1. Our Solar System
Unit 5: Sixth Grade

2. Our Solar System
Did you know that planets, when viewed from Earth, look like stars to the naked eye?
Ancient astronomers were intrigued by these “stars” which seemed to wander in the sky

3. Our Solar System
Ancient astronomers named these “stars” planets, which means “wanderers” in Greek.
These astronomers knew planets were physical bodies and could predict their patterns.
But it was not until Galileo used a telescope in the 1600’s that we able to explore these other worlds.

4. A Combination of Systems
Our solar system includes the Sun, the planets and many other smaller objects.
Some planets, such as Saturn, have several moons that orbit them, and in this way, our solar system is a combination of many other systems

5. The Discovery of the Solar System
Up until the 1600’s, the universe was thought to have only 8 bodies (things): the Earth, the Sun, the Earth’s Moon, and Mercury, Venus, Mars, Jupiter and Saturn.
They are the only bodies visible without a telescope

6. The Discovery of the Solar System
After the discovery of the telescope, more discoveries were made and the current model of our solar system was in place by the 1900’s

7. Inner and Outer Solar System
Our solar system is divided into two main parts:
The inner solar system
The outer solar system
The inner solar system contains the four planets that are closest to the sun
The outer planets contains the planets farthest from the sun

8. Inner and Outer Planets
Inner Planets
Outer Planets
Mercury, Venus, Earth, Mars.
More closely spaced together
Known as terrestrial planets as they are dense and rocky
Jupiter, Saturn, Uranus, Neptune, Pluto*
Larger in size and tend to be made of gases
Known as “Gas Giants”

9. The Inner Planets
Inner planets are also called terrestrial planets because they are very dense and rocky.
They are the four planets closest to the sun: Mercury, Venus, Earth, Mars

10. Mercury Distance from the sun: 36 million miles
Period of revolution: 88 days (year)
Period of rotation: (59 days)
Average temperature:332F,
Diameter: 3,032 miles,
Closest planet to the sun.
Because there is less gravity, you would only weigh 38% of what you do here on Earth!

11. Venus 67.2 million milesfrom the sun Period of revolution: 224 days
Period of rotation: 243 days
Average temperature:457F,
Diameter: 7,520 miles,
Sun rises in the west and sets in the east.
Sometimes called “Earth’s Twin” as it is similar in size and distance from the sun.

12. Earth Distance from the sun: 93 million miles
Period of revolution: days
Period of rotation: 24 hours
Average temperature: 57F,
Diameter:7,926 miles,
The only planet to support life in our solar system.

13. Mars Distance from the sun: 141 .6 million miles
Period of revolution: 687 days
Period of rotation: 24 hours, 40 minutes
Average temperature: - 81 °F,
Diameter: 4,222 miles
The most studied planet after Earth.
While there is no water on Mars presently, there is evidence that it was once present

14. What makes our Earth different from other planets?
We have life on Earth due to several reasons:
The “perfect” star
The right distance from the star
Revolution around the star
23.5 degree tilt
Rotation on our axis
WATER

15. The Outer Planets
Because they are so much larger than the inner planets, the outer planets are called gas giants.
Gas giants are planets that have deep, massive atmospheres rather than hard, rocky surfaces like the inner planets have.
The Outer Planets include: Jupiter, Saturn, Uranus, Neptune, and Pluto*

16. Jupiter Distance from the sun: 483.6 million miles
Period of revolution: 11 years, 313 days
Period of rotation: 9 hours, 54 minutes
Average temperature:- 202F
Diameter: 88,846 miles
The largest planet in our solar system
The red spot is a 400 year old storm that is 3 times the diameter of Earth!

17. Saturn Distance from the sun: 886.7 million miles
Period of revolution: 29 years, 155 days
Period of rotation: 10 hours, 42 minutes.
Average temperature:-202 °F
Diameter: 74,900 miles
The second largest planet.
The rings around Saturn are made of icy particles.

18. Uranus Distance from the Sun: 1,784 million miles
Period of revolution: 83 years, 273 days
Period of rotation: 17 hours, 12 minutes
Average temperature:-328 °F,
Diameter: 31,763 miles
Uranus is tipped on its side and one of its poles is always dark, depending on where the planet is on its journey around the sun.
This tilting is thought to be a result of being hit by a massive object.

19. Neptune Distance from the Sun: 2,794 million miles
Period of revolution: 163 years, 263 days
Period of rotation: 16 hours, 6 minutes
Average temperature:-353 °F
Diameter: 30,779 miles
Neptune has a Great Dark Spot similar to Jupiter’s Great Red Spot.
Neptune has a narrow set of rings.

20. Pluto* Distance from the Sun: 3.67 billion miles
Period of revolution: 248 years, 4 days
Period of rotation: 6 days, 10 hours
Average temperature:-378 °F
Diameter: 1430 miles
Pluto was reclassified as a dwarf planet in 2006.
Less than half the size of Mercury and mainly made of ice and rock.
It’s moon, Charon, is almost the same size as Pluto.

21. Fun Space Facts
Pluto never made a full orbit around the sun from the time it was discovered to when it was declassified as a planet.
There are more stars in space than there are grains of sand on every beach on Earth.
It rains diamonds on Saturn and Jupiter.
If you dug a hole to the center of the Earth and dropped a book down, it would take 42 minutes to reach the bottom.

22. Solar System Distances
EQ: How does the Earth differ from the other planets in our solar system?

23. Our Solar System
Our solar system is heliocentric, meaning that the sun is at the center of our solar system, and the planets, their moons, and other space objects revolve around it.

24. What keeps us, and the other planets in orbit around the sun?
Two words: gravity and inertia!
Gravity is the force that keeps the planets in the Sun’s orbit.
Inertia is the law that an object in motion will stay in motion unless acted upon by an outside force.

25. Gravity
In the case of the sun and the planets, the Sun is larger and has more mass, and thus a stronger gravitational pull.
It’s always tugging us toward it, wanting to suck us in and burn us alive!!!
So it’s a wonderful thing that we also have inertia…

26. Inertia
Inertia works against that gravity to keep us from being sucked into the sun.
Because of inertia, planets want to travel in a straight line and never stop moving in that straight line.
So it’s a good thing that we have gravity …

27. Gravity and Inertia
Because gravity keeps us from flying off into space (never to be seen again)!
Gravity and inertia’s fight for the planets is what keeps us in the Sun’s orbit.

28. Space
The most remarkable thing about space may be that so much of it is absolutely empty.
Think of space as a building the size of huge city that holds only a handful of dust.
The dust represents the objects in space (such as the planets of our solar system)

29. Today’s Activity
Today we will be going outside to do a scale measurement model of the distances between the planets as well as each planet’s distance from the Sun.
You are to exhibit behaviors so that as far as anyone in the community is concerned, we are a nice, normal school.
Each planet group will be in charge of their scale model of their planet.
You are to complete any incomplete work on your activity sheet for HW this evening.