Noteform: Chapter 3 / Section 3 – The Inner Planets
Name: _____________________________ Section: ______
Directions: Read pages 84 – 91 in your textbook. Fill in the blanks for each question.
1. The four inner planets are small and dense and have rocky surfaces. The inner
planets are often called the ____________________ planets, from the Latin word
that means “Earth.”
2. The Earth has ____ main layers. The _______________ includes the solid, rocky
surface. Under this is the _________________, a layer of hot molten rock. Earth has
a dense core made of mainly __________________ and __________________. The
outer core is __________________ but the inner core is _____________________.
3. Earth is unique in our solar system in having liquid water at its surface. What
percent of the Earth’s surface is covered with water?
____________%
4. Earth has enough gravity to hold on to most gases. Name the gas which makes up
the following percentage of Earth’s atmosphere?
The gas: ____________________ makes up about 20 % of Earth’s atmosphere.
The gas: ____________________ makes up about 80 % of Earth’s atmosphere.
5. _____________________ is the smallest planet and the planet closest to the sun.
This planet was visited in 1974 and 1975 by the probe named ____________________.
This planet has virtually no atmosphere, so at night its heat escapes into space, causing
this planet to have the most extreme temperature range than any other planet.
High temperature on this planet: _____________ degrees Celsius
Low temperature on this planet: _____________ degrees Celsius
6. Name the two planets in our solar system that have no moons.
______________________ and _______________________
7. Venus’s size, mass, density and internal structure are so similar to Earth’s that it is
sometimes called Earth’s:
_____________________.
8. Venus experiences “retrograde rotation.” This means that a very large object may
have struck Venus billions of years ago, causing it to rotate opposite of the other
planets in our Solar System. Venus rotates from:
______________________ to ____________________.
9. One year on Venus is 7.5 Earth months (time for 1 revolution around the sun).
One day on Venus is 8 Earth months (time to rotate/spin around its axis once).
Venus rotates so slowly that its day is longer than its:
_____________________.
10. Venus has a very thick atmosphere, made up mostly of _____________________.
Venus also has a cloud cover made of droplets of: __________________________.
The atmosphere traps in heat in a process called ______________________________.
The __________________probe visited Venus in 1990 and confirmed that Venus is
covered with rock and it’s surface has many volcanoes and plains formed by lava flows.
11. Mars is called the “_______________________.” This color is due to the
breakdown of iron-rich rocks which creates a product called “iron oxide” or
“rust-dust” that covers the surface.
12. The atmosphere of Mars is more than 90 % ___________________________.
Mars has huge canyons, suggesting that Mars once had a large amount of water
which flowed on its surface in the distant past, when Mars was much warmer. Where
is Mars’s water now?
___________________________________________________________________
13. Mars has seasons because it has a ______________________ axis.
14. Name the space probes that landed on Mars in 2004 and found evidence of water:
_______________________ and ______________________
15. Mars has two very small moons named __________________ and _______________