1. The Solar System: Inner Planets

2. What is a planet?
A planet is a body of matter that travels around a star in a fixed path called an orbit.
Planets don’t give off their own light…they reflect the light of the Sun.

3. Planets are classified as inner planets and outer planets
Mercury
Venus
Earth
Mars
Outer
Jupiter
Saturn
Uranus
Neptune
Pluto

4. THE INNER PLANETS A.K.A Terrestrial Planets- Earth Like
All composed of a solid rock surface
If we had the proper technology, we could travel across these planets collecting samples

5. MERCURY

6. Mercury is the closest planet to the sun.
Mercury is only about one-third the
size of Earth
It is smaller than any other planet
except Pluto
Year lasts 88 days (revolution)
It takes 59 Earth days for one
complete rotation

7. Lack of Atmosphere
Because it is so close to the sun, Mercury has no atmosphere
Therefore, it has no weather
Temps. During the day can be 427 degrees Celsius (800 degrees F.) and fall during the night to -170 degrees Celsius (-274 degrees F.)

8. Craters on Mercury U.S. Space Craft, Mariner 10, flew past Mercury in
1975
Landscape is covered with craters from material
striking the planet

9. VENUS

10. Venus is the second planet from the sun
Has a similar diameter, mass, and density as Earth-
Thus Venus is known as Earth’s Twin!
They differ in that Venus does not have oceans or
human life
Also, it’s temp. reaches 484 degrees Celsius
(903 degrees F.)
In 1975, two Soviet Space Craft landed on Venus and
were destroyed within hours due to harsh
atmospheric conditions

11. Way Too Much Atmosphere!
Thick blanket of dense clouds high up in the planet’s atmosphere
These clouds contain sulfuric acid which gives them a yellowish color
Beneath this cloud layer is a layer of Carbon Dioxide Gas
This gas is much denser than the nitrogen and oxygen that makes up our atmosphere on Earth

12. DO YOU HAVE ANY IDEAS WHY VENUS GETS SO HOT?

13. It’s so hot because……
Carbon Dioxide traps the heat and causes the greenhouse effect. It acts like the glass in a green-house and traps all the heat inside.

14. More Facts Sixth largest planet
It rotates opposite of all other planets- clockwise
The Venusian day takes 243 Earth Days
The Venusian year lasts 224 Earth Days

15. Temperatures can reach 484 degrees Celsius (903 degrees F.)!
Highest temperature on Earth has been 58 degrees Celsius (136.4 degrees F.)
RADAR picture
Blue=smooth
Brown =rough

16. EARTH

17. Third Planet from the sun
Fifth Largest Planet
Only planet known to support life
Surface contains 70% water and 30% land
Atmosphere is 78% nitrogen, 21% oxygen, and 1% argon
Water exists in all three states of matter

18. It takes 24 hours to rotate around the axis- which equals one day
It takes 365 days to revolve around the sun
It has one satellite- the moon

19. MARS

20. Mars is the 4th planet from the sun
228 million km from sun
Seventh largest planet
In 1976 Viking 1 and Viking 2 probes landed on mars to give us important new information on the atmospheric conditions and rugged landscape

21. The Martian atmosphere is very thin, and solar winds carry it
Away because Mars has a weak gravitational and magnetic field
The Martian soil is coated with a reddish compound also known
as rust...can you guess what this compound would be?
Surface covered by rocks and soil
The surface of Mars is very cold: A high temp. may reach
-20 degrees Celsius (-4 degrees F.) to a low of -140 degrees
Celsius (-220 degrees F.)

22. Olympus Mons Largest known volcano in the solar system
3 times taller than the
tallest mountain on Earth
Base would stretch from
Washington D.C. to
Boston
Volcanoes are dormant
or inactive

23. Valles Marineris
Valles Marineris is Mars’ largest canyon. If placed on Earth,
It would stretch from New York City to Los Angeles

24. Why is there no life on Mars?
The Earth’s ozone layer absorbs harmful UV rays from the sun
Mars has no ozone.
It lacks the simplest molecules because they can’t survive the UV rays

25. Earth sounds pretty nice right about now, doesn’t it?