PH109 Exploring the Universe, test #2, Spring 07

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

1) Why to the orbits of the planets follow a geometrical progression in size?

a) That’s how material was distributed in the solar nebula.

b) gravitational resonances swept material into regions.

c) comets and asteroids collected material between Mars and Jupiter.

d) the solar wind blew gas and dust out of the solar system.

2) This planet lost its designation as a planet:

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

3) 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

4) What affect does the Greenhouse effect have on the surface environment of Venus?

a) Little or no effect.,

b) About the same as on Earth.

c) It has reduced the surface temperature by about 30 degrees Celsius.

d) It has raised the surface temperature by hundreds of degrees Celsius.

5) In light of modern solar system theory, why do the orbits of the planets all lie in nearly the same plane?

a) The Sun's gravity forced them into these orbits.

b) The angular momentum of the solar system was kept to a minimum this way.

c) The early solar nebula flattened into a disk.

d) This happened purely by chance.

6) 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.

7) 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.

8) The dust 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.

9) 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.

10) 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.


11) 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

12) Why is Mars red?

a) Dust storms on the planet have blasted the planet so fiercely that the rocks have reddened.

b) The planet's surface undergoes a process by which rust forms.

c) Sulfuric acid rain etched a reddish color into surface rocks.

d) The ancient volcanoes poured out vast plains of molten red lava which has now solidified.

13) 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

14) 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

15) 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

16) 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.

17) In which part of Saturn's rings do the ring particles move the fastest?
a) the innermost part of the rings, b) the outermost part of the rings
c) in Casssini's division, d) they all move at the same speed

18) 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

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) 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

21) 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

22) 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

23) 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.

24) 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

25) 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, e) never

26) How often does a location on Earth’s Moon experience a "High" tide

a) once per day, b) twice per day, c) once per month, d) twice per month, e) never

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) The clouds of Venus are made mostly of

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

29) 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)

30) 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.

e) the sun emits more infrared radiation than ultraviolet radiation.

31) Which of the Jupiter’s satellites has volcanoes of sulfur

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

32) 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

33) 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

34) 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


35) 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.

36) 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

37) Which planet almost had the name “George”

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

38) 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

39) 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

40) 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