L.O: I will be able to Describe
the moon and its effects on the Earth�
Do Now: take out your reference table. Open your review packet
The moon is Earth’s only natural satellite.
The Moon is the only other “world” that humans have walked on so far!
The moon revolves around Earth.�just like Earth revolves around the SUN!
The moon takes 29 days to complete one revolution around Earth ( a sidereal month)
What do you notice about the Moon?
the Moon has phases because it revolves around the Earth..
Full moon
quarter moon
crescent moon
new moon
gibbous moon
the Sun’s light rays are always illuminating one half of the Moon. That is why some parts look bright & other parts look dark.
As the Moon revolves around Earth, an Earth observer sees varying amounts of the illuminated portion of the Moon.
The Moon takes 29 days to complete a phase cycle from one new moon to the next new moon.(called a synodic or lunar month)
This is the way the Moon looks as seen from Earth is different from how it is seen from space.
On the Regents you must be able to determine each phase of the Moon as viewed from space.
Appearance:
How much of the moon we see depends on where the moon is in its orbit:
Appearance:
Appearance:
The appearance of the moon at position E:
Appearance of the moon at position C:
Appearance of the Moon at position A:
Appearance of the Moon at position D
The moon’s apparent size changes because as it revolves around Earth because its orbit is elipitical
Sometimes the moon looks larger because it is a little closer to earth.
Sometime smaller when it is further.�
Tides and eclipses:
What do you notice the water is doing?
High tide and low tide
A tide is a rise in the Earth’s water levels caused by the pull of Moon’s gravity and the Sun’s gravity.
This is the same location at high tide and low tide
Spring tides and Neap tides:
Spring tides: when the Sun and Moon’s gravities pull TOGETHER on Earth’s oceans.
Spring tides happen at the FULL moon or the NEW moon, when the Sun and Moon pull together
Spring tides have the HIGHEST HIGH TIDES and the LOWEST TIDES.
Neap tides: when the Sun and Moon’s gravities pull at 90 degree
Note: Waves are NOT tides. Tides are caused by the Sun and Moon’s gravities. Waves & ocean currents are caused by the wind!
The tides are cyclical & predictable
a high tide happens every: 12.5 hours (~12 hours and 30 minutes)
*** one high tide to another high tide is ~ 12.5 hours.
Example: if a high tide happened at 10:00 AM, the next high tide is at 10:30 PM (12 and a half hours later!)
What do you notice these pictures have in common?
Shadows!
Do you think celestial objects like the Earth & Moon can cast shadows?
What do you notice?
A solar eclipse
What do you notice?
A lunar eclipse!
What is an “eclipse”?
Objects like the Earth and Moon cast shadows when the block sunlight.
An “eclipse”: when the Moon or the Earth blocks the Sun, causing a shadow to be casted.
There are two kinds of eclipses: solar eclipse and lunar eclipse.
Solar eclipse: the moon gets between the Sun and the Earth.
The Moon blocks the sunlight casting a its shadow on Earth
Solar eclipses happen during the day and are only possible during the new moon phase.
Lunar eclipse: the Earth is between the Sun and Moon. Earth blocks the sunlight and casts a shadow on the moon.
Lunar eclipses only happen at night, during a full moon!
Eclipses can only be seen over certain parts of the earth
Eclipses can only be seen over certain parts of the earth
Total eclipses and partial eclipses
Since the renaissance we have learned that most celestial motions, INCLUDING eclipses are cyclical and predictable.
Eclipses are rare because the Moon, Earth & Sun must be aligned.
Usually the Moon, Earth & Sun are NOT aligned, the plane of the Moon’s orbit is usually 5 degrees above Earth’s orbit
Independent work: complete the odd questions of 2010 Regent
Homework:
Complete the even questions