ASTRONOMY---PART 2 PREZI TRANSCRIPT
PREZI
The Moon
Phases, Eclipses, and Tides
Basics
Caused by the changing positions in the moon, earth, and sun cause:
Phases
Eclipses
Tides
Phases
The different shapes of the moon you see from earth
The moon is not luminous (no light source)….instead, it reflects light from the sun.
The amount of moon you see depends on how much of the sunlit side faces the earth.
Ex. New moon, the side that is “illuminated” is facing away from the earth, so it appears dark.
Waxing: When it is growing
Waning: When it is shrinking
Eclipses
When an object in space comes between the sun and a third object, it causes a shadow to cast on the object
When the moon’s shadow hits Earth or the Earth’s shadow hits the moon, eclipses occur
Solar: Sun
Lunar: Moon
Solar Eclipses
When the moon passes directly between the earth and the sun---the view of the sun is blocked from Earth
Umbra: The darkest part of the moons shadow—only during total eclipses
Penumbra: The larger part of the shadow---only during partial eclipses
Lunar Eclipses
Happens when the earth is directly between the moon and the sun.
The Earth blocks the sun….the moon’s light source.
Can also be partial or total
Tides
Review: Caused by how much gravity of the moon pulls on the oceans
Tide Cycle: 12 Hours apart
2 Each day: high & low
Spring Tide: Greatest difference between tides (New & Full Moon)
st
rd
Neap Tides: Least difference between tides---Right angles (1 and 3 Quarters)
Earth’s Moon
Maria: Flat, dark areas from lava flows
Craters: Large round pits
Caused by the impacts of meteoroids (chunks of rock and dust from space)
Highlands: Light colors of the moon
Moon Characteristics
Size: 3476 km (about the size of the US) in diameter
Moon 1/8 that of the earth
Earth’s Density is in the core
Moon has layers that are less dense like the Earth’s outer layers
Moon Temperatures vary from -180 to 130 degrees C.
Moon has no liquid water, but may have ice at the poles.
Where did it come from?
A planet sized object collided with the earth and got caught in it’s gravitational pull…..