AIM: How do interactions among objects in
space and their forces affect objects and cause
predictable & regular changes on Earth?
5/1/13
DO NOW:
1. Pick up today’s quiz &
finish it
2. Put last night homework in
the basket.
HOMEWORK:
1. Read p. 1-6 in your PS ILS
Review Book.
2. Answer Questions #1-33
from p. 7-13 on the
scantron.
SCANTRON DUEtomorrow by 8 AM
3. Study for tomorrow’s quiz
on PKKI#1
4. LE ILS Flash Cards DUE-5/6
Identify the objects that make up our solar system.
 Sun
 Planets & their moons
 Asteroids
 Comets
 Meteoroids
What force holds all of these objects in orbit around the sun?
 Gravity
What two factors determine
the gravitational attraction?
 A body’s mass
 Its distance from the object
How does mass affect an
object’s gravity?
 The greater the mass of an
object, the greater its
gravity
How does distance from an
object affect gravity?
 The closer an object is to
another in space, the more
gravity it will experience
ILS Question
Which force keeps the
planets in their orbits
around the Sun?
(1) gravity
(2) magnetism
(3) electricity
(4) friction
Which body in our solar
system is classified as a
star?
(1) Earth
(2) Mars
(3) Venus
(4) Sun
ILS Question
The diagram at right shows a
portion of the solar system
as seen from space.
For which object is the
lighted surface shown
incorrectly?
ILS Question
In the diagram below, the letters A,
B, and C represent three identical
satellites and their relative
distances from Earth as seen from
space.
1. Which satellite would
experience the strongest pull of
Earth’s gravity?
2. State a scientific principle that
explains your answer in
question 1.
3. Predict what might happen to
satellite B if the forces acting on
it become unbalanced.
What is rotation?
 The spinning of the Earth on its axis
What is revolution?
 The movement (orbit) of the Earth around the sun
What causes day/night
here on Earth?
 The rotation of Earth on
its axis
How long does it take for
the Earth to make one
rotation on its axis?
 24 hours (1 day)
How long does it take the
Earth to make one
complete orbit
(revolution) around the
sun?
 365.25 days (1 year)
What causes seasons on
Earth?
 Tilt of the Earth’s axis
 The revolution (orbit) of
the Earth around the Sun.
At which position is the
earth experiencing summer
in the Northern
Hemisphere?
A
ILS Question
Earth at one point in its orbit
around the Sun. The length of
daylight experienced at different
latitudes on a given date is shown
on the diagram.
1. Describe how the length of
daylight changes from the
Equator to the North Pole on
the date shown.
2. What season is beginning in the
Northern Hemisphere?
3. Explain why the South Pole
receives 24 hours of daylight on
the date shown.
ILS Question
The diagram below shows
Earth, as viewed from space,
as it moves around the Sun.
The Sun appears to move
across the sky during the
day. The best explanation
for this apparent motion
is that Earth is ________.
Approximately how long
does it take Earth to move
from position A to position
B?
ILS Question
The diagram below shows Earth as seen from space.
Letters A through D are locations on Earth’s surface.
When Earth is in this position, which location would
experience the greatest number of daylight hours?
ILS Question
The diagram shows Earth’s
revolution around the Sun as
viewed from space. Positions A,
B, C, and D represent the
beginning of each season on
Earth.
1. State one reason that Earth
has seasons.
2. If Earth were at position D,
how much time would it
take to return to position D?
3. Which season begins in the
Northern Hemisphere when
Earth is at position A?
How are we able to see the
moon in the night sky?
 The moon reflects the sun’s
light
What causes the moon to
change phases during the
month?
 The revolution of the moon
around the Earth.
How long does it take the
moon to go from full moon
phase to the next full moon
phase?
 29 days
Which position indicates a full moon phase?
C
Which position indicates a new moon phase?
A
ILS Question
The diagram shows the position of
Earth and four positions of the Moon
during one orbit of Earth.
1. On the diagram, draw an X to
show where the Sun would need
to be located to create the Moon
phases shown.
2. Which letter in the diagram shows
the position of the Moon when an
observer on Earth sees a full
Moon?
3. What motion is represented by
the arrows in the diagram?
ILS Question
Approximately how long
does it take to cycle from
one new Moon to the next
new Moon?
(1) a day
(2) a week
(3) a month
(4) a year
How does a lunar eclipse occur?
 Moon passes into the Earth’s shadow
 Earth is between the sun and the moon
 Only during the Full moon phase
How does a solar eclipse occur?
 Earth passes into the moon’s shadow
 Moon is between the Earth & Sun
 Only during the New Moon phase
What are tides?
 The rising and falling of
our ocean waters along
our coast
What causes tides?
 The Sun’s & moon’s
gravity