1. Origin of our Universe:
Life of Stars

2. A star's color tells us how hot or cold it is.
STARS: a self-luminous celestial body of gas of which produces energy by means of nuclear fusion reactions.
A star's color tells us how hot or cold it is.
Red stars are not as hot as blue stars.
Our sun is a yellow star.
That makes it one of the cooler stars.

3. Stars Brightness A stars brightness is dependent on 3 factors
Temperature
Size
Distance from
the Earth

5. 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

6. 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

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

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

9. “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)

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

11. Actually nebulae captured by NASA space telescopes

12. We can’t see most Red Dwarf stars – their light is too weak
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

13. 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

14. Extreme energy produced for a short period
Large MS star
Extreme energy produced for a short period
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

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

16. What do you notice?

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

18. Contains 400 billion stars
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!

19. CAN YOU ANSWER THESE QUESTIONS? S1-4-08:
How do star create energy?
What objects make up our solar system and Universe?
Vocabulary & Concepts 
Core Fusion Nebula Supernova
Black hole Galaxy

20. Origin of our Universe:
Planets and Things

21. OUTCOME QUESTION(S): S1-4-08: Vocabulary & Concepts
What objects make up our solar system and Universe?
Vocabulary & Concepts 
Asteroid belt Kuiper belt Moon
Asteroid Meteoroid Meteor
Meteorite Comet

22. Jupiter, Saturn, Uranus and Neptune
Formation of our Solar System
All matter recycled from past supernova explosions
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
Gas Giants appear to lack solid surfaces, but the gases may become liquid or solid deeper towards their dense core

23. Mercury, Venus, Earth and Mars
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 have a surface of rock, iron and hard elements through to the molten core

24. Terrestrial planets

25. It rotates so slowly that its “year” is less than 2 “days” long
Mercury
Closest to the Sun
Receives sunlight 10x brighter than Earth
Day temperatures over 400°C
No atmosphere - so night temp fall to
-180°C
Day (rotation) – 59 Earth days
Year (revolution) – 88 Earth days
It rotates so slowly that its “year” is less than 2 “days” long

26. Venus 3rd brightest object in the sky
CO2 atmosphere traps heat (+ 465°C)
Many volcanoes eject tonnes of sulphur
Clouds of sulphuric acid
makes acid rain
Day (rotation) – 243 Earth days
Year (revolution) – 225 Earth days
Sun and Moon are brightest objects
Its “year” is shorter than its “day”

27. Earth Atmosphere (N2, O2, H2O) stabilizes temperature
Ranges from -85oC to +65oC
Liquid water covers about 70% of surface
Generally stable – some volcanoes, earthquakes
Day (rotation) – 1 Earth days
Year (revolution) – 365 1/4 Earth days
Distance from the Sun is most responsible for the factors that contribute to Earth’s ability to sustain life

28. Mars Bright red - iron oxide dirt makes it reddish
Most studied planet (no signs of life… yet )
Of all planets, Mars is most like Earth
Surface temp ranges from -120oC to +30oC
Day (rotation) – 1 Earth day
Year (revolution) – 687 Earth days
Although it is dry and barren now, scientists have evidence that may point to past glaciers and liquid water

29. An Asteroid Belt separates the Terrestrial planets from the Gas Giants – maybe remains of a totally smashed older planet

30. The Gas Giants

31. Jupiter Largest of the planets (11x bigger than Earth).
Has 63 moons (2006)
Great Red Spot is a continuous hurricane
Temp around -160oC
Day (rotation) – 10 Earth hours
Year (revolution) – 11.9 Earth years
The coloured bands are gas clouds being streaked over the surface as it rotates quickly

32. Saturn 2nd largest of the planets
3 moons and a shadow in this picture
2nd largest of the planets
Least dense – may not have a solid core
Rings stretch from Earth to Moon
60 moons and 1000 rings (could be crushed moon)
Day (rotation) – 11 Earth hours
Year (revolution) – 29.5 Earth years
Notice the coloured bands on the surface here too

33. It is now pronounced “ur-an-is” not “ur-anus”
Rotates on its side
Extremely cold -210oC
Has several narrow, dark rings
Has 27 moons
Day (rotation) – 17 Earth hours
Year (revolution) – 84 Earth years
It is now pronounced “ur-an-is” not “ur-anus”

34. Neptune has some faint rings too, and 20 moons
Only discovered because its gravity “tugs” on Uranus’s orbit causing changes
Blue and white – methane in atmosphere
The Great Dark Spot is a gigantic storm
Extremely cold -220oC
Day (rotation) – 16 Earth hours
Year (revolution) – 165 Earth years
Neptune has some faint rings too, and 20 moons

36. Pluto was reclassified as a dwarf planet in 2006
Kuiper Belt and the Oort Cloud
Contain thousands of icy and rocky objects
Kuiper Belt – Neptune to about 30 to 55 AU
Oort Cloud – from 5000 AU to AU
Pluto and Eris are the best known dwarf planets
found in Kuiper belt
Pluto was reclassified as a dwarf planet in 2006

37. Moon: Large natural object (rock/metal) that revolves around a planet – also called a satellite.
Humans have visited the moon’s surface six times between 1969 and 1972.
Planet (2006)
Known moons
Mercury
Venus
Earth 1
Mars 2
Jupiter 63
Saturn 60
Uranus 27
Neptune 13
Pluto 3

38. Asteroid belt in large gap from Mars – Jupiter
Asteroid: Chunk of rock/metal that orbits the Sun but too small to be considered a planet.
Asteroid belt in large gap from Mars – Jupiter
Largest is 1000 Km in diameter
Asteroid that crosses Earth’s path called a Trojan
Asteroids can get bumped and smashed into a new orbit and sometimes that orbit can get “close” enough to be pulled in by Earth’s gravity.

39. Meteoroid that completely burns up - meteor
Meteoroid: lump of rock that is trapped by Earth’s gravity and pulled into the atmosphere.
Falling meteoroids bump into air molecules heating up (friction) until the air glows – and the meteoroid burns up and breaks apart.
Meteoroid that completely burns up - meteor
producing a streak of light - “shooting star”
The only difference between meteoroid and asteroid is that a meteoroid is random and an asteroid orbits the Sun

40. Meteorite impact crater in Arizona
Meteorite: fragment of a meteoroid that doesn’t burn up and strikes the Earth (space rock).
Large meteorite collisions make craters
Westhawk Lake is a crater
Meteorite impact crater in Arizona

41. Halley’s comet: last seen in 1986 it has a orbit period of 76 years
Comet: chuck of ice/dust that orbits the Sun.
Most originate from the Oort cloud
Tail: passing by Sun heats trailing gas and debris then blown out by solar wind - millions of km long
Some have regular periods of revolution
Halley’s comet: last seen in 1986 it has a orbit period of 76 years

42. CAN YOU ANSWER THESE QUESTIONS? S1-4-08:
What objects make up our solar system and Universe?
Vocabulary & Concepts 
Asteroid belt Kuiper belt Moon
Asteroid Meteoroid Meteor
Meteorite Comet