Download Passport Earth, Moon and Sun

Passport Science
Space Unit –
Part 2 of 3
PowerPoints
(Textbook reference Chapters 12, 13, 14, 15 and 16)
1
The Sun (Textbook reference 14-2
• The sun is an ordinary star.
• The sun is the biggest,
brightest, and hottest object in
the solar system.
• Its energy is the result of the
fusion of hydrogen nuclei into
helium nuclei.
• The sun is made of about 70%
hydrogen and 28% helium.
Our Sun is a star that has already spent
about 5 billion years on the main sequence.
Scientist believe our Sun is roughly halfway
through it's life.
Source: The British Astronomical Association
Characteristics of the Sun
• Interior: Core, Radiation Zone, Convection
Zone
• Exterior: Photosphere, Chromosphere, Corona
• Features: Sunspots, Prominences, Solar
Flares
• Central star in our solar system around which
planets revolve
• Composed of gases (H2 and He) burning at
15,000,000 o C
4
The Sun: Seasons
(Textbook Reference 12-1)
Seasons:
Solstices
sun directly overhead
two times a year (June 21 and December 21)
June=longest day, December=shortest day
Equinoxes
halfway between solstices
neither hemisphere is tilted toward the sun
daylight and darkness=equal
5
What causes the seasons?
1. 23.5° tilt of Earth’s axis
2. Direct vs. indirect sun
rays
3. Length of daylight
6
In one year the earth revolves
around the sun one time.
Fall
Summer
For every time
Earth rotates on
it’s axis, one
day passes.
Sun
Winter
In one year the
earth rotates on
its axis one 365
times.
Spring
Which season is it when the south end of
Earth’s axis is tilted toward the sun?
7
Stars are the source of light for
all objects in outer space
Earth’s Moon
Phases of the Moon
(Textbook reference 12-3)
waxing = increasing waning = decreasing
gibbous = > ½
crescent = < ½
9
Lunar Phases
• New Moon
• Waxing Crescent
• First Quarter
• Waxing Gibbous
• Full Moon
New
Waxing
FirstFull
Quarter
Gibbous
Waxing
Crescent
10
Lunar Phases
• Full Moon
• Waning Gibbous
• Last Quarter
• Waning Crescent
• New Moon
Waning
Last Full
Quarter
Gibbous
Crescent
New
11
Rotate vs. Revolve
• Rotation – spin of an object on its axis
• Revolution – orbit of an object around
another object
12
Moon’s Orbit and Phases
13
Why does one side of the
moon always face us?
• Moon rotates once every 27.3 days
• Moon revolves once every 29.5 days
• Moon’s rotation approximately equal
to its revolution
14
Eclipses
1. Lunar Eclipse
2. Solar Eclipse
3. Total Eclipse
15
16
17
A total eclipse of the sun
occurs during the day!
Only the corona is visible.
18
Tides
•Effect of gravity between
the moon and the sun
19
Spring Tides
• When the sun,
the moon, and
the Earth are all
o
aligned in a 180
angle
20
Neap Tide
• When the sun,
the moon, and
the Earth form
a 90° angle
21