PH109 Exploring the Universe, test#2, Spring 06

Please indicate the best answer to the following questions on the answer sheet provided.

1. The greenhouse effect occurs because

a) carbon dioxide is transparent to visible light and opaque to infrared radiation.

b) carbon dioxide is transparent to infrared radiation and opaque to ultraviolet radiation.

c) ozone is transparent to infrared radiation and opaque to ultraviolet radiation.

d) ozone is transparent to visible light and opaque to infrared radiation.

2. The gas that is most responsible for the greenhouse effect on Earth is

a) oxygen (O2), b) nitrogen (N2), c) carbon dioxide (CO2), d) ozone (O3), e) ammonia (NH3)

3. What produces aurora?

a) chemical reactions in the upper atmosphere, b) meteors

c) collisions of high energy particles with atmospheric gas, d) reflection of Sunlight by high clouds

4. The clouds of Venus are made mostly of

a) water, b) dust, c) CO2, d) Sulfuric acid

5. What is the main constituent of the atmosphere of Venus?

a) Oxygen., b) Nitrogen., c) Hydrogen., d) Carbon dioxide.

6. How often does a location on the Earth experience a "High" tide

a) once per day, b) twice per day, c) once per month, d) twice per month

7. The Roche limit is

a) distance from the Sun where life cannot exist

b) distance from a planet where moons cannot exist

c) the boundary layer between the solar system and the rest of the galaxy

d) the maximum distance a spacecraft can be sent from Earth

8. Which of the following is a consequence of the fact that the rotation and revolution periods of the moon are the same?

a) the moon keeps the same face turned toward the Earth

b) the moon can never be seen from one hemisphere of the Earth

c) all lunar phases can be seen from the Earth

d) there are about 12 months per year

9. This planet's density is so small it could float in a bathtub if you had one big enough.

a) Venus, b) Earth, c) Jupiter, d) Saturn

10. We would have formed a planet, but Jupiter's gravity kept disrupting us.

a) asteroids, b) comets, c) Kuiper belt objects, d) Oort cloud objects

11. Suppose a planet is orbited by a number of satellites. Which of the satellites will feel the strongest tidal forces due to the planet?

a) a large satellite in a close orbit, b) a large satellite in a distant orbit

c) a small satellite in a close orbit, d) a small satellite in a distant orbit

12. Which of the Jupiter’s satellites has volcanoes of sulfur

a) Io, b) Europa, c) Ganymede, d) Callisto

13. We thought this was our sister planet with clouds and such, but we didn't realize it rains sulfuric acid there.

a) Venus, b) Mars, c) Jupiter, d) Neptune

14. Which causes the greatest tidal forces on the Earth

a) alignment of the Planets, b) the Moon, c) the Sun, d) tidal waves in the ocean

15. The many ringlets which compose planetary ring systems are caused by

a) gravitational resonances, b) differences in chemical composition

c) differences in mass density, d) different rotation rates

16. The Cobb family wants to go to the beach during the highest of tides. When should they go?

a) during the first of the month, b) during new Moon phase,

c) during quarter Moon phase, d) anytime is the same

17. One of the following factors, along with temperature, determines whether a body will retain an atmosphere of a given composition.

a) size, b) distance from the sun, c) escape speed, d) rate of rotation

18. What theory of the Moon's origin is favored by most astronomers today?

a) The Moon formed as a separate object near Earth and at about the same time.

b) The Moon formed far from Earth and was captured by its gravity.

c) The Moon originated as material torn from the young molten Earth by centrifugal or tidal forces.

d) The Moon originated as material torn from Earth by the collision of a large Mars-sized body.

19. What causes a meteor shower?

a) Earth crosses the orbit of a comet

b) Earth intercepts a stray swarm of asteroids.

c) Earth encounters the asteroid belt.

d) A small constellation of dying stars disintegrates.

20. What factor caused different planets to form out of different types of material?

a) The angular momentum of the forming planet.

b) The quantity of dust particles in the solar nebula.

c) The variation in temperature throughout the solar nebula.

d) The age of the Sun when the planets formed

21. Cassini's division is

a) a new form of math

b) imaginary line which divides a planet into Eastern and Western hemispheres

c) a gap in Saturn's rings

d) the space between Mars and Jupiter where there is no planet

22. The heat that keeps the interior of Io molten is due to

a) tides, b) radioactive materials, c) frequent meteoroid impacts, d) a large greenhouse effect

23. The flow patterns found on the surface of Mars suggest

a. that Mars is a water-rich world.

b. that the climate on Mars was different in the past.

c. that volcanism is occurring on Mars.

d. that the polar caps are made of water.

24. Which of the solar system objects listed below is most similar to Earth in terms of mass and density?

a. Mercury, b. Moon, c. Venus, d. Mars, e. Deimos

25. Europa has few craters because

a. it is protected from impacts by Jupiter's gravity.

b. it does not have a solid surface.

c. it has erased craters nearly as fast as they have formed.

d. its surface is not strong enough to support craters.

26. The rings of Uranus were discovered

a. during an occultation of a star.

b. during an eclipse of one of the moons by the rings.

c. during an eclipse of Uranus by the rings.

d. as Uranus and the rings passed behind Jupiter.

27. Why does Mars have seasons?

a) Its orbit is circular.

b) It rotates only a few times during each orbit around the Sun.

c) Mars' orbit brings it closer to the Sun during summer and farther from the Sun during winter.

d) Its axis is tilted relative to its orbital plane.

28. How do the escape velocities of the Jovian planets compare to the terrestrial planets?

a) The Jovian planets have much higher escape velocities.

b) There is little variation among the planets.

c) The escape velocities vary greatly from planet to planet,

d) There are no differences between Jovian and terrestrial planets.

e) The terrestrial planets have higher escape velocities

29. Which causes the greatest tidal forces on the Earth

a) alignment of the Planets, b) the Moon, c) the Sun, d) tidal waves in the ocean

30. The gas tail of a comet always

a. trails behind the head along the orbital path.

b. extends ahead of the head along the orbital path.

c. points toward the sun.

d. points away from the sun.

31. The light given off by a comet:

a) is reflected sunlight,

b) is caused by chemical reactions set in place by the intense sunlight

c) due to nuclear energy from the comet's nucleus

d) due to frictional forces in the Earth's atmosphere

32. How do we know the Earth has a liquid core?

a) it sloshes around when the Earth rotates,

b) only compression waves make it through,

c) we have drilled down and sampled some,

d) we can see it at the bottom of some oceans

33. Which planet almost had the name “George”

a) Pluto, b) Uranus, c) Neptune, d) Saturn

34. The rate of cratering on the lunar highlands helps to show that:

a) They are younger than the maria., b) They are older than the maria.

c) They are about 1 billion years old., d) They are about 2 billion years old.

35. Approximately how fast is continental drift moving the continents about with respect to each other?
a) cm per day, b) cm per year, c) cm per century, d) cm per million years

36. This planet almost lost its designation as a planet:

a) Mercury, b) Venus, c) Mars, d) Pluto

37. 99.9% of the Solar system is made of

a) material created by the Big Bang, b) Hydrogen and Helium

c) Oxygen and CO2, d) rocks and nickel/iron cores

38. What accounts for the seasonal changes in the coloration of certain regions on Mars?

a) the covering and uncovering of the regions by dust, b) melting and refreezing of permafrost

c) changes in cloud cover, d) migration of large herds of quadrupeds

39. The main reason the Earth is able to retain an atmosphere is

a) Volcanoes continually out gas and replenish the atmosphere

b) plants continually release oxygen into the atmosphere

c) its gravity is strong enough to hold an atmosphere

d) the ozone causes the greenhouse effect

40. Shepherd moons are

a) moons which shepherd particles into rings

b) moons seen by the shepherds of early times

c) moons which are in orbits opposite of each other

d) the special conditions of our Moon seen in the Fall