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2012-01-26 17:34:03
astronomy exam

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  1. reason for days
    the earth rotates once everyv24 hoursto give us nights and days
  2. reasons for months
    the moon revolves around the earth every 29 days giving us one month
  3. reasons for years
    the earth revolves around the sun every 365 daysgiving us 1 year
  4. the reasons for seasons
  5. how are tides caused?
    by the tug and pull of the moons gravity
  6. what is a solar eclipse
    sun > moon > earth
  7. what is a lunar eclipse
    sun> earth > moon
  8. what is retrograde motion?
    • example using earth and mars
    • when we approch mars in space it looks like it's slowing down
    • when we pass it, it seems like it is going backwards
  9. the geocentric model

    • by aristotle
    • the earliest to imagine
    • the universe was a gigantic sphere with the earth at the center
    • it could not explain retrograde motion
  10. what is the heliocentric model

    • by nicholas copernicus
    • made in the early 1500
    • the sun was at the center of the model
    • and all other planets rotated around the sun on the same solar plane
  11. what is the order of the planets
    • My Very Excellent Mother Just Served Us Nine Pizzas
    • mercury
    • venus
    • earth
    • mars
    • jupiter
    • saturn
    • urans
    • neptune
    • pluto
  12. discription of mercury
    iron richs core and rocky
  13. description of venus
    has green house effect cloud covered
  14. description of earth
    life and oxygen
  15. description of mars
    red dry river beds
  16. description of jupiter
    • narrow dust rings LARGE
    • gas
  17. description of saturn
    yellow wide rings, gas
  18. description of urans
    rings blue gas
  19. descriptions of neptune
    giant dark spot, rings,blue,gas
  20. description of pluto
    • dwraf planet
    • tiny, orbit not in the solar plane
  21. the solar nebula theory
    • 1) spaces between stars filled with gas and dust, mostly hydrogen
    • 2) gravity pulls the dust and everything else to the middle
    • 3) cloud spins faster and faster more hydrogen builds up in the center
    • 4)large build up of gas in the centerwill become a star, the cloud flattens into a disk due to spinning
    • 5) little pockets of gas accumulate and spin in the same direction as the cloud, planets will form as gases in the center compress. The temperature rises to 10 000 000 the star will light
    • 6) solar winds from the new star blow away most of the hydrogen and helium from the inner reigons leaving chunks of heavy matter chunks grow in size becoming planets remaining planets become astroides and comets
  22. life cycle of a star
    • 1)are formed inside massive clouds of dust and gas called nebula
    • 2)gravity pulls everything into a shrinking ball
    • the ball gets smaller and hotter
    • 3) when the temperature hits 10 million degrees nuclear fusion begbegins
    • the H combine with the He
    • 4) hot material pushes out while the gravity pulls it back in
    • when the forces become equal it is a main sequence star
  23. what is a galaxy?
    a huge collection of gas and dust with 100 billions of stars
  24. what is the milky way?
    400 billion of stars sprial galaxy
  25. what are elliptical galaxies?
    • foot ball shaped
    • made of young stars and gas clouds
  26. what are sprial gallaxies?
    • young stars two types of galaxies
    • spiral= round center
    • barred= spiral bar center
  27. what are irregular galaxies?
    have no shape
  28. meteors
    dust and rocks when objects are burning genorating light to make it visible they are called meteors
  29. meteorites
    the meteors that are large enough to come in the earth
  30. what state is our sun in now?
    it is a main sequence star
  31. what are comets?
    mainly dust and ice while they orbit around the sun the material evaporates forming the tail
  32. what are astroides?
    minor planets, metal rich materials
  33. what is a intermediate mass star?
    • called red giant
    • runs out of H in 10 billion years
    • outer surface expands 100 times
  34. what are low mass stars
    • red dwarf
    • less gravatational pressure
    • doesn't consume H
    • ho material escapeseasily after 100 billion years
  35. what are massive stars?
    have more gravatational pressues consume hydrogen faster and quicker when fules run out it explodes into a super nova