Tides and Eclipses
What is a Tide?
● A tide is the rise and fall of the surface
level of a body of water due to the
Moon’s and the Sun’s gravitational
pull.
High Tide
Low Tide
High Tide
Low Tide
Gravitational Pull
● Earth and the other planets are kept in orbit
around the Sun by the Sun’s gravity.
● The larger an object, the greater the force of
gravity that pulls on another object.
● The Moon’s gravity distorts the sea level so
that the sea is slightly higher on the side of
Earth closer to the Moon and also on the
side of Earth further from the moon.
High Tide
● When a location on Earth is
located so that it faces the
moon or is opposite the moon,
the bulge of water is at it’s
highest point, or HIGH TIDE.
Low Tide
● Between these two areas are
low areas because water has
been pulled away to form the
bulge. These areas experience
LOW TIDE.
Draw this on paper!
Then WATCH THIS!!
http://aspire.cosmic-ray.org/Labs/Tides/tides_simulator.html
What About The Sun?
● The sun also has an influence on
the tides. Even though the sun
is further away, it has much
more mass than the Moon.
● If the Sun and Moon are pulling
in the same direction on Earth,
when the three bodies are in
line, the tides are stronger. This
is called a SPRING TIDE.
What About The Sun?
● If the sun is pulling on Earth
at a right angle from the
moon, the tides are weaker.
This is called a NEAP TIDE.
Draw this diagram!
Spring OR Neap? Spring OR Neap?
Stop and Think-Copy these Qs into NB then answer
● If the tide is high where you are, is the
tide high or low on the side of Earth
directly opposite of you?
● If the Earth did not turn, how would
the pattern of tides be affected?
What is an Eclipse?
● An eclipse is the blocking of light from
one object in space by another object
in space.
● Solar
● Lunar
http://www.youtube.com/watch?v=tIE1MTGz4eI
Lunar Eclipse
● Happens when the Moon passes through Earth’s
shadow so that some or all of the Moon can only be
seen by reflected light from Earth. Lunar eclipses
happen more often than solar.
Draw this diagram of a lunar eclipse!
They typically happen About 2-3 per year
Solar Eclipse
● A solar eclipse is when the Moon passes between the
Sun and the Earth, so that light from the Sun is
partially or totally blocked.
http://www.youtube.com/
watch?v=_201ttTSG30
Draw this diagram of the Solar
Eclipse!
Total Eclipse
● COMPLETE BLOCKING OF LIGHT!
● Total eclipses rare – only once every 360
years!
Partial Eclipse
● Blocking of only a PORTION OF
LIGHT.
http://highered.mcgraw-hill.com/sites/0072482621/student_v
iew0/interactives.html
Click on interactives then scroll down and click eclipse
interactives
Total Lunar Eclipse
● Blood Moon-moon appears coppery red due to dispersed light from
Earth’s sunrises and sunsets.
In Your Notebook:
● Please answer the following questions in
complete sentences and be prepared to discuss:
1.
2.
3.
4.
5.
6.
What impact does the Moon have on Earth’s
oceans?
What impact does the Sun have on Earth’s
oceans?
What causes a high tide?
What causes a low tide?
What is a solar eclipse? Draw and label a solar
eclipse in your notebook.
What is a lunar eclipse? Draw and label a lunar
eclipse in your notebook.