1. What are Stars and Planets?
UNIT D THE SOLAR SYSTEM
What are Stars and Planets?

2. An astronomer is a
person who studies
the universe.

3. THE NIGHT SKY Did you ever notice the sky on a clear night?
There are many stars, too many of them to count.
They look like small dots of light in the sky.
They only look small because they are so far away.
Stars are really much bigger than Earth.

5. STARS
A star is a big ball of hot gases.
The hot gases give off light. This light is what
we see from Earth. They also give off heat.
The sun is the closest star to Earth.
Did you ever wonder why some stars are bigger and brighter than other stars?

6. The brightness of a star depends on their size,
their heat, and their closeness to Earth.
All stars are not the same sizes and temperatures.
The bigger and hotter a star is, the brighter it will be.
A stars closeness to Earth will also make it brighter.
The closer a star is to Earth, the brighter it will be.

7. THE SUN

8. FACTS ABOUT THE SUN The sun is a star. It is the closest star to
Earth.
The sun is much larger than the Earth. It only looks smaller because it is so far away.
Like other stars, the sun is made of hot gases.
Because these gases are so hot, they give off light and heat.

9. Some people use a telescope to look at the night sky.
A telescope makes stars look closer and larger.

10. CONSTELLATIONS A group of stars that form a star
picture is called a constellation.
Long ago, people saw pictures in these groups of stars.
They began naming the different star pictures.
There are about 88 constellations in the entire sky.

11. Let’s look at some of our constellations……

12. Big Bear and Big Dipper
The Big Bear (Ursa Major) constellation contains a group of seven stars
called the Big Dipper.
Together these stars form the shape of a dipper, a kind of spoon.

13. Polaris, or the North Star, can be found
at the end of the handle of the Little Dipper.
People long ago used it like a compass
because it was so easy to spot, and
always leads you to the north.

14. Orion the Hunter…..
Can you see the shoulders, belt with sword hanging, the bow, and his hand
pulling back the bow????

15. THE SOLAR SYSTEM The sun is the closest star to Earth.
Eight planets, including Earth, move around the sun.
A planet is a large ball of rock or gas that travels around the sun.
Together, the sun, the planets, moons, comets, asteroids, and
meteoroids make up our solar system.
The sun is the only star in our solar system.

16. OUR GALAXY Our galaxy is the Milky Way Galaxy.
The Milky Way galaxy includes the entire
solar system and hundreds of billions of stars.

17. Mercury the planet closest to the sun.
Small rocky and hot planet
Dusty surface with craters
Looks like Earth’s moon
36 million miles from sun

18. Venus is second planet from the sun.
Can be seen shining in the
night sky
Dry ,hot planet with tall
mountains and deep valley
Thick yellow clouds, blown
around by strong winds
About the size of Earth
67 million miles from sun

19. Earth, our planet, is the third planet from the sun.
Almost cover by water
Ball of rock
Not too hot or too cold
Only planet with plants and
animals
93 million miles from sun

20. Mars is the fourth planet from the sun.
Desert, except for ice caps
at each end
Tall mountains and deep
canyons
Red planet(soil full of rust)
Strong winds blow up red
dust
141 million miles from sun

21. Jupiter is the fifth planet from the sun.
Biggest planet
Ball of gas, rocky center
Yellow, tan, red, orange,
and white clouds blown by
strong winds
Giant red spot, scientists
think it’s a storm)
483 million miles from sun

22. Saturn is the sixth planet from the sun.
Ball of colored gas
Rocky center
Pretty rings made of bits of
ice and rock
885 million miles from sun

23. Uranus is the seventh planet from the sun.
Gas planet, rocky center
Thin, dark rings
Blue-green color
Covered by thick haze
Tilted on side, moves around
the sun like a rolling ball
1billion 779 million miles
from sun

24. Neptune is the eighth planet from the sun.
Gas planet
Center of rock and iron
Greenish color
Cover with clouds
2 billion 788 million miles
from sun

25. What about Pluto? After it’s discovery in 1930, Pluto was
considered the ninth planet in the solar system.
From 1930 until 2006, we had
limited information about Pluto.
We did not gain a realistic understanding
of it’s characteristics until 2006.
In 2006, Pluto was classified as the
2nd largest known dwarf planet.
There are just 5 known dwarf planets at
this time. But, scientists know there are
many more to be discovered.

26. Meteoroids
Meteoroids are made of small
chunks of rock and ice.

27. Asteroids
Asteroids are chunks of rock
and metal.

28. Comets
Comets are frozen balls of dirty ice.