Space Chapter 7

  1. Celestial Object
    Any object that exists in space, such as a planet, a star, or the Moon.
  2. Astronomer
    A scientist who studies astronomy, which is the study of the night sky.
  3. Revolution
    The time it takes for an object to orbit another object; Earth's revolution around the Sun is 365.24 days.
  4. Rotation
    The turning of an object abound an imaginary axis running through it.
  5. Constellation
    A group of stars that seem to form a distinctive pattern in the sky.
  6. Light-Year
    The distance that light travels in one year, about 9.5x1012km
  7. Apparent Magnitude
    The brightness of a star as seen from Earth.
  8. Asterism
    Small groups of patterns that form within a constellation.
  9. Pointer Stars
    Stars that point toward Polaris, the North Star.
  10. Circumpolar
  11. Zenith
  12. Tides
    The rising and falling of ocean waters as a result od the Moon's gravity and the Earth's gravity.
  13. Phases of the Moon
    The monthly progression of changes in the appearance of the Moon, which result from different portions of the Moon's sunlit side being visible from earth.
  14. Lunar Eclipse
    The phenomenon in which the full Moon passes into Earth's shadow.
  15. Solar Eclipse
    The phenomenon in which the shadow of the Moon falls on Earth's surface.
  16. Why do we have seasons?
    Earth rotates on a 23.5° tilt on its axis. In the summer months, the northern hemisphere is tilted toward the Sun. In the winter months, the northern hemisphere is tilted away from the Sun. The opposite happens in the southern hemisphere.
  17. Planet (include inner and outer planet)
    An object that orbits one or more stars (and is not a star itself), is spherical, and does not share it's orbit with another object.
  18. Solar System
    A group of planets that circle one or more stars.
  19. Retrograde Motion
    The movement of an object in the sky, usually a planet, from east to west, rather than in its normal motion from west to east.
  20. Astronomical Unit
    The average distance between Earth and Sun, about 150x106km.
  21. Orbital Radius
    The average distance between the Sun and an object that is orbiting the Sun.
  22. Geocentric Model
    The first model of the solar system stating that Earth is the centre of all planetary motion, with the planets and the Sun travelling in perfect circles around Earth.
  23. Heliocentric Model
    The model of the solar system that places the sun in the centre of the solar system and has the planets orbit the Sun in perfect circles.
  24. Comet
    An object composed of rocky material, ice, and gas; comes from the Kuiper Belt and Dort Cloud.
  25. Asteroid
    A small object that ranges in size from a tiny speck, like a grain of sand, to 500km wide; most asteroids originate in the asteroid belt between Mars and Jupiter.
  26. Meteoroid
    A piece of rock moving through space.
  27. Meteor
    A meteoroid that hit's Earth's atmosphere and burns up.
  28. Meteorite
    A meteoroid that is large enough to pass through Earth's atmosphere and reach the ground, without being totally burned up.
  29. Trans-Neptunian Object
    Objects that circle the Sun beyond the orbit of Neptune.
Card Set
Space Chapter 7