Transcript Moon - My Teacher Pages

The Moon
Notes 12-3
What is the Moon?
• A natural satellite
• The only moon of the planet
Earth
Location, location, location!
• About 384,000 km
(240,000 miles)
from Earth
• 3,476 km (2,155
miles) in diameter
(about ¼ the size of
Earth)
The Moon’s Size
• The moon is 3,476 km in diameter, a little
less than the distance across the United
States.
Birth of the Moon
• First Stage
• Moon originally was once
part of the Earth.
• Scientists believe a very
large body hit the Earth
early in its development,
throwing a huge amount
of debris into orbit.
• Debris eventually was
influence by Earth’s
gravity and formed the
moon we have today.
Second Stage
• After forming a
sphere, the surface of
the moon was covered
by molten rock.
• Eventually, this mix
of rock separated.
Third Stage
•The outer surface of the
moon cooled, forming a
crust.
•Craters started to form
from the constant
bombardment by
meteoroids.
• Meteoroids decreased
• Moon cooled completely
• Moon changed little in 3
billion years
The Moon’s Surface
• No atmosphere
• No liquid water
• Extreme
temperatures
– Daytime = 130C
(265°F)
– Nighttime = -190C
(-310 F)
• 1/6 Earth’s gravity
The Moon’s Surface
• Features on the moon’s surface include
maria, craters, and highlands.
Highlands
• Mountains up to
7500 m (25,000 ft)
tall
• Light colored
features
Craters
•
•
•
•
Bowl shaped depressions
Up to 2500 km (1,553 miles) across
Most formed by meteorite impact on the Moon
Some formed by volcanic action inside the Moon
Maria
• Originally thought
to be “seas” by
early astronomers
• Darkest parts of
moon
• Hardened rock
formed from huge
lava flows 3-4
billion years ago
Craters
Maria
Movements of the Moon
• Orbit is an ellipse,
not circular
• Revolution – Moon
orbits the Earth every
27 1/3 days
• Same side of Moon
always faces Earth
Far Side of the Moon
• First seen by Luna 3
Russian space probe in
1959
• Surface features
different from near
side
– More craters
– Very few maria
– Thicker crust
It’s Just a Phase
• Moonlight is reflected
sunlight
• Half the moon’s surface is
always reflecting light
• From Earth we see
different amounts of the
Moon’s lit surface
• The amount seen is called
a “phase”
Waxing and Waning
•
•
•
•
•
•
•
•
•
New moon
Waxing Crescent moon
First Quarter moon
Waxing Gibbous moon
Full moon
Waning Gibbous moon
Third Quarter moon
Waning Crescent moon
New moon
last (third)quarter
waning Moon
moon orbit`s
earth
SUN
gibbous moon
crescent
earth
full moon
new moon
gibbous moon
crescent
waxing Moon
first quarter
FOUR MAIN SHAPES
FULL
QUARTER
CRESCENT
GIBBOUS
Lunar Eclipses
• Moon moves into Earth’s
shadow – this shadow
darkens the Moon
• About 2-3 per year
• Last up to 4 hours
• Only during full moon
Lunar Eclipse
• During a lunar eclipse, Earth blocks
sunlight from
reaching the moon’s surface.
Solar Eclipses
• New Moon moves
between Earth and
Sun
• Moon casts a shadow
on part of the Earth
• Total eclipses rare –
only once every 360
years from one
location!
Solar Eclipse
• A solar eclipse occurs when the moon passes
directly between Earth and the sun, blocking
sunlight from Earth.
Annular Solar Eclipse
May 20, 2012
• http://youtu.be/w806rVCEh50
• 1950s to 1960s probes
• Neil Armstrong
First man on the Moon
– July 20, 1969
• Six Apollo missions
(1969-1972)
• 12 Americans have
walked on the moon
• Possibly send people to
moon again in 2018
Exploring the
Moon
Extra Credit for Astronomy Test:
• Go to the website nasa.gov
• Find a topic that you are interested in and print
out the information. Write a ½ page summary
of the information that you find, and ½ page of
why you find this topic interesting and what
other questions do you have regarding the topic.
• 5 points
• Due Wednesday