Astronomy - 6.E.1
Phases of the Moon
Waxing = Illumination increases
Waning = Illumination decreases
Crescent = Moon is less than 1/2
Gibbous = Moon is more than 1/2
Length of Lunar Cycle
It takes 29.5 days,The moon completes its orbit around the earth in 27.3 days.
Tides
Spring : A tide just after a new or full moon, when there is the greatest difference between high and low water.
Neap: A tide just after a new or full moon, when there is the greatest difference between high and low water.
Diurnal: One low tide and one high tide
Semidiurnal: Two low and high tides
Eclipses
Lunar eclipses occur when Earth's shadow blocks the sun's light.
A solar eclipse is a type of eclipse that occurs when the Moon passes between the Sun and Earth.
The outer part of the moon's shadow is called the penumbra.
The inner part of the shadow is called the umbra.
Seasons
Revolution and Rotation
It takes earth 365 days (year) revolve.
Earth rotates on its axis, one day on earth is one rotation of the earth.
Tilt on Axis
Due to the tilt of earth as it travels around the sun we have seasons.
Why is a Year a Year
A Earth year is the time it takes the earth to make one orbit of the sun. The Earth's orbit around the Sun takes 365.24 days.
Northern Hemisphere
The Northern Hemisphere is the half of Earth on the north of the eqautor.
Southern Hemisphere
The Southern Hemisphere is the half of earth on the south of the eqautor.
Eqautor
The eqautor is an imaginary line dividing earth creating the Northern Hemisphere and the Soutern Hemisphere