Solar System Formation: Nebular Hypothesis and Planetary Groups

1. Open up a word document Title it: 2/02 Weekly Notes Put a ✔ by your name Weekly Notes

2. Formation & The Members of our Solar System Astronomy 101

3. Solar System Formation Scientists believe that the solar system was formed when a cloud of gas and dustin space was disturbed, maybe by the explosion of a nearby star (called asupernova). This explosion made waves in space which squeezed the cloud of gas and dust.

4. Solar System Formation Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula. Just like a dancer that spins faster as she pulls in her arms, the cloud began to spinas it collapsed.

5. Solar System Formation • Eventually, the cloud grew hotter and denser in the center, with a disk of gas and dust surrounding it that was hot in the center but cool at the edges.

6. Solar System Formation • As the disk got thinner and thinner, particlesbegan to stick together and form clumps. Some clumps got bigger, as particles and small clumps stuck to them, eventually forming planets or moons.

9. Solar System Formation Near the center of the cloud, where planets like Earth formed, only rocky material could stand the great heat.

10. Solar System Formation Icy matter settled in the outer regions of the disk along with rocky material, where the giant planets like Jupiter formed.

11. Solar System Formation As the cloud continued to fall in, the center eventually got so hot that it became a star, the Sun, and blew most of the gas and dust of the new solar system with a strong stellar wind. By studying meteorites, which are thought to be left over from this early phase of the solar system, scientists have found that the solar system is about 4600 million years old!

12. Stephen Hawking: Formation of the Solar System • http://www.youtube.com/watch?v=Uhy1fucSRQI

13. Nebular Hypothesis • Nebular hypothesis • Planets formed about 5 billion years ago • Solar system condensed from a gaseous nebula

14. Nebular Hypothesis (cont…) • As the planets formed, the materials that compose them separated • Dense metallic elements (iron and nickel) sank toward their centers • Lighter elements (silicate minerals, oxygen, hydrogen) migrated toward their surfaces • Process called chemical differentiation

15. Nebular Hypothesis (cont…) • Due to their surface gravities, Venus and Earth retained atmospheric gases • Due to frigid temperatures, the Jovian planets contain a high percentage of ices

16. The Nine Planets • The planets of our solar system can be broken into three groups • Terrestrial (Earth-like) • Jovian (Gaseous) • Pluto

17. The Terrestrial Planets • Terrestrial (Earth-like) planets • Mercury through Mars • Small, dense, rocky • Low escape velocities

18. Mercury • Innermost planet • Second smallest planet • No atmosphere • Cratered highlands • Vast, smooth terrains • Very dense • Revolves quickly: 88 Earth Days in 1 Year • Rotates slowly: 59 Earth Days in 1 Day

19. Venus • Second to the Moon in brilliance • Similar to Earth in • Size • Density • Shrouded in thick clouds • 1 Venusian Day is 244 Earth Days • 1 Venusian year is 225 Earth Days • Nickname: Veiled Planet

20. Venus - Surface

21. Venus from Clementine

22. Earth • Nick-named the“Blue Planet” because of the blue color it seems to have from outer space. • Only planet known to have life.

24. Earth’s Moon • Known as “Luna” • Diameter of 3475 kilometers is unusually large compared to its parent planet • No atmosphere • Hypothesis suggests that a giant asteroid collided with Earth to produce the Moon

26. Mars • Called the "Red Planet" • Atmosphere • 1% as dense as Earth's • Surface • Numerous large volcanoes – largest is Mons Olympus • Several canyons • Moons • Two moons • Phobos • Deimos • Captured asteroids

27. Mars

28. Valles Marineris

29. Olympus Mons

30. Jovian (Jupiter-like) planets • Jupiter through Neptune • Large, low density, gaseous • Massive • Thick atmospheres composed of • Hydrogen • Helium • Methane • Ammonia • High escape velocities

31. Jupiter • Largest planet • Nickname: Lord of the Heavens • Very massive • Rapid rotation • Banded appearance • Great Red Spot • At least 28 moons • Ring system

32. Great Red Spot

33. Jupiter’s Rings and Small Moons

34. Galilean Satellites • Callisto • Europa • Considered to be a likely location for extraterrestrial life. • Ganymede • Io

35. Jupiter’s Magnetic Field

36. Saturn • Nicknamed “ElegantPlanet” • Similar to Jupiter • Most prominent feature are the rings • Thirty named moons • Titan – the largest Saturnian moon

37. Saturn’s Rings – mostly ice

38. Titan – a moon of Saturn

39. Uranus • Uranus and Neptune are nearly twins • AKA: The Sideways Planet • Rotates "on its side" • Rings • Large moons have varied terrains

40. Neptune • Dynamic atmosphere • One of the windiest places in the solar system • Great Dark Spot • White cirrus-like clouds above the main cloud deck • Eight satellites • Triton – largest Neptune moon

41. Pluto • Not visible with the unaided eye • Discovered in 1930 • Highly elongated orbit causes it to occasionally travel inside the orbit of Neptune, where it resided from 1979 thru February 1999 • Moon (Charon) discovered in 1978 • Average temperature is -210C

42. Pluto (seen from Charon)

43. How Big is Pluto ?

44. Minor members of the solar system

45. Planet Brochure Project • Use the Planet Brochure Template (posted in Moodle) • All of the facts and information that needs to go in your Planet Brochure, is on the Template • Website: • http://solarsystem.nasa.gov/planets/index.cfm • Due: When thinking about what to suggest that the travelers take with them on the trip and how they will survive consider the following questions... • What are the conditions that humans need to live? • What is the planets temperature? • What is the quality of the atmosphere of the planet? • What other conditions on the planet are harmful to humans? • What are the surroundings of the planet like? • How would humans navigate the planet? • Inside what kind of vessel or hotel would humans best stay--remember you must consider what the surface of the                                                  planet is made of.