1. Natural Sciences and Technology Grade 6
Term 4: Planet Earth and Beyond
The Solar System
(ppt 2)

2. Natural Sciences and Technology - Grade 6
Topic 1 The Solar System
The Planets
Natural Sciences and Technology - Grade 6

3. Natural Sciences and Technology - Grade 6
The Planets
Eight major planets.
Four rocky “inner” planets.
Four gaseous “outer” planets.
Includes asteroids and moons.
Orbit [pathway of the planets] around the Sun.
The Sun is the biggest and heaviest object in our Solar System.
Natural Sciences and Technology - Grade 6

4. Natural Sciences and Technology - Grade 6
Order of the planets
Natural Sciences and Technology - Grade 6

5. Natural Sciences and Technology - Grade 6
Inner Four Planets
Made up of rock and metal and have a few to no moons.
Natural Sciences and Technology - Grade 6 5

6. Natural Sciences and Technology - Grade 6
Mercury
Mercury is the closest to the Sun.
It:
- is the smallest planet.
- has no atmosphere.
- has no moons.
- is hot.
- takes 88 days to orbit the Sun.
Visit
DISTANCE OF PLANETS FROM THE SUN
Natural Sciences and Technology - Grade 6

7. Natural Sciences and Technology - Grade 6
Mercury
Mercury has many craters [circular holes].
Its average temperature is 168 ºC.
Distance from the Sun [closest is 46 M km; furthest is 60 million km, average is 57 M km.
Mercury can be observed from the Earth in an event called a transit.
Visit
DISTANCE OF PLANETS FROM THE SUN
Natural Sciences and Technology - Grade 6

8. Natural Sciences and Technology - Grade 6
Venus
Second planet from the Sun.
Named after the Roman goddess of beauty and love.
It has a very thick atmosphere of CO2.
Hottest planet [average surface temperature is 462 °C].
It has no moons nor water.
Natural Sciences and Technology - Grade 6 8

9. Natural Sciences and Technology - Grade 6
Venus
It is about the same size and mass as Earth and named the Earth’s sister planet.
It takes 225 days to orbit the Sun.
It takes 243 Earth days to rotate once on its axis.
It is also known as the Morning Star and the Evening Star.
Natural Sciences and Technology - Grade 6 9

10. Natural Sciences and Technology - Grade 6
Earth
Third planet from the Sun.
Called ‘the blue planet’ [ocean water makes the Earth appear blue from space].
It has one moon.
It takes actually [365¼ = year] days to orbit the Sun [results in leap year every 4th year with 29 days in February].
Natural Sciences and Technology - Grade 6 10

11. Natural Sciences and Technology - Grade 6
Earth
70% of Earth is covered with water.
It takes 23 hours, 56 minutes and 4 seconds to rotate on its axis.
It is not actually round in shape; in fact it is geoid. (Its rounded shape has a slight bulge towards the equator).
Natural Sciences and Technology - Grade 6 11

12. Natural Sciences and Technology - Grade 6
There is 3% fresh water on Earth [2% is frozen in ice sheets and glaciers and only 1% water of the Earth is fresh - in rivers, lakes and underground].
97% water is salted on Earth.
The Earth tilts at an angle of 23.5 degrees as it moves around the Sun.
Earth is 150 million km from the Sun.
Earth
Natural Sciences and Technology - Grade 6 12

13. Natural Sciences and Technology - Grade 6
Earth
Average temperature is 15 °C.
Atmosphere contains oxygen which animals breathe in and carbon dioxide which plants take in.
Natural Sciences and Technology - Grade 6 13

14. Natural Sciences and Technology - Grade 6
Mars
Fourth planet from the Sun.
Called ‘red planet’ because its rocky surface is covered in red dust.
Many volcanic mountains [e.g. Olympus Mons that is 21km high and 600 km in diameter].
It has a thin atmosphere, mostly carbon dioxide.
Natural Sciences and Technology - Grade 6 14

15. Natural Sciences and Technology - Grade 6
Mars
Average temperature is 55 °C.
No surface water - all ice.
Two moons.
320 days to orbit the Sun.
Largest dust storms in solar system.
Natural Sciences and Technology - Grade 6 15

16. Natural Sciences and Technology - Grade 6
Asteroids
There is an asteroid belt between Mars and Jupiter.
It is lumps of rocks that broke away from planets long ago.
Some travel very fast [25 km per second] as it orbits around the Sun.
Different sizes [big as small stones or bigger than a school building].
Gathered in a ring [asteroid belt] in the solar system.
Natural Sciences and Technology - Grade 6 16

17. Natural Sciences and Technology - Grade 6