Study Guide Astronomy test 1

  • The heliocentric model states that the Sun is the center of the solar system and the planets and other objects of the solar system revolve around it.
  • The first person to propose the heliocentric model of the solar system was Aristarchus
  • Copernicus was the astronomer who proposed the heliocentric model after the middle ages
  • Kepler’s first law of motion states that the planets orbit the Sun o=in elliptical orbits.
  • Newton is the scientist formulate the Law of Universal Gravitation
  • The Earth’s motion in its path around the Sun is its revolution
  • Precession is the slow change in the direction in which Earth’s axis tilts
  • The moon goes through a complete phase cycle every 29.5 days
  • A solar eclipse occurs when the moon casts a dark shadow on to Earth
  • During a total lunar eclipse the moon moves into Earth’s umbra (the darkest part of a shadow)
  • The rocks on the moon are moved and broken down on the moon by impacts of particles from space
  • The most accepted theory of the moon’s formation is the giant impact theory a large body struck Earth shattering and the resulting debris coalesced to form the moon
  • The oldest features on the moon are the highlands.
  • The largest of the terrestrial planets is Earth.
  • The density of the Jovian planets is not more than 1.5 times the density of water (they have low densities)
  • The formation of the solar system comes from a rotating disk of dust and gas that forms the Sun then the planets.
  • The diameters of the Jovian planets are much larger than the terrestrial planets.
  • Because Mercury has no atmosphere it reflects a small percentage of the sunlight that strikes it.
  • Life as we know cannot exist on Venus because the surface temperature is too hot.
  • Mars will appear to change color because dust storms can last for weeks causing the atmosphere to change color.
  • The mass of Jupiter is 2.5 times the mass of all the other planets and their moons combined.
  • Rings are found at all of the outer planets Jupiter, Saturn Uranus, & Neptune
  • Neptune has the slowest orbital speed Mercury the fastest.
  • The asteroid belt where most asteroids are found lies between Mars and Jupiter.
  • Asteroids have recently impacted the moon creating craters
  • Comets are held together by frozen gases.
  • The Kuiper belt is the place where comets with short orbital periods are found
  • Highly elliptical orbits like comets will have eccentricities close to 1 Planets would eccentricities close to 0
  • The dating of the solar system has come from dating meteorites
  • Meteorites are leftover inter planetary debris, material from the asteroid belt and the solid remains of comets.
    Know the moon phases