Sun, Moon, Earth, Eclipses, Tides, Climate

• The Sun

  ● the center of the solar

  system

  ● a medium-sized star

  ● diameter: 1.4 million km

  ● distance from the Earth:

  149.6 million km away

  ● temperature at the center:

  15 million C
• Composition of Sun:

  75% Hydrogen

  24% Helium

  1% Other gases
• In which phase of the life cycle of a

  star is the sun currently in?

  Main Sequence
• photosphere - the glowing layer of gases on the sun’s surface (visible layer)
• chromosphere - layer above the photosphere
• corona - the outer layer of the sun
• Outer Layers of the sun

  ● photosphere

  ● chromosphere

  ● corona
• Inner Layers of the sun

  ● core

  ● radiative zone

  ● convection zone
• core - innermost layer; 15 million C
• radiative zone -passage for all the energy that is released at the core;

  7-12 million C
• convection zone - the outermost layer of the sun; 2 million 0C
• Sunspots

  ● dark areas found in the photosphere

  ● appear dark because they are cooler than the rest of the sun
• Solar flares- stream off the sun
• Prominences- looks like loops
• Earth is approximately

  4.5 billion years old 50 million years.
• Earth's distance from the sun averages about 150 million km.
• Layers of the Earth

  ● Core (inner

  and outer)

  ● Mantle

  ● Crust
• Inner core

  ● solid, hot, dense ball

  of (mostly) iron
• Outer Core

  • mostly composed of liquid iron and nickel
• Mantle

  ● makes up most of the Earth’s interior

  ● the layer of molten rock between the solid crust and the hot, dense core
• Crust

  ● outermost layer

  ● makes up 1% of the Earth’s mass

  ● made up of solid rocks and minerals

  ● continental crust - older, thicker

  ● oceanic crust - younger, denser
• Giant Impact Theory- Theia smashed into Earth, flinging material into

  space that became the Moon.
• The Moon is rotating at the same rate that it revolves around Earth

  (called synchronous rotation).
• The moon makes one complete orbit around the Earth in 27 Earth days.
• lunar regolith - charcoal-gray, powdery dust, and rocky debris
• Surface of the Moon

  ● solid, rocky surface cratered and pitted from impacts by asteroids,

  meteorites, and comets

  ● has a very thin, negligible atmosphere called an exosphere (not

  breathable)

  ● Temperature: 127 C facing the sun, -173 C away from the sun
• highlands - light areas of the moon
• maria or mare - 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 flow)

  ● core - innermost layer
• Earth's size- 4 moons
• Rotation- an object's spinning motion about its own axis.
• Earth takes approximately 24 hours or 1 day to make one complete rotation.
• The direction of Earth’s rotation is counterclockwise. It appears the Sun rises in the East and sets in the West.
• The movement of the Earth around the Sun in a fixed path is called a revolution.
• The Earth revolves from west to east.
• The Earth completes one revolution around the Sun in one year or precisely in 365.242 (365 1/4) days.
• The Earth’s axis of rotation is tilted by 23.45 (or 23.5) degrees. This tilt causes the different seasons of the year.
• The path of the Earth moving around the Sun is called an orbit. The Earth’s orbit is elliptical.
• Solstice -refers to a day with either the longest day or the shortest
• Equinox -refers to a day with equal duration of day and night