Download Webquest – Answer Key

Webquest - Inner vs. Outer Planets – ANSWER KEY
Directions Go to: http://www.enchantedlearning.com/subjects/astronomy/planets/ and answer the
questions below.
1. List the 5 main things that make up our Solar System:
a. Sun
b. Eight planets
c. Moons
d. Asteroid belts
e. Comets and meteors
2. List the 9 planets in order from the sun.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto (dwarf planet)
3. What lies in between Mars and Jupiter? An asteroid belt
4. Look at the diagram of the relative sizes of planets.
Which planet is the largest? Jupiter.
Which planet is the smallest? Mercury.
Which planet is so large all the other could fit inside of it? Jupiter
The 9 planets are split into 2 groups: “terrestrial: rocky and Earth-like” and “jovian: gassy and Jupiterlike” and Pluto is considered the “oddball.”
5. List the terrestrial (inner) planets Mercury, Venus, Earth, Mars.
6. List 3 the characteristics of the terrestrial (inner) planets.
a. Relatively small
b. Composed of mostly rock
c. Has few or no moons
7. List the Jovian (outer) planets Jupiter, Saturn, Uranus, Neptune, Pluto (dwarf planet)
8. List 4 characteristics of the Jovian (outer) planets
a. Huge
b. Gaseous
c. Ringed
d. Many moons
9. Why is Pluto not considered a Jovian planet : because it's a dwarf planet and it's rocky with four
moons.
10. What happens to the temperature of a planet as they get farther from the sun? They get cooler.
Use the chart “The temperature of the Planets” to answer the following questions:
11. What is the hottest planet? Venus. Approximate temp. 832 oF 450 oC
12. What is the coolest planet? Uranus Approximate temp. 408 oF 250 oC
13. Which planet/planets could liquid water exist on? Earth, Mercury, Venus
Use the section “The density of the Planets” to answer the following questions:
14. Why are the outer planets less dense than the inner planets? The outer planets are less dense
because they don't have water on them and the rocky planets tend to have more water. Also, the outer
planets are made of gas as well, and gas is less dense than rock.
15. List the 2 planet that have the greatest density? Earth and Mercury.
Are they inner or outer planets? inner.
16. Why are the outer planets less dense than the inner planets? The outer planets are less dense
because they don't have water on them and the rocky planets tend to have more water. Also, the outer
planets are made of gas as well, and gas is less dense than rock.
Use the section “The mass of the Planets” to answer the following questions:
17. List the 4 most massive planets (largest to smallest)?
a. Jupiter
b. Saturn
c. Neptune
d. Uranus
18. Are they inner or outer planets? outer.
19. Why do you think they are so massive? They are big gas giants. Gas expands and takes up more
room, making the gas giants bigger.
Use the section “Gravity on the Planets” to answer the following questions:
20. What planet has the largest gravitational attraction? Jupiter
21. What 4 planets have similar gravitational attraction as earth?
a. Saturn
b. Uranus
c. Neptune
d. Venus
22. Why do you think earth has the same gravitational attraction as such large gas planets?
The bigger the mass the more gravitational force a planet has.
Use the section “A day on each Planets” to answer the following questions:
23. What makes a day on a planet? The length of time it takes a planet to rotate on its axis.
24. Which planet has the longest day? Venus, how long is it? 243 Earth days
25. Which planet has the 2nd longest day? Mercury, how long is it? 59.9 days
26. Which planet has the shortest day? Jupiter, how long is it? 9.8 Earth hours.
27. Look at the inner planets are their days long or short as compared to the outer planets? The inner
planets have longer days than the outer planets.
Use the section “Average orbital speed of a planet” to answer the following questions:
28. What happens to the speed a planet travels when it is closer to the sun? Goes faster
Further from the sun? Goes slower
29. What planets spin the fastest? Mercury, Venus, Earth and Mars
30. Are they inner or outer planets? They are all inner planets.
31. What is the speed of the fastest planet? 29 m/s. the slowest planet? 3 m/s.
Use the table “Average orbital speed of a planet” to answer the following questions:
32. How many moons does Pluto have? 4. Why isn’t it listed above with the gas planets? Because it is a
rocky and a dwarf planet that doesn't contain any gas.
33. Look at the temperatures of the planets in oK. What pattern do you see? The closest planets to the
sun usually have a higher temperature with the exception of Venus having a higher temperature than
Mercury.
34. A planet’s rotation period is? the length of its one planetary day which is the time it takes a planet to
rotate.
35. Which planets have rotation periods of less than 24 hrs? Jupiter, Saturn, Uranus, Neptune
36. Which planets have rotation periods of more than 24 hrs? Mercury, Venus, Mars
37. A planet's revolution period is? the length of its one planetary year which is the time it takes for a
planet to rotate the sun.
38. Which planets have revolution periods of less than 2 years? Mercury, Venus, Earth, Mars
39. Which planets have revolution periods of more than 2 years? Jupiter, Saturn, Uranus, Neptune
40. Do astronomers think that there is a tenth planet? Yes
What do they think it might be? a companion/dwarf star, named Nemisis.