The Stars and the Solar
System
What do you know about
the solar system?
Georgia Performance Standards
S4E1: Students will compare and contrast
the physical attributes of stars, star
patterns, and planets.
a.
Recognize the physical attributes of stars in the
night sky such as number, size, color, and
patterns.
b.
Compare the similarities and differences of
planets to the stars in appearance, position,
and number in the night sky.
c.
Explain why the pattern of stars in a
constellation stays the same, but a planet can
be seen in different locations at different times.
d.
Identify how technology is used to observe
distant objects in the sky.
Essential Questions
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What is a star?
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How are stars alike and different from each other?
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How does the sun compare to other stars in the night sky?
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How are constellations alike and different?
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Why are some constellations observed during some
seasons, but not during other seasons?
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How can technology be used to observe distant objects in
the sky?
STARS
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A star is a huge ball of hot gases.
When seen from the Earth, most
stars appear as small points of light
because they are very far away.
They form fixed patterns that change
position in the sky as Earth rotates
and revolves.
A star as seen from Earth.
Star
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A STAR is a ball of hot gases that gives off
light and other forms of energy.
Stars have different sizes. White dwarf
stars are about the size of Earth.
Supergiant stars can be wider than 300
million miles. That is more than one
thousand times the distance from Earth to
the Moon.
Dwarf star
Star
Supergiant
How many stars are there?
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On the clearest night, you can see
hundreds of stars.
The universe holds many, many
more stars than you can see from
Earth.
These stars are too far away to be
seen with the unaided eye.
The Sun
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The SUN is a star.
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It is the largest object in the solar system.
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More than 1 million Earth’s would fit inside the
sun.
The sun is a medium sized star.
It looks much larger than the stars you see at
night because it is so much closer to the Earth.
Sun
Sun
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Living things on Earth depend on the
Sun for heat and light.
The Sun also emits energy in forms
that would harm life. Fortunately,
gases in the Earth’s atmosphere
protect the surface from much of this
energy.
Constellations
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A constellation is a group of stars
that forms a pattern shaped like an
animal, person, or object.
Scientist recognize 88 constellations.
Constellations seen in the night sky
Great Bear Constellation
The Big Dipper
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Stars are always present, even
during the day.
You just cannot see them during the
day because the sky is so bright.
Each night the stars appear to move
across the sky. This is caused by the
rotation of the Earth.
Constellations
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As Earth rotates on its axis, the stars
appear to rotate in the sky.
Thus, the constellations change
position in the night sky during the
night.
Different constellations become
visible with the different seasons but
the shape of the constellations DO
NOT change.
Why do the stars in constellations
stay in fixed patterns?
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Stars are trillions of kilometers away,
far outside the solar system.
Even as the Earth moves through its
orbit around the Sun, each star
remains nearly the same distance
away.
Seasonal Constellations
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Some constellations can only be seen
on a summer night. Others can only
be seen on a winter night.
This is because the Earth revolves
around the sun. As it does, the part
of the night sky that is visible from
any one place changes.
How were constellations used long
ago?
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People depended on the constellations in
many ways.
Sailors studied them to find their way at
night.
Farmer’s used them to mark the seasons
and signal when to plant or harvest their
crops.
Northern Hemisphere
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Summer constellations
Constellations
Winter
Solar System
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The Solar System is made up of the
Sun, orbiting planets, their moons,
and other objects traveling around
the Sun.
The Sun is the nearest star to the
Earth.
Planet
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A PLANET is a large body or rock or gas in
space that moves around a star.
A planet DOES NOT produce light of its
own. That is why planets almost never
twinkle, while stars do twinkle.
You can see planets in the night sky
because of the Sun’s light reflecting, or
bouncing off, of them.
Solar System
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Earth is one of the eight planets that
orbit the sun. (Pluto is now called a
dwarf planet.)
MOON
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You can also see Earth’s moon in the
night sky.
A MOON is a small, rounded body in
orbit around a planet.
A moon does not produce its own
light. It reflects light from the sun.
Most planets have at least one moon.
Moon as seen from Earth.
Earth’s Year
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The farther a planet is from the Sun,
the longer it takes to orbit. The time
it takes to complete one trip around
the Sun is called a YEAR.
Earth’s year is about 365 days long.
Mercury makes a complete orbit in
just 88 days. Neptune takes about
165 Earth years to complete its orbit
around the Sun.
Sun, Moon, and Sky
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For thousands of years, people have
been observing the Sun, the Moon,
and other objects in the sky.
Scientists did not learn how these
objects move until a few hundred
years ago.
Why do you think they took so long?
TELESCOPES
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A TELESCOPE is a tool that makes distant
objects appear larger, brighter, and
sharper.
Telescopes help scientists study stars, the
Moon, and the planets.
Scientists have used telescopes to
discover that stars have regular patterns
and planets move among the stars.
Never Look at the Sun
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NEVER look straight at the Sun,
especially with a telescope. Doing so
can DAMAGE your eyes.
It is SAFE to look at other stars,
which are more distant.
OPTICAL TELESCOPE
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This telescope magnifies (or makes
an object appear larger) by collecting
light.
OPTICAL TELESCOPE
Hubble Space Telescope
Hubble Space Telescope
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It is different from other telescopes because it is
in space.
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It moves around the Earth every 97 minutes.
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It was launched into space in 1990.
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It is the size of a school bus.
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It takes photographs of space from beyond
Earth’s atmosphere.
RADIO TELESCOPE
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This type of telescope collects radio
waves instead of light.
Computers use the radio waves to
make pictures of space.
As more powerful telescopes are
invented, scientists learn more about
objects in space.
RADIO TELESCOPE
Essential Questions

What is a star?

How are stars alike and different from each other?

How does the Sun compare to other stars in the night sky?

How are constellations alike and different?

Why are some constellations observed during some
seasons, but not during other seasons?

How can technology be used to observe distant objects in
the sky?