1 / 40

The Sun and the Origin of the Solar System

The Sun and the Origin of the Solar System. Mid-sized, G-type main sequence star Distance: 1 AU = 150 million km away Size: Actual radius 700,000 km = 100 Earths Temperature, Luminosity (surface) T = 6000 K http://www.nasa.gov/multimedia/videogallery/index.html.

ambrose
Download Presentation

The Sun and the Origin of the Solar System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Sun and the Origin of the Solar System

  2. Mid-sized, G-type main sequence star • Distance: 1 AU = 150 million km away • Size: Actual radius 700,000 km = 100 Earths • Temperature, Luminosity (surface) T = 6000 K http://www.nasa.gov/multimedia/videogallery/index.html

  3. 99.86% of the total mass of the Solar System • 75% hydrogen, 23% heliun • 2% O, C, Ne, Fe

  4. Sunspots • surface areas that are darker than surroundings (lower temperatures) • regions of intense magnetic activity

  5. Solar Evolution

  6. Star (Sun) formation

  7. Stellar Evolution • The Sun is a middle-aged, low-mass, main-sequence star • 5 billion years ago: • Beginning of its life on main-sequence • Sun had 1/3 luminosity it has now. • 5 billion years from now: • End of its life on main-sequence • Sun will have twice the luminosity it has now.

  8. When H is exhausted, core shrinks. • Heats up • High temperatures ignites a shell of H around the core. • Increased pressure drives the envelope of the star outward. • Creates a Red giant

  9. Contraction of core, raises the temperature • Ignites He shell around the core • Eventually the core stabilizes • Envelope is ejected as a "planetary nebula" • The core remains as a "white dwarf"

  10. Solar system formation • Starting point: • A cloud of interstellar gas and dust, the "solar nebula“ • Most of it (98%) is hydrogen and helium, includes dust grains of heavier material, formed in previous generations of stars.

  11. Contraction • Accretion disk • Protostar • Condensation • Planetesimals

  12. http://www.youtube.com/watch?v=5l5mB-rFuGo

  13. Asteroid Belt • Small bodies in the inner solar system • Asteroid Belt between Mars & Jupiter. • Orbits are strongly influenced by Jupiter. • Made of rock, metal, or a mix of the two.

  14. >300,000 asteroidal objects • >150,000 with good enough orbits to give official numbers • ~15,000 asteroids with official manes • When you know its orbit, you can name it.

  15. Examples of asteroid names • Ceres (largest – 914 km) • Eros (landed on in2001 Feb 12) • Bach • Beethoven • Lennon • McCartney • Santana • Clapton

  16. Irregular shape • Too small for gravity to make them spherical

  17. Composition of Asteroids • C-type: "Carbonaceous" – mostly carbon-bearing materials. ~75% of all asteroids. • S-type: "Silicaceous" - mostly of silicates (stony or stony iron). 17% of all asteroids. • M-type: "Metallic" - probably iron-rich

  18. Asteroid Origins • fragments of larger, differentiated bodies shattered by collisions • remnants of more primordial material that never got differentiated

  19. Impact with Earth Would disrupt climates and trigger mass extinctions

  20. Meteoroids • Chunks of rock & iron smaller than asteroids orbiting the Sun • Sizes range from grains to 100 meters across

  21. Meteor • Streak of light when a meteoroid enters the Earth's atmosphere • Most are tiny grains • Meteor showers are trails of debris left behind by passing comets

  22. Meteorite • Any remnant that reaches the ground intact.

  23. Russian Meteorite • http://www.youtube.com/watch?v=90Omh7_I8vI

  24. Meteor Impacts • About 100 tons of meteoroids hit the Earth each day • Most are no bigger than grains of sand or smaller

  25. Earth Impact Effects Program http://impact.ese.ic.ac.uk/ImpactEffects/

  26. Comets Small bodies consisting of aggregates of ices mixed with rock & dust

  27. As they approach the Sun, they heat up and the ices sublimate (go from solid to gas):

  28. Halley's Comet • In 1705, Edmund Halley computed the orbit of the great comet of 1682 using Newton's laws • Found that orbit of 1682 comet was the same as comets seen in 1531 & 1607. • Predicted return in 1758. • Seen again on Christmas day 1758, 12 years after Halley's death

  29. Origin of Comets • Short-period comets are from the Kuiper Belt • Long-period comets are from the Oort Cloud

  30. Structure of Comets • Nucleus: • Dirty snowball of ices & dust • >99% the mass of the comet • Coma • Bright "head" of the comet • Low-density cloud of gas & dust sublimed off the nucleus • Extends out to 100,000 km or more

  31. Comets have two tails • Dust Tail, dusty particles swept back in a curved path by solar radiation, white • Ion Tail, ionized atoms & molecules swept straight back by the solar wind, blue

  32. Comet Orbits • Typically have a high degree of eccentricity http://www.windows2universe.org/comets/comet_model_interactive.html

  33. Kuiper Belt • Region of the Solar System beyond the planets extending from the orbit of Neptune (at 30 AU) to approximately 55 AU from the Sun

  34. Oort Cloud • Cloud of comets which may lie roughly 50,000 AU, or nearly a light-year, from the Sun. • Nearly a quarter of the distance to Proxima Centauri, the nearest star to the Sun

More Related