Mastering Physics - Astronomy

Rank the Jovian planets from closet to farthest to the sun.

Earth Jupiter Saturn Uranus Neptune

Rank the Jovian planets by average equatorial radius from smallest to largest.

Earth Neptune Uranus Saturn Jupiter

Rank the Jovian planets by their mass from lowest to highest.

Earth Uranus Neptune Saturn Jupiter

Describe the composition, structure, and features found in the atmospheres of Earth and/or Venus

Earth: water vapor cloud layer & oxygen present as a primary component Venus: sulfuric acid cloud layer & carbon dioxide as a primary component Both: atmospheric jet stream & polar vortex (Although Earth and Venus are similar in size, their atmospheres are drastically different. Venus's atmosphere is so thick it hides the planet's surface. The cloud layers contain sulfur, which gives the atmosphere its characteristic yellow hue. Venus's rotation, albeit much slower than Earth's, causes it to have both an upper atmosphere jet stream and polar vortices similar to those seen on Earth. Venus's atmosphere is composed mostly of carbon dioxide; Earth's atmosphere has a substantial amount of oxygen.)

Name the atmospheric gases in order of their abundances for a) Venus b) Earth

a)Venus: Carbon Dioxide (96.5%) Nitrogen (3.5%) Water Vapor (trace) Oxygen (not present) b) Earth: Nitrogen (78%) Oxygen (21%) Water Vapor (0.1-3%)) Carbon Dioxide (0.03%) (The difference in relative percentages of atmospheric components of Venus and Earth results in the vast differences in the planets' atmospheric pressure, density, mass, and temperature)

The percentage of the Earth's surface covered by ocean is about a) 80%. b) 70% c) .85% d) .60%. e) 50%.

b) 70%

If you were on the Moon and you looked up and saw a full Earth, would it be nighttime or daytime on the Moon? a) It would be daytime. b) It would be nighttime.

b) It would be nighttime.

Which of the following statements correctly describes the motion of the particles in Saturn's rings? a) Particles in all the rings hover motionlessly high above Saturn. b) Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings. c) Particles in the inner rings orbit Saturn at a slower speed than particles in the outer rings. d) All the particles in the rings orbit Saturn with the same orbital period.

b) Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings. (In accord with Kepler's third law, particles closer to Saturn orbit at a faster speed than more distant particles.)

When the Sun passes between the Moon and the Earth, we have a) a lunar eclipse. b) met our end. c) a solar eclipse.

b) met our end.

In what region of the Sun is solar energy generated? a) the inner surface b) the inner core c) the mid-interior d) the outer surface

b) the inner core

If Earth didn't spin on its axis but still revolved around the Sun, would the Sun set on the eastern or western horizon or not at all? a) The Sun would set in the west. b)The Sun would set in the east. c) not at all

b)The Sun would set in the east.

Lunar phases refer to question (#24)

(Remember that "waxing" phases mean on the way to full moon and "waning" phases mean after full moon. So if tonight is a waxing gibbous moon, then we are headed toward full moon in about three to four days. Because the full moon is not shown, we'd next see a waning gibbous moon, then a third-quarter moon, and then a waning crescent. From there we'd have new moon (which isn't shown), then the waxing crescent, and then first-quarter. Finally, a full four weeks from now (actually 29 1/2 days), we'd once again have a waxing gibbous moon.)

Vocabulary in Context: Describing Eclipses of the Sun and Moon

1. A solar eclipse that occurs when the new moon is too far from Earth to completely cover the Sun can be either a partial solar eclipse or a(n) annular eclipse. 2. Anyone looking from the night side of Earth can, in principle, see a(n) total lunar eclipse. 3. During some lunar eclipses, the Moon's appearance changes only slightly, because it passes only through the part of Earth's shadow called the penumbra. 4. A(n) total solar eclipse can occur only when the Moon is new and has an angular size larger than the Sun in the sky. 5. A partial lunar eclipse begins when the Moon first touches Earth's umbra. 6. A point at which the Moon crosses Earth's orbital plane is called a(n) node.

Starting with the hypothesis that a planet near Uranus was the cause of the orbital discrepancy, scientists had to develop a plan to find the unidentified planet. They started with what they knew about the discrepancies in the orbit of Uranus. Rank the steps in the order that scientists would take to discover the planet from first to last

Calculate the mass, orbit,and likely position of the unidentified planet. Use optical telescope to search a region of the sky where the unidentified planet is predicted to be. Compare current observations to existing star charts to locate any new objects. Make continued observations to determine if the new object changes position relative to background stars. (Knowing the discrepancy between Uranus's predicted and actual orbit, scientists and mathematicians were able to calculate the mass and orbit of a potential planet beyond Uranus that could cause such a discrepancy. Then astronomers predicted the planet's location in its orbit and began observing the sky for visual evidence of the planet. Once he had accurate star charts to work from and predictions of Neptune's location, it took Johann Galle about 30 minutes to find Neptune!)

Because planets in our solar system are much closer to Earth than even the closest stars, it is easier for us to observe planetary motion relative to the background stars. The diagrams show a sequence of observations over six nights. Examine each labeled object (a-d) one at a time and note if its position changes relative to the objects around it from one diagram to the next. This will give you a clue as to which is a star and which is a planet. (#14)

The diagrams illustrate how Herschel observed the same portion of night sky over several consecutive nights. He observed an object dim enough to be a star, but unlike the stars in the background, this object's position changed from night to night. It moved too slowly to be a nearby comet. Therefore, the object must, instead, be a large body orbiting the Sun quite distant from Earth. Quite accidentally, he had discovered a new planet, which was later named Uranus.

Venus vs. Earth (#8) a) atmosphere b) troposphere c) surface pressure d) surface temperature

Venus > Earth Venus > Earth Venus > Earth Venus > Earth (The atmospheres of Venus and Earth differ greatly in temperature, altitude, and pressure. Venus's extremely high surface temperature is hot enough to melt lead. Venus's atmosphere has a higher altitude and density than Earth's, resulting in a surface pressure that is approximately 90 times greater than on Earth.)

How many known planets are in our solar system? a) 8 b) 9 c) 10 d) 5

a) 8

Which body in the solar system has the highest level of volcanic activity? a) Io b) Earth c) Mars d) Jupiter

a) Io

What dwarf planet was downgraded from planetary status in 2006? a) Pluto b) Sedna c) Ceres d) Vesta

a) Pluto

How are the outer planets different from the inner planets, aside from their locations? a) The outer planets are large, rich in gas, and have many rings and satellites. b) The outer planets are small and made of silicate rock. c) The outer planets are small, made of ices, and have many satellites. d) The outer planets are large, made of ice, and have many rings and satellites.

a) The outer planets are large, rich in gas, and have many rings and satellites.

Characteristics of the atmospheres of a) Venus b) Earth c) Mars

a) Venus runaway greenhouse effect sulfuric acid clouds almost no wind b) Earth atmosphere composed primarily of nitrogen ultraviolet-absorbing stratosphere c) Mars global dust storms extremely low density atmosphere (Be sure to recognize that Venus has very little wind because of its slow rotation rate. Venus suffered a runaway greenhouse effect because of its distance from the Sun; If Earth were placed at the same distance, our planet would suffer the same fate. Earth has an ultraviolet-absorbing stratosphere because of the oxygen in the atmosphere, which at high altitudes forms molecules of ultraviolet-absorbing ozone.)

In what alignment of the Sun, the Moon, and Earth does a lunar eclipse occur? a) When all three are aligned with the Earth between the Sun and Moon. b) When all three are aligned with the Moon between the Sun and Earth.

a) When all three are aligned with the Earth between the Sun and Moon.

In what alignment of the Sun, the Moon, and Earth does a solar eclipse occur? a) When all three are aligned with the Moon between the Sun and Earth. b) When all three are aligned with the Earth between the Sun and Moon.

a) When all three are aligned with the Moon between the Sun and Earth.

With daytime temperatures that can reach 430°C, why is nighttime on Mercury so cold? a) With very little atmosphere, heat is quickly lost back into space. b) The solar winds quickly dissipate all heat on the planet's dark side. c) The weak gravitational field doesn't retain the daytime's heat. d) Because the year is so short, there isn't enough time for the heat to build up in the equatorial regions.

a) With very little atmosphere, heat is quickly lost back into space.

Compared to the density of water, the density of Saturn is a) less. b) more. c) about the same.

a) less

Saturn's rings look bright because __________. a) light from the Sun reflects off the material in the rings b) the material in the rings is hot and creates its own light c) light from Saturn reflects off the material in the rings

a) light from the Sun reflects off the material in the rings (Saturn's rings look bright because icy particles in the rings reflect (scatter) sunlight.)

The smallest planet in our solar system is _______. a) Mercury b) Europa c) Mars d) the Moon

a)Mercury

When the Moon assumes its characteristic thin crescent shape, the position of the Sun is a) almost directly behind the Earth, so Earth is between the Sun and the Moon. b) at right angles to the line between the Moon and Earth c) .almost directly in back of the Moon.

c) .almost directly in back of the Moon.

When we see a half-moon, the position of the Sun is a) almost directly behind the Earth. b) almost directly behind the Moon. c) at right angles to a line from Earth to the Moon. c) about 45° from a line from Earth to the Moon.

c) at right angles to a line from Earth to the Moon.

Saturn's rings are composed of __________. a) gas from the early solar system b) a series of solid concentric circles c) lots of individual particles of ice and rock d) parts of Saturn's upper atmosphere being vented into space

c) lots of individual particles of ice and rock (Although Saturn's rings appear solid when viewed from Earth, they are actually made of countless icy particles ranging in size from dust grains to small boulders.)

The number of moons in orbit around Mars is a) zero. b) one. c) two. d) three.

c) two.

The predominant gas in the atmosphere of Earth is a) water vapor. b) methane. c) oxygen. d) nitrogen. e) carbon dioxide.

d) nitrogen

After the discovery of Uranus, astronomers calculated its orbit and predicted its position in the sky using Kepler's laws of planetary motion, which had been known since the early 17th century. However, they soon discovered a small discrepancy between the predicted and actual positions of Uranus. As a scientist, what should you do when presented with such a conflict between prediction and observation? a) consider that Uranus may not be a planet b) consider whether Kepler's laws need to be modified to account for the new observations c) verify that your observations are correct d) think about what else might cause the observed discrepancy Submit e) all of the above

e) all of the above (Scientists must consider many possibilities when presented with unexpected evidence such as the discrepancy between the predicted and actual locations of Uranus. They must verify that their observations are correct. If the observed discrepancy is confirmed, then scientists should consider whether existing laws need to be modified or if there is an unidentified or unknown cause of the discrepancy. Scientists may also need to consider if they need to reevaluate whether or not Uranus is indeed a planet. In this case, the most likely explanation seemed to be that there was another planet beyond Uranus affecting the orbit of Uranus. A search began for another planet.)