Transcript Dynamics of the Sun-Earth

Dynamics of the Sun-Earth-Moon System
• Lunar Phases (Apparent Shape)
• Eclipses and Tides
The Earth and
the Moon
The Moon’s shape
appears to change
Last Quarter
Waning Crescent
Waning Gibbous
Full Moon
New Moon
Waxing Crescent
Waxing Gibbous
First Quarter
The entire cycle takes 29.5 days
A NonRotating
Moon
A
Rotating
Moon
Solar and Lunar Eclipses
• The earth and moon don’t cast there own light,
instead they reflect the suns light and cast cone
shaped shadows into space.
• Eclipse- Passing of one planetary body through
the shadow of another.
• SO WHY DON’T THEY HAPPEN EVERY
MONTH???
Solar and Lunar Eclipses
Lunar Eclipses - Can occur during a
full moon
Umbra
Penumbra
Sun
Earth
Uneclipsed Moon
Sunlight
Penumbral Eclipse
Total Lunar Eclipse
Partial Lunar Eclipse
Total Lunar Eclipse
(Note the ruddy scattered sunlight)
Partial Lunar Eclipse
Earth Shadow during Lunar
Eclipse
Multiple Exposure
Photograph
Facts on lunar eclipses
• Lunar eclipses can last for 3 hours because the
earth and the moon move slow relative to each
other.
• A lunar eclipse is visible over an entire
hemisphere and is seen at the same time by
everyone looking at the full moon.
• each eclipse may have its own visual
characteristics.
Solar Eclipse - Occur if the Moons
Shadow reaches the earth.
The temperature can drop by 10 degrees, birds stop singing and flower
begin to close.
An eclipse can last up to 7 minutes 31 seconds because of the earth’s
rotation.
At least 2 eclipses occur each year although most are partial
Umbra
Sunlight
Moon
Penumbra
Earth
Total Solar Eclipse
A Partial Solar Eclipse
From Mir 1999
Future Locations for Solar Eclipses
Mr. Taylor’s Favorite Eclipses
What causes tides?
Who discovered the tides?
• Sir Isaac Newton identified the rise and fall
of the water along coast lines.
• According to Newton's law of gravitation
the moons pull on the earth and its waters
causing the tides.
The Moon pulls on the Earth, but not
the same everywhere.
The effect is the following “reality”
As earth
rotates - any
location will
experience 2
high and 2
low tides.
Spring Tides - “strong” because both the
moon and the sun pull in the same direction.
Neap Tides
“weaker”
tide because
the moon
and Sun
pulling at
90 degrees