7.1 EARTH MOTION AND
SEASONS
A. Earth’s Physical Data
1. spherical shape (almost)
2. bulges at equator
3. gravity = 9.8 m/s
4. Table 1 (page 180)
B. Earth in Motion
1. axis- imaginary line drawn from the north to
south pole
2. rotation- Earth spinning around on its axis
-causes day and night
3. revolution- Earth traveling around the sun
-elliptical pattern is an orbit
-causes seasons
-not a whole # of days (365 ¼)
4. tilt- 23.5 degree angle
-hemispheres have opposite seasons
-regions near equator have equal hours of
day and night all year
5. Solstice- sun reaches it’s greatest distance
north or south of the equator directly over the
Tropic of Cancer or Tropic Capricorn
a) Summer Solstice
-sun is highest in the sky at noon
-longest day of the year for us
-June 21st in the N. hemisphere
-Dec. 21st in the S. hemisphere
b) Winter Solstice
-sun is lowest in the sky at noon
-shortest day of the year for us
-Dec. 21st in the N. hemisphere
-June 21st in the S. hemisphere
6. Equinox- sun is directly over equator
-length of day and night are equal all
over the world
a) Spring Equinox
-March 21st in the N. Hemisphere
b) Fall Equinox
-Sept. 21st in the N. Hemisphere
7.2 EARTH’S MOON
A. Moon’s Surface Features
1. Maria- dark colored areas that
look like oceans formed by lava flows
2. Lunar Highlands- higher than the
maria
3. Craters- depressions formed from
meteorites striking the surface
B. Layers of the Moon
1. Crust
2. Rigid Mantle
3. Non-rigid Mantle
4. Small, dense
core
C. Motions of the Moon
-the moon always keeps the
same side facing the Earth
-27.3 days to orbit the Earth
-27.3 days to rotate once on its
axis
D. MOON PHASES
(refer to worksheet)
1.
2.
3.
4.
New Moon
Waxing…grows in size
Full Moon
Waning…decreases in size
E. ECLIPSES
1. Definition- shadows cast by Earth or the moon onto
each other
-only occur when the sun, moon, and Earth
are perfectly lined up
2. Solar Eclipse
-moon blocks sun from reaching a portion of the
Earth’s surface
-occurs during a new moon
3. Lunar Eclipse
-Earth blocks sun from reaching the moon
-moon appears deep red
F. ORIGIN OF THE MOON
1. Co-formation- Earth and Moon formed at the
same time from the same material
2. Capture- Earth and moon formed at different
locations, then Earth’s gravity captured the
moon
3. Fission- moon formed from a large mass of
material thrown off of a rapidly spinning Earth
4. Collision- a huge space object collided with
Earth, throwing large amounts of gas and
debris into orbit around Earth….condensed to
form moon
7.3 OUR SOLAR SYSTEM
A. SOLAR SYSTEM
•
•
•
•
•
•
Sun
Planets
Asteroids
Comets
Moon
stars
May have formed
from a cloud of
rotating ice gases
and dust called
a “nebula”
B. ASTRONOMICAL UNIT (AU)
1. Distance between Earth
and Sun
2. Used to measure
distances between objects
within the solar system
C. SUN
1.The sun is a star.
2.It produces energy by fusing
hydrogen into helium in it’s
core.
3.It contains more than 99% of
all matter in our solar system.
D. OTHER OBJECTS
1. Asteroids- small, rocky objects that lie in a belt
between Mars and Jupiter
2. Comets- made of rock particles and ice
-as they approach the sun, parts of
comets vaporize and form tails that point
away from the sun
3. Meteoroids- pieces of comets or asteroids that
travel through the solar system
a. Meteoroid- rock in space
b. Meteor- rocks entering Earth’s
atmosphere
c. Meteorites- rocks fall and land on Earth
COMET IMAGES
E. PLANETS
Mercury - solid
Venus - solid
Earth - solid
Mars - solid
Jupiter - gaseous
Saturn - gaseous
Uranus - gaseous
Neptune - gaseous
My Very
Excited
Mother Just
Served Us
Nachos!