1. Handout 27-3
The Inner Planets

2. 1 The planets closest to the sun are called the ____________________.
inner planets

3. 2
Name the four inner planets
Mercury
Venus
Earth
Mars

4. 3
The inner planets are also called ______________________ because they are like Earth.
terrestrial planets

5. 4 Describe the composition of the inner planets.
Made mostly of solid rock with metallic cores.

6. 5
Bowl-shaped depressions called _______________________ formed on the surfaces of inner planets when the planets collided with other objects in space.
impacts craters

7. Mercury

8. 6 Mercury, the closest planet to the sun, circles the sun every
B: 88 days

9. 7
Mercury rotates on its axis once every
C: 59 days

10. 8 Mercury’s surface features a long line of cliffs and
B: a large number of craters

11. 9
The absence of a dense atmosphere and Mercury’s slow rotation contribute to
D: a large daily temperature range

12. VENUS
Phases of Venus seen from Earth

13. 10
How long is the orbital period of Venus, the second planet from the sun?
225 days

14. 11
How often does Venus rotate?
Once every 243 days

15. 12
The planet that Venus most resembles in mass, size, and density is ________________________.
Earth

16. 13
Venus’s atmospheric pressure is about ___________ times the pressure on Earth. 90

17. 14 What two factors cause the high temperatures on Venus?
It is close to the sun
High amount of carbon dioxide in its atmosphere

18. 15
What percentage of the atmosphere on Venus is composed of carbon dioxide?
96%

19. 16
Venus appears to be very bright in the night sky because drops of _________________________ form a cloud layer that reflects sunlight.
Sulfur dioxide

20. 17
Why is Venus commonly referred to as the evening star or morning star?
It is usually visible from Earth only in the morning or early evening.

21. 18 The surface of Venus is composed of which two types of rock?
Basalt and granite

22. 19
19. Magellan
B: a U.S. satellite that collected data about Venus

23. 20
volcano
C. a landform commonly found on Venus

24. 21
Maat Mons
A. the highest volcano on Venus

25. Earth

26. 22 Earth is the ________________ planet from the sun.
third (rock from the sun)

27. 23
The orbital period of Earth is ______________ days.
365 1/4

28. 24 Earth completes one __________________ on its axis every day.
rotation

29. 25
How many moons does Earth have?
one

30. 26
Over the last ______________ years, Earth’s continents separated from a single landmass and drifted to their present.
250 million

31. 27 What two factors have caused the surface of Earth to keep changing?
Weathering and erosion

32. 28
Why is Earth the only planet on which water exists in a liquid state?
Earth’s unique atmosphere
Distance from sun allows water to exist in the liquid state

33. 29
How was Earth able to maintain the moderate temperatures that were necessary to support life?
The oceans and atmosphere help Earth to have moderate temperatures.

34. 30
What three elements does Earth have in the proper combination necessary to support life?
Water, oxygen, and temperature

35. Mars

36. 31
Mars is the ____________________ planet from the sun.
fourth

37. 32
How long is Mars’s orbital period?
687 days

38. 33 How often does Mars rotate on its axis?
Every 24 hours and 37 minutes

39. 34 Why are Mars’s seasons similar to Earth’s?
Its axis tilts at nearly the same angle as Earth’s.

40. 35
Mars is believed to have been geologically active because of its massive volcanoes and a system of deep ________________ on its surface.
canyons

41. 36
One of the many major volcanic regions on Mars is called ___________________.
Tharis Montes

42. 37
The largest volcano on Mars is ___________________________, which is three times the height of Mount Everest.
Olympus Mons

43. 38 Why do scientists think that Martian volcanoes have grown so large?
Mars does not have tectonic plates

44. 39
Two seismic wave-producing geological events called _______________________ indicate that volcanoes on Mars may still be active.
mars quakes

45. The End