Science CH 25-26

  1. 3 Ways the Earth could have formed
    Earth was spinning so quickly that a chunk spun off and fell into Earth's orbit

    Formed simultaneously

    Formed elsewhere and got caught in Earth's orbit
  2. The Impact Theory
    A planet-sized object hit Earth, formed a ring, and then the things in the ring combined and fell into Earth's orbit
  3. Meteoroid
    a celestial body (as small as a speck as large as large...)
  4. Craters
    depressions from the impact of a meteor/ite
  5. Micrometeoroids
    no larger than sand grains

    allowed by lack of an atmosphere

    major cause of erosion on the moon
  6. Why do we only see one side of the moon?
    (59% because of wobble)

    on axis same period as 1 orbit around Earth
  7. Moon measurements
    • Diameter = 3476 km
    • 1/4 Earth's

    • Density = 3.3 g/cc
    • Earth is 5.5 g/cc

    Mass = 1/18 Earth's
  8. Moon Layers
    • Iron core
    • Partially molten region
    • Rigid Lithosphere (1,000 km thick)
    • Near side crust (65 km thick) Far side crust (150 km thick)
  9. Maria
    • means "seas" in Latin
    • thought basins were filled with water
  10. Lunar Highlands
    light areas

    rugged mountains pockmarked with craters
  11. Dark Areas
    great basins and level plains formed when lava spewed up to the surface through factured caused by earlier giant impacts
  12. Mare Basalts
    • fine-grained crystalline rocks
    • younger lunar rocks
    • 3.1-3.8 billion years old
  13. Mascons
    • higher areas of gravity
    • short for "mass concentrations"
  14. Rille
    • Trenchlick valleys running in Maria Bedrock
    • Hadley Rille in Mare Imbrium
  15. Breccia
    rocks made of angular fragments cemented together with fine material

    • Earth- formed by volcanic eruptions
    • Moon- formed by meteoroids impacts that melted rocks together
  16. Rays
    • come out of craters
    • consist of shattered rocks and dust from the impact
  17. Regolith
    • loose rock material
    • grayoish brown mixture of fine particles and small rocks
  18. Moon's Orbit
    • Rises in the east, sets in the west
    • 27 1/3 days to orbit
    • Rises above the horizon at a different time each day
    • the moon moves 13. eastward along it's orbit so Earth must rotate 13. each day
    • Moon rises and sets about 50 minutes later each day
  19. Perigee
    the moon closest to Earth
  20. Apogee
    the moon when it is farthest from Earth
  21. Moon Phases
    • 1. New Moon
    • 2. Waxing Crescent
    • 3. First Quarter
    • 4. Waxing Gibbous
    • 5. Full Moon
    • 6. Waning Gibbous
    • 7. Last Quarter
    • 8. Waning Crescent
  22. Waxing
    looks bigger
  23. Waning
    looks smaller
  24. Umbra
    area of total shadow
  25. Penumbra
    are of a partial shadow surronding the umbra
  26. Lunar Eclipse
    • The moon is fully within Earth's umbra
    • 1 per year

    Sun Earth Moon
  27. Total Solar Eclipse
    • New Moon Phase
    • 1 per year
    • The moon's umbra reaches Earth
    • Perigee

    Sun Moon Earth
  28. Partial Solar Eclipse
    • The moon's umbra goes just above the Earth
    • The moon's penumbra skims the top of the Earth
    • Perigee

    Sun Moon Earth
  29. Annular Eclipse
    • The moon's umbra does not reach the Earth, but it's penumbra does
    • Apogee

    Sun Moon Earth
  30. Fusion
    nuclei combining of lighter elements to form a heavier element

    Hydrogen & Helium
  31. Plasma
    4th State of Matter

    • Charged particles (nuclie or ions) with a positive electric charge and electrons, which have a negative charge
    • They usually repel each other, but due to their speed, they fuse

    Hydrogen & Helium
  32. Layers of the Sun
    • Core 15.6 mil
    • Radiative Zone 8 mil
    • Convection Zone 1.5-2 mil
    • Photosphere 6,000
    • Chromosphere 20,000
    • Corona 1 mil
  33. Core
    Hydrogen and Helium ions in a plasma state
  34. Radiative and Convection Zones
    • Radiative-
    • plasma, but cooler than the core

    • Convection-
    • rising and falling currents of plasma
    • carry energy to the Sun's surface where it is radiated out into space as sunlight
  35. Photosphere
    inc granules
    visible surface of the sun

    • Granules-
    • formed by tops of the currents
    • lasts about 20 min
  36. Chromosphere
    inner layer of the sun's atmosphere
  37. Solar Prominence
    • from one sunspot to another
    • like an arch
  38. Corona
    • thin outer atmosphere
    • a million times less bright than the photosphere
  39. Sun's Distances from Earth
    • 1 AU
    • 150 million km
    • 93 million mi
  40. Sunspots
    • dark spots on the photosphere
    • sunspot cycle- peak every 11 years
    • proved that the sun does rotate?
  41. Solar Wind
    • constant stream of electrically charged particles given off by the corona
    • deflected by Earth's magnetic field
  42. Coronal Holes
    solar wind comes out of coronal holes
  43. Solar Flares
    outbursts of light
  44. Auroras
    • the particles of solar wind interacting with Earth's atmosphere
    • only show in the north and south poles because the magnetic field goes in there
  45. Geocentric
    the Earth is the center of the universe
  46. Retrograde Motion
    when Earth catches up to another planet and goes past it, so it appears that the other planet is going backwards
  47. Ptolemy
    inc epicycles & deferent
    • puzzled by retrograde motion
    • epicycles- circular orbits
    • deferent- larger circular orbit
  48. Copernicus
    inc heliocentric
    sun is the center of our solar system
  49. Kepler's Planetary Motion Laws
    • 1. Elliptical (not completely round) orbits
    • 2. Equal Area Law
    • -the closer to the sun, the faster it's orbit
    • 3. Harmonic Law
    • -P2=D3
  50. Gravity Law
    every mass exerts a force of attraction on every other mass, and the strength of that force is proportional to the masses and inversely proportional to the disrance between them

    Isaac Newton
Card Set
Science CH 25-26
Science Chapters 25-26