Properties
☼ Earth is a sphere
☼ Aristotle believed the
Earth was round
because of the
shadow cast on the
Moon during a lunar
eclipse. (circa 350
B.C.)
☼
Earth bulges slightly
at the equator & is
somewhat flattened at
the poles.
Rotation
☼
The amount of time
it takes an object to
make one full spin on
its axis.
☼
Rotation causes
day & night.
☼
Earth’s rotation is
23 hrs, 56 min
Revolution
☼
The amount of time it takes for one object to make
one full trip around another larger object in space.
☼
The orbit path is elliptical.
☼
Earth’s revolutionary period is 365.25 days
Magnetic Field
☼
The movement of
Earth’s core material
& Earth’s rotation
generates a
magnetic field.
☼
Protects Earth
from some of the
solar radiation.
☼
The magnetic axis
is inclined at 11.5o
from the rotational
axis.
The distance between the Earth and its
moon averages about 238,900 miles
(384,000 kilometers). The diameter of
the moon is 2,160 miles (3,476
kilometers).
The Seasons
☼
Earth’s Orbit & Tilted Axis
 Whether the Earth is closer to the
Sun or further away has NOTHING
to do with its seasons.
Earth’s axis is tilted 23.5o
The tilting of the axis results in
part of the Earth receiving more
direct sunlight at times causing
the seasons.
Solstices
 The day when the
Sun reaches its
greatest distance
north or south of the
equator.
 The summer solstice
is the 1st day of
summer and has the
longest number of
daylight hours
during the year.
 The winter solstice
is the 1st day of
winter and has the
shortest number of
daylight hours
during the year.
Equinoxes
 The two days out
of the year when
the Sun is directly
over the equator.
 1st day of autumn
& spring.
 The number of
daylight hours are
nearly equal all
over the world.
 Neither
hemisphere is
tilted toward the
Sun.
How did the moon form?
According to the "giant
impact" theory, the
young Earth had no
moon. At some point in
Earth's early history, a rogue
planet, larger than Mars,
struck the Earth in a great,
glancing blow. Instantly, most
of the rogue body and a
sizable chunk of Earth were
vaporized. The cloud rose to
above 13,700 miles (22,000
kilometers) altitude, where it
condensed into innumerable
solid particles that orbited the
Earth as they aggregated into
ever larger moonlets, which
eventually combined to form
the moon.
The Moon is 4.5
billion years old.
+ The distance From Earth is 363,301
kilometers (225,745 miles).
Motions of the Moon
☼ Rotation period = 27.3 days
☼ Revolutionary period = 27.3 days
☼ Since both motions are the same, the
same side of the Moon ALWAYS faces
the Sun.
☼This produces the phases of the Moon.
If the moon were placed on the surface of the
continental United States, it would extend from
San Francisco to Cleveland (2,600 miles)
☼
Phases of the Moon
☼ Each phase is determined by the positions
of the Earth, Moon, & Sun.
☼ Waxing occurs when the lighted side of the
Moon begins to show more & more.
☼Waning occurs when the lighted side
becomes less and less.
 The thin sliver of the lighted side is
called a Waxing Crescent.
 When the right half of the lighted
side is showing, its called a 1st
Quarter Moon.
 When more than half of the lighted
side is showing, its called a Waxing
Gibbous.
 A Full Moon occurs when all of the
lighted side of the Moon is showing.
☼ A New Moon occurs when the Moon
is between the Sun & Earth. The dark
side of the Moon faces the Earth
while the lighted side faces the Sun.
The moon is not up during the night.
☼ A Waning Gibbous occurs after the
Full Moon.
☼ When the left half of the Moon is
showing, a 3rd Quarter Moon occurs.
☼ A Waning Crescent occurs next
followed by the New Moon again.
Eclipses
☼ Solar Eclipses
 The Moon, during the New phase, blocks the
Sun by passing in front of it.
 The shadow cast on the Earth by Moon during
the eclipse is called the umbra. A total eclipse
is seen here.
 A partial eclipse is seen in the penumbra,
which is a lighter shadow.
SOLAR ECLIPSE
Penumbra
Umbra
☼
Lunar Eclipse
 The Earth passes between the Sun & Moon.
The Earth casts its shadow on the surface of
a Full Moon.
 Light passing through the Earth’s
atmosphere during a total lunar eclipse can
sometimes make the Moon turn red.
 More common than solar eclipses.
+ Do you know the moon’s
name? It’s Luna.
The word "lunatic" comes from when
doctors thought that the insane were
"moonstruck."
Lunar ECLIPSE
Penumbra
Umbra
The Moon’s Surface
& Interior
☼ Lunar Surface
 No atmosphere
 Covered in craters
caused by meteor
impacts.
 Dark, flat regions
made of basaltic
lava flows are
called maria
(mare.)
Lunar Interior
☼Crust of the light side of the Moon might
be thinner than the dark side of the Moon.
☼The upper mantle of the Moon is solid with
a partially melted lower mantle.
☼The core may be solid & iron-rich.
The moon is actually
moving away from earth
at a rate of 1.5 inches
per year.
The temperature on the Moon reaches 243° F at midday
on the lunar equator. During the night, the temperature
falls to -261° F.
“We choose to go to the
Moon.”-JFK
☼ Project Mercury
Shepard's
 Goal: orbit a piloted
Freedom
7 flight
spacecraft around the
lasted 15
m 28s.
Earth and bring it back
John
safely.
Glenn’s
ride into  Alan B. Sheppard was
space
was a
the 1st US citizen in
total of 4
hours, 55 space (1961)
minutes,
 John Glenn was the 1st
and 23
seconds.
US citizen to orbit the
Earth.
Project Gemini
 Goal: Teams of two astronauts in the same
spacecraft meet up & connect with another
spacecraft.
The Gemini Program was a step between Project Mercury and the
Apollo Program, and had four objectives: 1) To subject astronauts to
long duration flights 2) to develop methods of docking with and
maneuvering other orbiting vehicles in space; 3) to perfect methods of
reentry and landing the spacecraft 4) to gain additional information
concerning the effects of weightlessness on crew members and to
record the reactions of crew members during long duration flights.
Project Apollo
 Goal: Successfully land a person on the Moon.
 Apollo I: Destroyed on the launch pad when an
electrical fire erupted in the cockpit, killing the 3
person crew.(1967)
The hatches could not be opened,
because of the pressure of the hot
gasses inside the command
module, which soon ruptured.
Emergency evacuation was very
complicated, and had never been
done in a little as 90 seconds.
Rescue efforts were
unsuccessful. 27 men were
treated for smoke inhalation, two
were hospitalized.
Edward White, Gus Grissom, Roger Chaffee
 Apollo XI: Neil Armstrong & Edwin “Buzz” Aldrin
successfully land on & explore the Moon. (1969)
Just twenty seconds' worth of fuel remained
when Apollo 11's lunar module landed on the
moon.
The footprints left by the
Apollo astronauts will not
erode since there is no
wind or water on the
Moon. The footprints
should last at least 10
million years.
Astronauts Neil Armstrong, left,
Michael Collins, center, and
Buzz Aldrin
+ It would take 135 days to drive
by car (~70 mph) to the moon
The average desktop computer contains
5-10 times more computing power than
was used to land a man on the moon.
 Apollo XIII: An explosion occurred in one of the
oxygen tanks two days into the mission.
 The crew was unable to land on the Moon, but
returned safely to Earth 4 days later.
Left to right: Lovell, Swigert, Haise
Square peg in a round hole
Mission control during splash down
 Apollo XVII: The last mission to the Moon.
The 1st geologist (scientist) explores the
Moon.
Gene Cernan was the last
man to step on the moon
in 1972.

Total Solar Eclipse August 21, 2017