Earth, Moon, and Sun

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Chapter 1 "Earth, Moon, and Sun"
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Egyptians They were one of the first groups of
people to study the stars. This helped them
determine when they should plant their crops.
They began the study of
Astronomy
The study of the moon, stars, and other objects
in space.
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An imaginary line that passes through Earths
center at the North and South poles
Axis
Earths axis is tilted at an angle of
23.5 degrees from vertical
This tilt of Earths axis is what causes the
Seasons
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Earth in Space

• Stand in place, and make one complete turn.
• You have just rotated. Take a trip around your
  desk.
• You have just revolved.
• Predict whether you could rotate and revolve at
  the same time?

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THREE "R's" OF ASTRONOMY
ROTATION - MOTION WHERE AN OBJECT TURNS ON AN
IMAGINARY AXIS. This causes
Day and Night
REVOLUTION - PLANETARY MOTION WHERE AN OBJECT
MOVES AROUND THE SUN. This causes
A year
RETROGRADE - TYPE OF MOTION IN WHICH A PLANET
APPEARS TO MOVE BACKWARDS.
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Earth in Space
Earth rotates eastward, and a point on the
equator rotates at about 1600 kilometers in an
hour!
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Earth in Space
Earths path around the sun is called an
orbit. Notice, our orbit is not a perfect circle!
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Earth in Space
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Understanding the seasons
The measurement of distance from the equator,
expressed in degrees north and south.
Latitude
One of the two days each year, when the noon sun
is overhead at 23.5 degrees north or south.
Solstice
In the Northern hemisphere, the noon sun is at
23.5 degrees south during the
Winter solstice
The date for this would be(what is the shortest
day of the year?)
Around Dec. 21st
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Equinox
Halfway between the solstices, neither hemisphere
is tilted toward or away from the sun. This only
occurs twice a year, and during this time the
noon sun is directly overhead at the equator.
Day and night would be about
equal
spring equinox occurs around March 21st, and
marks the start of spring in the Northern
Hemisphere.
Vernal equinox
Occurs around September 23, and marks the start
of fall
Autumnal equinox
How do seasonal changes affect living things?
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Earth in Space
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Earth in Space
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The Moon
The moon is about 384,400 kilometers from Earth.
The positions of the moon, Earth, and the sun
cause the phases of the moon, eclipses, and tides.
It takes the moon about 27.3 days to revolve
around the Earth in a non-circular orbit.
The moon rotates on its axis every 27.3 days.
Its day and year are equal, so we only ever see
one side of the moon.
Phases the different shapes of the moon you see
from Earth.
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The Moon
New Moon
The moon produces no light of its own. It only
reflects sunlight.
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The Moon
Waxing Crescent
New Moon
The phase of the moon you see depends on how much
of the sunlit side of the moon faces Earth.
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The Moon
First Quarter
Waxing Crescent
New Moon
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The Moon
First Quarter
Waxing Crescent
Waxing Gibbous
New Moon
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The Moon
First Quarter
Waxing Crescent
Waxing Gibbous
New Moon
Full Moon
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The Moon
First Quarter
Waxing Crescent
Waxing Gibbous
New Moon
Full Moon
Waning Gibbous
Third Quarter
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The Moon
First Quarter
Waxing Crescent
Waxing Gibbous
New Moon
Full Moon
Waning Gibbous
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The Moon
First Quarter
Waxing Crescent
Waxing Gibbous
New Moon
Full Moon
Waning Gibbous
Waning Crescent
Third Quarter
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Eclipse
Occurs when the moons shadow hits Earth, or
Earths shadow hits the moon.
Occurs when the moon passes between Earth and the
sun, blocking the sunlight from reaching Earth.
Solar eclipse
The darkest part of the moons shadow (its cone
shaped. Light from the sun is completely blocked
by the moon.
Umbra
The shadow cast by the moon that is not as dark
as the umbra. Part of the sun is visible from
Earth. People in this area, only see a partial
eclipse.
Penumbra
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Eclipses
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Unlike a solar eclipse, a lunar eclipse can be
seen anywhere on Earth that the moon is visible.
A lunar eclipse can be partial or total. It all
depends on the alignment of the Earth, moon, and
sun.
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Eclipses
Occurs at a full moon when Earth is directly
between the moon and sun.
Lunar eclipse
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Eclipses
Eclipses
What Disappears
Type
Solar Lunar
Sun Moon
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The rise and fall of water (oceans), every 12.5
hours or so. The water rises for 6 hours, then
falls for 6 hours.
Tides
Tides occur mainly because of differences in how
much the moon pulls on different parts of Earth.
The force that pulls the moon and Earth
(including our water) toward one another.
Gravity
Neap tide
Spring tide
Occurs twice a month (during 1st and last
quarter). The sun Earth moon are at a right
angle.
A tide that has the greatest difference between
high and low tide. Occurs during new moon, when
gravity of the sun and moon pull in the same
direction.
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Rockets Satellites
A rocket moves forward when gases expelled from
the rear of the rocket push it in the opposite
direction.
Remember Newtons Law For every action, there is
an equal but opposite reaction.
Early rockets (built by the Chinese in 1000) used
gunpowder as fuel.
This didnt work well, because gunpowder burns
quickly and explodes! BOOM!!!
Robert Goddard (and American) figured out rocket
fuel needed to burn slowly and continuously to
overcome Earths gravity. (1920)
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Satellite
Any natural or artificial object that revolves
around an object in space.
Who launched the 1st artificial satellite and
when???
The Soviet Union launched Sputnik 1 on Oct. 4,
1957. It stayed in orbit for 96 minutes.
When did the U.S. launch its 1st artificial
satellite, and what was its name?
January 1958--its name was Explorer 1
On April 12, 1961, Yuri Gagarin became the 1st
person in space. He was a Soviet cosmonaut.
What do we use use artificial satellites for
today?
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Geosynchronous orbit
An object that revolves around Earth at the same
rate that Earth rotates.
These are used for TV signals, and to map weather
patterns.
A large satellite in which people can live for
long periods of time.
Space station
Who launched the 1st space station when?
Soviet Union in 1971--gt it was called Salyut
The US put our 1st space station into orbit in
1973. It was called Skylab.
Currently, 16 nations are working together to
build the International Space Station
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Space shuttle
A reusable vehicle that can shuttle people
between Earth and Space.
1981
When was the 1st shuttle launched?
Next shuttle mission?
??
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Moon Facts
There is no air or water on the moons surface.
The temperature ranges from 100 to -170 degrees C.
Round pits covering the moons surface caused by
impacts are called craters.
Dark, flat areas are called Maria or seas.
The gravity on the Moon is one-sixth that of
Earth. That means a 120 lb. person would only
weigh 20 lbs on the Moon. What would you weigh on
the moon?
The moon is 3,476 km in diameter. About
one-fourth the size of Earth
People believe the moon formed by a collision
with a large object 4.5 billion years ago.
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Famous moon missions
Between 1964-1972 the US and Soviet Union sent
dozens of rockets up to the moon.
July 20, 1969- Astronauts landed on the moon.
The craft was called Apollo 11. Neil Armstrong
was the 1st person to set foot on the moon.
Much of what scientists have learned about the
moon came from the rocks that the astronauts
brought home with them.
In 1998, NASA sent Lunar Prospector up to map
the lunar surface.
In 1994 NASA sent Clementine to the moon to
photograph it.
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The Moon
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The Moon
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The Moon
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The Moon
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The Moon
Collision Theory
Material is thrown into orbit
Large objectstrikes Earth
Material breaksoff from Earth
Material in orbitforms the moon