science exam

• The sun is the center of our solar system.
• Our sun is a medium sized star, currently in the main sequence stage.
• Diameter of the sun is 1,400, 000 km
• Distance away from earth: 149,600,000 km away
• Temperature at the center (core): 15,000,000 degrees C
• The sun has two primary gases:

  • hydrogen - 75%
  • helium - 24%
  • other gases - 1%
• Sun's innermost layer is the core, which is the hottest part of the Sun being 15M ℃
• Radiative zone - One of the inner layers of sun, being a passageway for all the energy released at the core (7-12M ℃)
• Convection zone - outermost layer of the inner layer (2M ℃)
• Photosphere - a outer part of the sun with a glowing layer of gases on the sun's surface (visible layer)
• Chromosphere - layer above photosphere
• Corona - outer layer of the sun
• Sunspots - dark areas found in the photosphere, are darker because they have a cooler temperature than the rest of the sun.
• Solar flares - explosions of magnetic energy from the corona into space
• Solar prominences - loop like explosions
• The Earth is 4.54 billion years old.
• Earth's average distance from the sun is 150M km.
• The Inner core has the following:

  • solid, hot, and dense ball of (mostly) iron
  • radius: 1220km
  • temperature: 5200℃
  • pressure: 3.6M atm (atmosphere)
• The Outer core has the following:

  • mostly composed of liquid iron and nickel
  • thickness: about 2200 km - 2250 km
  • temperature: 4500 ℃ to 5500 ℃
• mantle:

  • makes up most of the Earth’s interior
  • the layer of molten rock between the solid crust and the hot, dense core
  • thickness: about 2900 km
  • temperature: 1000 ℃ to 3700 ℃
• crust:

  • outermost layer
  • makes up 1% of theEarth’s mass
  • made up of solidrocks and minerals
  • continental crust -older, thicker
  • oceanic crust -younger, denser
• The moon is only 1/4 the size of earth.
• Distance of the moon from earth: 384,000 km
• The moon rotates at the same rate it revolves around the earth. This is called synchronous rotation.
• Our moon makes a complete orbit around the earth in 27 days.
• • Because Earth is moving as well – rotating on its axis as it orbits the Sun – from our perspective, the Moon appears to orbit us every 29 days.
• Surface of the moon:

  • solid, rocky surface (cratered and pitted from impacts by asteroids)
  • has a thin and negligible atmosphere (exosphere)
  • Temperature: 127 ℃ facing the sun, -173 ℃ away from the sun
• Lunar regolith - charcoal-gray, powdery dust, and rocky debris
• Surface of the moon:

  • highlands - light areas of the moon
  • maria (or mare; Latin for seas) - dark features; impact basins filled with lava between 4.2 and 1.2 billion years ago.
• Layers of the moon:

  • crust - outermost layer consisting of dusty outer rocky layer called regolith
  • mantle - divided into two: the rigid lithosphere (upper mantle) and athenosphere (lower mantle which is hot enough to flowcore - innermost layer;
  • The inner core is a solid,iron-rich part (240 km thick) surrounded by a liquid iron core (90 km thick). This, in turn, is surrounded by a partially molten layer.