Life Cycle” of a Star Birth: Stars born out of Nebulae Nebula – huge clouds of dust and gas Youth – Middle Age: Gravity collapses material into a star that begins to release energy as a main sequence (MS) star Scientists categorize MS stars according to mass: Small - last longer (billions of years) Large - brighter but short-lived (few million yrs)

8. Nebula Attracted by gravity; matter clusters together 99% hydrogen and helium 1% iron, rock and ice

9. Actually nebulae captured by NASA space telescopes

10. Small MS star – Red Dwarf Very cool temperatures of their outer gases Death: Forms a cool, dim star called a White Dwarf Fades out until it no longer emits light energy We can’t see most Red Dwarf stars – their light is too weak

11. Medium MS star – like the Sun Separated into small-med and large-med Death: Runs out of elements for fusion reaction Collapses then swells to produce a Red Giant small-med eventually fades out as white dwarf large-med explodes as a Supernova leaving behind a Neutron star “Pulsar” neutron star

12. Large MS star Extreme energy produced for a short period Extreme energy produced for a short period Fuses heavier elements (iron) after lighter ones Fuses heavier elements (iron) after lighter ones Death: Collapses then swells to a Red Supergiant Gravity collapses the largest into a Black Hole Stars are in balance: nuclear fusion explodes outwards, large gravitational force collapses inwards When the reactor runs out of elements to fuse, gravity wins and the star collapses and (sometimes) explodes

13. Nebulae main sequence (MS) star Red Dwarf White Dwarf Red Giant Supernova Neutron star Red Supergiant Black Hole Smallest Largest Medium Birth: Death: There is still more to this puzzle, but…this is close enough

15. Galaxies Huge collections of gas, dust and billions of stars and planets (collected by gravity) Constantly in motion Many shapes: spiral, elliptical, and irregular

16. Milky Way Galaxy Contains 400 billion stars Disc-shaped, with spiral arms – spiral galaxy We are on one of the arms Has a thicker Central Bulge Rotates around the bulge New evidence suggests the “central bulge” is actually a SUPER-MASSIVE BLACK HOLE!

17. Outer region of nebula: Gases (far from forming Sun) begin to cool Cluster together and condense Forming the Gas Giants: Jupiter, Saturn, Uranus and Neptune Formation of our Solar System Matter recycled from past supernova explosions Gas Giants appear to lack solid surfaces, but the gases may become liquid or solid deeper towards their dense core

18. Inner region of nebula: Gases in the inner region too hot to condense Chunks of iron and rock collide and stick together Forming Terrestrial Planets: Mercury, Venus, Earth and Mars Terrestrial planets are composed of rock, iron and hard elements through to the molten core

20. CAN YOU ANSWER THESE QUESTIONS? S1-4-08: What objects make up our solar system and Universe? Vocabulary and People CoreFusionNebulaSupernova Black holeGalaxyTerrestrial