Download Thinking Critically

Thinking Critically
Use the image of Jupiter’s moon Ganymede
to answer the next five questions.
25. INFER Some comets orbit in a direction opposite
to that of the planets. Why might this make
some scientists wonder if they formed with the
rest of the solar system?
26. HYPOTHESIZE Scientists calculate the mass of a
planet from the effects of its gravity on other
objects, such as moons. However, Mercury and
Venus have no moons. What other objects in
space could have been used to determine the
planets’ masses?
A
B
27. COMPARE AND CONTRAST Images of Earth from
space show white clouds above darker land
and water. In what ways are they like and
unlike images of Jupiter?
17. OBSERVE Which crater, A or B, is more eroded?
Explain why you think so.
18. COMPARE AND CONTRAST Describe the differences between the surface in the upper half
of the image and the long, triangular area
near the bottom of the image.
19. INFER Explain which area of the surface, the
smooth part or the heavily cratered part, is
probably older.
20. APPLY The lighter area was produced by
tectonic processes and may have been covered
with molten material. What can you infer
about the inside of this moon?
21. SEQUENCE A crack runs through part of crater
A. Explain how you can tell whether the crack
or the crater formed first. Hint: Think about
what would have happened if the other
feature had formed first.
22. PREDICT Suppose the Moon were hotter inside.
How might its surface be different?
23. IDENTIFY CAUSE Mercury’s surface is not as hot
as Venus’s, even though Mercury is closer to the
Sun. In addition, the night side of Mercury gets
very cold, while the night side of Venus is about
as hot as the day side. Why are the temperature
patterns on these two planets so different?
24. EVALUATE Would it be easier to design a lander
mission for the surface of Venus or the surface
of Mercury? Explain your reasoning.
686 Unit 5: Space Science
Earth
Jupiter
28. ANALYZE Scientists sometimes use round
numbers to compare quantities. For example,
a scientist might say that the Sun’s diameter is
about 100 times Earth’s diameter, even though
she knows that the precise value is 109 times.
Why might she use such an approximation?
29. APPLY Look back at pages 652–653. Think
about the answer you gave to the question
about the large image of a planet and moon.
How would you answer this question differently now?
30. SYNTHESIZE Ice is generally less dense than
rock, which is generally less dense than metal.
Use what you know about materials in the
solar system to estimate whether a moon of
Mars, a moon of Uranus, or the planet Mercury
should be the least dense.
Check your schedule for your unit project. How
are you doing? Be sure that you have placed data
or notes from your research in your project folder.