What Is (Are) the Major Source(S) of Tides on Earth

PH109 Exploring the Universe, Test #2, Fall, 1999

Name______

Please indicate he best answer to the following question on the answer sheet provided. Please answer the essay question on this copy of the test. All questions are worth 2 points unless noted otherwise.

1) What is (are) the major source(s) of tides on Earth? a) Moon only, b) Moon and Sun, c) Moon, Sun, and Jupiter, d) Moon and other planets

2) 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

3) 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

4) 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

5) Sea-floor spreading and continental drift are believed to be caused by which of the following? a) tides, b) convection currents in the mantle, c) changes in the Earth's magnetic field, d) shrinkage of the crust as the Earth cools

6) 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

7) What produces aurorae? 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

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) The surface of the moon a) at one time had running water, b) has changed little in the past 2-3 billion years c) has an atmosphere similar to the Jovian planets, d) acquired its present appearance about 100 million years ago 10) How can craters tell us about the ages of surface regions of planets? a) crater density increases with time b) material blasted from the craters sometimes reaches Earth and can be dated c) craters shrink in size at a predictable rate d) impacts produce carbon 14, which can be dated

11) The surface temperature of Mercury is high primarily because of a) solar heating, b) a large greenhouse effect, c) volcanic activity, d) frequent meteoroid impacts

12) Why is the daily temperature variation on Mars so much larger than we experience on Earth? a) Mars spins slowly, so its nights are very long b) Mars is much darker than the Earth, so it absorbs more Sunlight c) Mars' atmosphere is too thin to insulate the surface d) Mars has smaller internal heat sources than the Earth has

13) 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

14) The images transmitted by one of the Viking landers showed frost during the Martian winter. What was the frost made of? a) water, b) methane, c) ammonia, d) carbon dioxide

15 ) The most massive planet in our solar system is a) Earth, b) Jupiter, c) Mercury, d) Venus

16) 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

17) Which of the following planets was almost named George? a) Jupiter, b) Saturn, c) Uranus, d) Neptune

18) Why are no impact craters seen on the moon Io? a) it does not have a solid surface, b) it has extensive volcanic activity c) it was very recently captured by the solar system, d) its icy surface heals very rapidly

19) 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

20) 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

21) Where in the Solar system are you most likely to find planets with rocky mantels and nickel and iron cores? a) inner parts of the Solar system, b) outer parts of the Solar system c) near the planet Jupiter, d) with equal probability anywhere

22) On which planet is it possible to see seasonal changes in the polar ice caps and coloration changes on the rest of the planet? a) Mars, b) Jupiter, c) Venus, d) Saturn 23) The rings of Saturn are made up of thousands of smaller ringlet systems which are caused by a) rings formed, just like the planets, at different distances from their source b) the magnetic fields separates them into smaller rings c) the gravitational fields of the many moons d) asteroid collisions

24) Which is the smallest planet in the Solar system a) Pluto, b) Mercury, c) Venus, d) Mars

25) Which planet is most likely to be hit by a comet or an asteroid a) Earth, b) Mars, c) Jupiter, d) Saturn

26) 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

27) What is the primary ingredient in the Earth's atmosphere? a) Nitrogen, b) Oxygen, c) Nitrogen and oxygen in equal amounts., d) Hydrogen, e) Carbon dioxide

28) 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

29) The presence of a magnetic field on Mercury is surprising because: a) The planet is low in iron., b) The planet rotates so slowly. c) Planets rarely have magnetic fields., d) The planet is so close to the sun

30) The lack of a magnetic field on Venus probably stems from the planet's: a) Nearness to the Sun., b) Extremely thick atmosphere. c) Slow rotation., d) High surface temperatures.

31) 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, there are no differences between jovian and terrestrial planets. d) The terrestrial planets have higher escape velocities

32) What is the order of the four Galilean moons of Jupiter in increasing distance from the planet? a) Ganymede, Callisto, Io, Europa, b) Callisto, Io, Europa, Ganymede c) Io, Europa, Ganymede, Callisto, d) Europa, Ganymede, Callisto

33) What is Io's atmosphere made of? a) sulfur dioxide, b) methane, c) ammonia, d) nitrogen

34) What is the ultimate fate of Hydrogen released into the Earth's atmosphere a) it will combine with Oxygen to form water, b) it is absorbed by plants during photosynthesis a) it combines to form ozone, d) it escapes into space 35) 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

36) The length of the Mercury year is a) 365.25 Mercury days, b) 1/2 Mercury day, c) equal to its rotation period, d) constantly changing

37) The rotation of Venus a) is in the retrograde direction, b) constantly changes c) has always been fixed, d) takes about 1 1/2 Venezian years to complete

38) An astronomical unit is a) the distance between the Sun and Earth b) the distance between the Earth and the moon c) the angle between opposite sides of the Sun d) the angle between the Sun and the nearest star e) the distance between the Sun and the nearest star

39) Which of the following planets, at the same distance from the Sun, would be the coolest? a) poorly reflecting in the visible, radiates well in the infrared b) poorly reflecting in the visible, radiates poorly in the infrared c) highly reflecting in the visible, radiates poorly in the infrared d) highly reflecting in the visible, radiates well in the infrared

40) Eclipses do not occur each month because a) the moon is always in the ecliptic b) the moon's orbit is eccentric c) the moon's distance to the Earth keeps changing d) the moon's orbital plane is inclined (tilted) to the ecliptic plane 41) (10 points) Explain why a massive, cool planet is more likely to have a thick atmosphere than is a less massive, hot planet.

42) (10 points) Explain the Greenhouse effect here on Earth. Identify which gass(es) is(are) involved.