Untitled Quiz

Study Notes

About the Universe

• The universe is made up of thousands of galaxies.
• Galaxies are huge groups of stars held together by gravity.

Solar System

• The Solar System consists of planets, stars, and other objects orbiting the Sun.
• The Sun is a massive, luminous sphere of hot plasma at the center of the Solar System.
• The Sun provides light, heat, and energy to the planets and other objects in orbit around it.

Planets in our Solar System

• Mercury:
  • Weighs only 38% of what you weigh on Earth.
  • Fastest orbiting planet.
  • One side can be 800°F when the other side is -280°F.
• Venus:
  • Weighs only 91% of what you weigh on Earth.
  • 90 times the pressure of Earth.
  • Rotates in the opposite direction of Earth.
• Earth:
  • 23 hours and 56 minutes = 1 Earth day (rotation).
  • 365 days = 1 Earth year (revolution).
  • Warm enough to keep most water from freezing and cold enough to keep water from boiling.
• Mars:
  • Air pressure is the same as 30 km above the Earth's surface.
  • Evidence of water existing in the past.
  • Volcanic history like Earth.
  • Tallest mountain (Olympus Mons) is 3x the size of Mt. Everest.

Outer Planets (Gas Planets or Jovian Planets)

• Jupiter:
  • Largest planet in the Solar System.
  • Great Red Spot from a storm system larger than Earth.
  • Pressure is so great it would crush a spaceship.
• Saturn:
  • 2nd largest planet in the Solar System.
  • 95 times more massive than Earth.
  • Largest rings of any planet, made of icy particles.
  • Most moons of any planet.
• Uranus:
  • Appears blue-green in color.
  • Axis of rotation is tilted 90 degrees.
  • Moons are named after Shakespearean plays and formed from broken moons.
• Neptune:
  • Discovered in 1846.
  • Visual belts of clouds.
  • Interior releases thermal energy to outer layers.

Comets, Asteroids, and Meteoroids

• Comets:
  • Cosmic snowballs of frozen gases, rock, and dust orbiting the Sun.
  • When close to the Sun, comets heat up and spew dust and gases into a giant glowing head and tail.
• Asteroids:
  • Small, rocky objects orbiting the Sun.
  • Found in the orbital path of the planets.
  • Made up of clays and metals like nickel and iron.
• Asteroid Belt:
  • Region between Mars and Jupiter where most asteroids orbit the Sun.
• Kuiper Belt:
  • Region beyond the planets and the orbit of Neptune.
  • Contains millions of icy objects, including dwarf planets Pluto and Eris.
• Oort Cloud:
  • Region beyond the Kuiper Belt containing billions of comets.
  • The outer limit of the Oort Cloud defines the outer boundary of the Solar System.
• Meteoroids:
  • Small pieces of rock or metal broken off from comets and asteroids.
  • When pulled into the Earth's atmosphere by gravity, they become meteors.
  • When meteors hit the atmosphere, they create a streak of light called a "falling star" or "shooting star".