Download Phases of the Moon, Planets, and Seasons 4th Grade Science

Phases of the Moon, Planets, and Seasons
4th Grade Science
Teacher Essential Questions and Answers and Background Knowledge:
Why does the moon look different as it orbits the earth?
The moon is a satellite that orbits the earth. Its shape only “appears” to change. It is the amount of
reflected light that we see that changes during the lunar cycle. The cycle is about 29.5 days in length.
The moon does not make its own light. It is reflected from the sun. As our Moon orbits the Sun, only
the side facing the Sun is illuminated.
What we see from Earth changes during a month. Beginning with the dark
new moon we see the lighted part of the moon from just a sliver to a half, to
a full Moon. Then the lighted part of the moon begins to decrease and get
thinner until there is no visible part of the moon and the cycle begins again.
What causes the phases of the moon?
When the moon orbits between the Earth and the Sun we have a New
Moon. It looks dark because the lighted side is facing away from the Earth.
The Moon continues to move counterclockwise around the earth until we
see the Full Moon. The Full Moon stage is when the Moon has moved so the
Earth is between the Moon and the Sun.
A waxing crescent moon follows the new moon, and some light appears.
During the first quarter phase about ½ of the moon appears to be lighted on
the right hand side. More light appears as the Waxing Gibbous phase nears
the Full Moon Phases.
After a Full Moon the amount of light appears to decrease from the right
side. The term Waning Gibbous phase appears, and the moon light
decreases to ½ of a lighted moon which is the Last Quarter. Then, the moon
continues to have less light appear as it reaches the Waning Crescent stage.
The cycle has reached about 29.5 days and returns to the New Moon phases.
http://www.lpi.usra.edu/education/skytellers/moon_phases/about.shtml
Why does the Earth have Day and Night?
Day and night cycles are caused by Earth's spin on its axis. Earth turns or rotates one time every
24 hours. The part of Earth that is facing the Sun experiences day, and the part facing away from
the Sun experiences night. As Earth spins counterclockwise (viewed from above the North Pole)
the region of daylight moves across the globe from east to west.
http://home.hiwaay.net/~krcool/Astro/moon/moonphase (graphic)
Why does Earth's day length change during the year?
The Earth is tilted toward the Sun at 23.5 degrees. An average amount of daylight on any spot of
the Earth is 12 hours. However, this is different in the Northern and Southern Hemispheres.
When an area is more directly facing the sun, it has longer daylight hours. For instance in
Alaska, there are days during July which nearly all daylight hours, and during December there is
little daylight. In the Northern Hemisphere the longest day is June 21, and the shortest day is
December 21. The opposite is true in the Southern Hemisphere. During March and September
there are Equinoxes, which means there is no tilt toward the sun. Equal numbers of sunlight and
darkness occur. In the spring the North Pole moves toward 24 hours of light, and in the fall, the
South Pole moves to 24 hours of light.
http://www.weatherimagery.com/blog/myths-seasons-cause/
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Summer Solstice: June 22nd. Longest day of the year.
Winter Solstice: December 22nd. First day of winter. Shortest day of the year.
Vernal Equinox: Around March 21st. Marks the first day of spring.
Autumnal Equinox: Around September 21st. Marks the first day of fall.
What causes seasons?
http://www.weatherquestions.com/Seasons.gif
The seasons are caused by the tilt of the Earth's rotational axis away or toward the sun as it
travels through its year-long path around the sun. The Northern and Southern Hemispheres are
opposite one another.
What other factors cause seasonal changes?
During the winter, cold air masses build up over North America, Europe, and Asia, due to the low
intensity of sunlight. The oceanic air masses are much less affected by the seasons. Also important is
your location on the Earth as it plays a big role in how much of the Sun’s energy you receive on average
and how much your seasonal temperatures may vary from winter to summer.
http://www.fas.org/irp/imint/docs/rst/Sect14/high_low_beams3.jpg
The sun is higher in the sky during the summer than in the winter. More shadows are cast on the
surface during the winter months.
What is the size and order of the planets from the Sun?
The nine planets that orbit the sun are (in order from the sun): Mercury, Venus, Earth, Mars, Jupiter,
Saturn, Uranus, Neptune, and Pluto (a dwarf planet). The largest planet is Jupiter. It is followed by
Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury, and finally, Pluto (a dwarf planet). Jupiter is so
big that all the other planets could fit inside it.
http://members.enchantedlearning.com/subjects/astronomy/planets/
http://members.enchantedlearning.com/subjects/astronomy/planets/
Essential Questions and Answers for Students:
How does the moon change its shape and size?
The moon does not change its shape or size. The moon does not make its own light.
It appears differently during the month due to its position in the sky. The moon moves between earth
and the sun. As it does that the amount of reflected light that we see changes.
What is a New Moon? When the moon is between and Earth and the Sun, we have a new moon. The
moon is not visible from Earth, because the side of the moon that is facing us is not being lit by the sun.
What is a Full Moon? A full moon is the whole circle reflecting the light of the sun.
How long does it take for a moon’s cycle? The moon’s (lunar) cycle is about 29.5 days.
What happens between a New Moon and a Full Moon? The amount of light grows larger between a
New Moon and a Full Moon. The phase after the New Moon is called a Waxing Crescent. Next comes
the First Quarter phases which looks like ½ of the circle is lit. Before a Full Moon, the phase is called a
Waxing Gibbous moon. This looks almost full.
How does the moon change after a Full Moon? After a full moon the amount of lighted surface
becomes smaller. The next phase is called the Waning Gibbous. Then comes the last quarter phase.
Before the New Moon appears is the Waning Crescent stage.
What do waxing and waning mean? Waxing means the amount of light is increasing, and waning
means the amount of light is decreasing.
Where does the sun go at night? The Earth spins (rotates) on its axis. The Sun is not moving. The Sun
appears to rise in the EAST and set in the WEST. But, the Earth is actually turning toward the Sun and
away from the Sun at these times.
What causes seasons? The position of the Earth, its rotation and revolution are some factors. The
amount of heat from the Sun is another. The Earth is tilted at 23.5 degrees toward or away from the
sun.
How are seasons different on each hemisphere?
The amount of light differs because of the tilt of the Earth during its revolution around the Sun. When it
is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. When it is winter in
the Northern Hemisphere it is summer in the Southern Hemisphere. If it is spring in the Northern
Hemisphere, it is fall in the Southern Hemisphere. When it is fall in the Northern Hemisphere, it is spring
in the Southern Hemisphere.
What is the order of the planets from the sun? Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus,
Neptune and dwarf planet Pluto.
Memory sentence. “My very exceptional mother just sent us nine pizzas.”
What planet is the largest? The largest planet is Jupiter. Next are the other gas giants of Saturn,
Uranus, and Neptune.
Which planet is the smallest?
The smallest planet is the planetoid, Pluto, or Neptune.
What are the inner planets?
The four planets closets to the Sun are the inner planets. They are Mercury, Venus, Earth and Mars.
Venus and Earth are sometimes called the twin planets. Mercury is the hottest planet. The greenhouse
effect is present on Venus. Mars has been called the Red Planet. It has many craters. Earth, our planet
is the third rock from the sun, and has much water on its surface.
What are the gas giants?
The four gas giants are called that since their atmosphere has much gas. They are Jupiter, Saturn,
Uranus, and Neptune. These four planets are considerably larger than the inner planets. Jupiter has
many moons. Saturn has rings. Uranus rotates on its side and appears blue in the sky because of
methane in its atmosphere. Neptune is very cold.
Essential Vocabulary:
Rotation
Revolution
Axis
*Seasons
*Planet
*Sun
Moon Phases
Waxing
Waning
Crescent
Full Moon
New Moon
Day/Night
Orbit
Equinox
*Winter
*Summer
*Spring
*Fall
*These words should be a review of AKS previously taught.