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Astro test

  1. Definintion of science
    1. Systematic study of the world

    2. A way of knowing about the physical world
  2. Characteristics of science
    • - empirical data
    • - provisional explanation
    • - specific to general
  3. Siderdal day
    360 rotation of the earth
  4. Solar day
    day measured from the sun
  5. Differences between siderdal day and solar day
    • - earth is always orbiting the sun
    • - solar day is longer than siderdal day (1/365th)
    • - earth rotates one degree in a siderdal day
  6. Celestial sphere
    crystal that embeds the stars
  7. celestial equator
    great circle that lies between north and south of celestial poles
  8. Celestial horizon
    great circle that divides visible stars from non visible stars
  9. Celestial meridian
    divides east and west runs north south through observers zenith
  10. Three ways to locate stars
    • - constellations
    • - declination
    • - azimath and altitude
  11. Declination
    angle between point on celestial sphere and equator.
  12. Altitude
    • - angle above horizon
    • - always less than 90 degrees
  13. Sideral period
    moons 360 degree rotation around the earth in 27.3 days
  14. Synodic period
    repeat set of moon phases in 29.5 days
  15. Cause of moon phases
    • - position of moon earth and sun
    • - we can only see a portion of the moon when lit
  16. Solar eclipse
    • - sun's light is blacked by the moon
    • - need a new moon and ecliptic
  17. Lunar eclipse
    • - sun's light on moon is blocked by earth
    • - need a full moon and ecliptic
  18. Eratoshenes
    discovered the earth was a circle
  19. Retrograde motion
    planets moving from east to west ; Mars, Jupiter, Saturn
  20. Great astronomers
    • - Aristorchus (sun centered)
    • - Aristotle (earth centered)
    • - Hipparahus (invented epicycles)
    • - Ptolemy (used epicycles)
    • - Copernicus (heliocentric model; retrograde motion at opposition)
    • - Brahe (produced accurate data)
    • - Kepler
    • - Galileo
    • - Newton
  21. Kepler laws
    • - planets move in elliptical with sun at focus
    • - line joining sun and planet sweeps out equal areas in equal time
    • - sideral period squared=cube of distance to sun
  22. Galileo
    • - found sun spots
    • - saw Venus phases
    • - moons orbiting Jupiter
  23. Newton's law of motion
    • - body at rest will go in straight line
    • - rate of change of velocity=mass of body being accelerated
    • - force a exerts on force b; b exerts equal and opposite force on a
  24. Newton's law of universal gravitation
    • - mass attracts other mass in the universe
    • - force of one mass exerts on another=mass of two bits and is inversely proportional to the distance between them
Author
pricera
ID
41074
Card Set
Astro test
Description
Basic Astronomy
Updated

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