1. Pictures for life death of solar system

2. Nebulas

3. Nebula A cloud of dust and gas Mostly hydrogen and helium gas, 2% heavier particles Dark (dust) and light (gas) Irregularly shaped, dust and gas moving around Because particles have small amount of mass there is only a weak gravitational force exerted between them

4. Stellar Events

5. A stellar event All of the following are events that could cause the formation of a star: –A nearby supernova –Collision between nebulas –Collision between parts of same nebula Provides the force and energy needed to push large amounts of dust and gas towards each other, increasing force of gravity between particles

6. Nebula Contraction

7. Nebula contraction, rotation Force of gravity increases further as: –Distance between objects decrease –Mass of the objects get larger As mass is condensed in space, it begins to rotate The spin rate increases as the mass becomes more compact Shape of nebula becomes more round

8. Proto-star

9. Protostar Matter continues to condense into a ball of gas (protostar) and a disc of gas and denser matter surrounding the protostar The gravitational forces between particles increases Pressure builds within the dense cloud Temperature rise, making particles more active, converting gas into plasma

10. Formation of planets

11. The disc surrounding the Proto-star begins to form a number of proto planets which begin to capture and collide with all nearby surrounding fragments/dust particles in disc. This act of building a planetary body is called accretion The disc begins to form slightly after the start of proto-star construction, but before the star is turned on

12. Main sequence star

13. At some point a critical amount Pressure and energy is reached inside the Protostar, which initiates nuclear fusion between hydrogen atoms A lot of energy is released as a result of fusion as light and other electromagnetic radiation is released. The sun lights up for the first time The star will stay in this stage until the main fuel for fusion (hydrogen) is almost completely used up. Outward pressure from fusion balances gravitational pressure and produces a stable star The star exists for 80% of its life in this stage

14. Red Giant Stage

15. Red Giant Occurs when almost all hydrogen has been converted to helium Helium begin to fuse into carbon in sun’s core, while remaining hydrogen continues to fuse into helium Result: expansion of star’s outer gas shell, with gases cooling as they move away from center This results in change in size and color of sun When our sun goes through this stage, it will grow enough to swallow up Mercury and burn every thing on the surface of Venus and the Earth Lasts until there is no more helium remains to fuse into carbon

16. Planetary Nebula

17. Planetary nebula The star runs out of major sources of energy for nuclear fusion Without a energy source the star loses outward pressure, begins to collapse inward The outer gas ring is no longer pulled by gravity towards the retracting center of the star, continues outward into space For a time, the hot core of the dying sun illuminates the expanding gas ring (planetary nebula) as is passes the outer planets

18. Life Choice… Supernova or White dwarf

19. Supernova

20. Depending its original size, the remains of the final collapse of the stars may trigger one last explosion The star must be much larger than our sun As the star collapses pressures within it get incredibly high and new elements are made New elements are made in the explosion As a result of the explosion, material and energy is flung out at the speed of light in all directions Material spreads to nearby nebulas, which may start a new life cycle of a star, because of the forces created by energy emitted from the supernova

21. Neutron Star

22. Neutron stars Some stars more massive than the sun, explodes in a supernova, but leave behind a ultra dense remnant called a neutron star. The force of gravity can not break the subatomic particles down any further Remnant is composed only of neutrons, protons squeezed together (no void in atoms) Extremely dense: 1 sugar cube of a neutron star has the same weight as 1000 battleships

23. White Dwarf

24. White dwarf Those dying stars that are not large enough to go supernova, form a white dwarf Final size is much smaller than the original, some no larger than the earth Very dense Still emitting energy from release of heat, electromagnetic radiation (looks white and shiny)

25. Black Dwarf

26. Life choice: Neutron star or Black Hole

27. Black Dwarf Final death stage of smaller stars The remnants of the collapsed star with no energy left Does not emit light, providing its lack of color Could you walk on a black dwarf?

28. Black Hole

29. Results from explosions of extremely large stars The core that remains after explosion is massive enough to continue to break down the subatomic particles of matter that make it up Forms a gravitational singularity that is very small and continues to pull matter and light into it

30. What do you think is meant by a red dwarf in space?

31. Suns come in different sizes Depends on the size of the original nebula or amount of material The larger the sun, the smaller its life span (rate at which fuel is used) –Yellow stars like our sun, live about 10 billion years –Large ones, only a couple of hundred million years or less

32. Our sun is an average size Smaller stars are more common Red Dwarfs have no more than 40% of the mass of our sun Small stars can live for very long, possibly up to a trillion years Not a stage of the lifecycle, but a class of star

33. Star color Strong indication of the surface temperature of the star Blue is hottest White Yellow is medium Orange Red means lower temps

34. Star classification Russell-Hertzsprung diagram Classified by color, brightness (luminosity)

36. The fate of Big Stars Explode Core collapses to a neutron star or a black hole Bigger the core, more likely it makes a hole Holes are made because there is infinite inward force to gravity pulling towards the center of the hole.

38. Big Bang Start of the present version of the universe Occurred 15 billion years ago 300,000 years from start of BB, first atoms appear 1 billion years after BB, first protogalaxies/stars form (quasars) Astronomers have located Quasars that are 12 billion lights-years away

39. Galaxy Galaxy: Large scale groups of stars that rotate about a common axis Average galaxy is 100,000 light years across and contains 100 billion stars Astronomers estimate there are between 50 billion and 1 trillion galaxies in existence More stars than grains of sand on all beaches on Earth

40. Milky way

42. Our galaxy’s name is The Milky Way 2000 light years thick Our sun is located about 30,000 light-years from the center Rotating, 1 cycle every 200 million years

43. Quasars Some of the first objects formed after the big-bang. Quasi-stellar radio source Most distant objects observed from earth Move at 90% speed of light Star like in size, bizarre in action Might be the protogalaxies

44. What is meant by fusion?

45. Fusion Combining 2 or more nuclei together to create a large atom. Also called nucleosynthesis Requires heat higher than 18 million degrees F or 10 million degrees C

46. Where can atoms of elements be created?

47. Answer Supernovas: All natural elements Big suns that do not go POP: all elements up to Iron (AT# 26) Suns like ours can make elements up through Carbon (At# 6) Tiny suns only Helium

48. Does life exist outside the Earth Limitations

49. Features of our planet that has allowed life like us to develop Benefits

50. What is the chance of intelligent life existing outside of Earth? Limitations

51. What is the chance that we will meet them? Limitations

52. Assignments Read Comic Answer questions on handout

53. 1st

55. 2nd

57. 3rd

59. 4th

61. 5th

63. 6th

65. 7th

67. 8th

69. 9a

71. 9b

73. 10b