Astronomy final S1
11.5 Oblateness= (D maximum - D minimum)/(D maximum) 5. Enceladus Mass=1.2 x 10^20 kg Dimensions=512 x 494 x 489 km Oblateness=
Oblateness=.044
11.6. Mimas Mass: 3.81 x 10^19 kg Dimensions 416 x 393 x381 km Oblateness=
Oblateness=.27
6.2 Why is Mercury basically airless?
Outgassing from the crust and particles captured by the solar wind.
15.4 The plot in Figure 15.18 shows the changes in the brightness of a star caused by the transit of two different planets orbiting this same star. Which one of the two planets is larger? (Both plots are on the same scale). Explain.
Planet A is larger, since it causes a larger drop in brightness of the star. Larger objects block more light, causing the star to become dimmer.
2.3 On which days of the year do day and night have equal duration?
Spring and fall equinoxes
2.4 On which days of the year does the Sun rise exactly in the East and set exactly in the West?
Spring and fall equinoxes
13.2 What evidence is there that Triton has been geologically active in a relatively recent past? a) Few impact craters. b) Dark smudges that indicate nitrogen geysers activity. c) Round basins that appear to have been flooded a few times. d) All of the above.
D
8.37 Explain the effects of tides on the length of Earth's day. Were days longer or shorter in the past.
Days were shorter in the past and they are still getting longer. The tides cause friction with the sea floor which slows the rotation of the earth making days longer around 1 hour every 200 million years.
15.1 Few planets have been discovered by direct imaging. Why is it so hard to detect the light of an exoplanet? a) Because exoplanets are too far away. b) Because exoplanets are very small. c) Because host stars are bright. d) Because exoplanets are very rare. e) Because exoplanets are very dim objects very close to very bright objects.
E
15.6 As of November 2013 the number of exoplanet candidates found by the Kepler's mission totaled 3,538. Candidates require confirmation, or follow up observations to verify they are actually planets. Figure 15.20 shows the distribution of exoplanet candidates according to their sizes. What percentage of all candidate planets detected by Kepler were found to be Earth size? What percentage were super Earths, Jupiter size, and Neptune size?
Earths: 19.05% (674/3538 x 100); Super Earths: 30.41% (1076/3538 x 100); Jupiter Size: 6.47% (229/3538 x 100); Neptune size: 41.19% (1457/3538 x 100)
2.9 Figure 2.23 and 2.24 show images of the northern horizon at two different locations. Which one is from a location closer to the equator? Explain
Figure 2.32 is from a location closer to the equator because the north celestial pole is closer to the horizon, and more stars appear to rise and set
10.3 What observational evidence supports the idea of a liquid ocean of water underneath the icy surface of Europa?
In Earth's arctic and Antarctic region during the spring, the ice breaks up forming ice blocks that drift. Similar ice rafts are found on Europa which suggest a liquid ice layer for the blocks to float. More evidence is magnetic field measurements made by Galileo spacecraft. Jupiter's magnetic field induced electric currents in Europa. Detection of the weak magnetic field means that an electrically conducting liquid exists, which suggest a possible underground water ocean.
10.4 If Io is about the same size as the moon and the moons interior has mostly cooled then why hasn't Io cooled? What causes the volcanic activities on Io?
Io's intense volcanic activity is driven by tidal heating. As Io revolves around Jupiter, the gravitational tugs of the other Galilean Moons cause slight variations in the distance between Jupiter and Io (it affects the eccentricity of Io's orbit). These variations result in tidal stresses that squeeze and flex the moon, generating heat through friction.
7.6 If Venus and Earth obtained their primordial atmospheres from their volcanic activity and their water, in part, by impacts with icy bodies, why is Venus a dry planet? Was Venus dry in the past? What happened to the water?
It has the runaway greenhouse effect. All of the water evaporated and it got hotter and hotter. There used to be liquid water.
2.10 Figure 2.25 shows a picture of the northern horizon taken from the Netherlands. Estimate the length of the exposure and explain how you got your answer.
It will take 23 hours and 56 minutes since that is how long a sidereal day takes. The trails in the figure 2.25 are small and correspond to about one hour exposure. This can be measured directly using a protractor to measure the angular distance of any one of the star trails, and remembering that a complete circle is 360 degrees. Each star will move 15 degrees in an hour.
7.1 Why do astronomers think that the surface of Venus is geologically young (only 500 million years old)?
There are too few craters, and the surface appears to be recently resurfaced.
5.5 The Sun's total mass is equal to 2x10^30 kg. The Sun uses about 600 billion kilograms of hydrogen each second. Even though 75% of the Sun's mass is hydrogen only about 13% of this hydrogen is available for fusion in the core. a. how much hydrogen does the Sun fuse in a year? b. how much hydrogen does a star like our Sun have (in kilograms)? c. how much hydrogen available for fusion does a star like our Sun have (in kilograms)? d. for how long can a star like the Sun last: in other words, how long does it take for the energy supply of Hydrogen in the core to run out?
a. The sun fuses 1.9x10^10 kilograms of hydrogen per year. b. Our sun has 1.5x10^30 kilograms of hydrogen c. 1.95x10^29 kilograms d. About 10 billion years
12.6 Which spacecraft has explored the Uranus system? a. Voyager 2 - sent to study the outer planets, including Uranus b. Galileo - studied Jupiter, its moons, and other planets c. New Horizons - studies deep space past Pluto d. Voyager 1 - mainly Jupiter and Saturn, and Voyager 2 e. All of them.
a
4.4. The solar nebula formed a protoplanetary disk around the protosun because: a) of conservation of angular momentum. b) it is easier to form planets if the material is in a disk. c) the primordial solar nebula had a disk shape. d) All of the above. e) None of the above.
a
7.5 Which of the following are greenhouse gases? a. All b. Co2 and water, but not methane c. Co2
a
9.4 Mars' diameter is half of Earth's diameter. a. How does the volume of Mars compare to the volume of Earth? Compare their masses as a ratio b. How does the surface area of Mars compare to Earth's surface area? Compare their surface areas as a ratio c. By how many times is the ratio of the surface area to the volume of Mars larger than the ratio of the surface area to the volume of Earth?
a. Earth: 259874004352 mi^3 Mars: 39125843175 mi^3 It has a 1:5 ratio b. Earth: 196936410 mi^2 Mars: 55734819 mi^2 It has a 1:4 ratio c. Earth ratio: 1320 (Volume/Surface area) Mars ratio: 702 (Volume/Surface area)
5.6 CME's can blast billions of tons of gas and travel at speeds over 3 million km/h: a. IF it was aimed toward Earth, how long would it take for the particles of the bubble to arrive at Earth? (Recall the Earth-Sun distance = 150,000,000 km). b. Compare the speed with a fast jet plane (600miles/h) and the space shuttle (28000 km/h). Can the space shuttle out-race the bubble? (1km=0.6 miles).
a. It would take 50 hours to reach us. (150 million km / 3 million km/h = 50 hours) b. The jet plane is about 28.997 times slower(600mph = 965.606kph 28000kph / 965.606kph = 28.997; no, not even close
1.4 For a planet to sweep out equal areas in equal amounts of time a) it has to move slower when closer to the Sun. b) it has to move around the Sun with uniform speed. c) it has to move faster when closer to the Sun. d) none of the above.
c
10.2 The two outermost Galilean moons differ from the innermost ones by having a. Much higher average densities b. Same densities but younger less cratered surfaces c. Much lower average densities d. Same densities but older heavily cratered surfaces.
c
12.2 Radical seasons on Uranus are due to: a. Uranus' eccentric orbit b. Misaligned magnetic field axis c. Highly tilted rotation axis d. Long orbital period e. All of the above
c
13.1. Neptune's rings are: a) narrow, bright, and are named after astronomers who contributed to the planet's discovery. b) wide, dark, and one of them has a clumpy structure. c) dark, narrow, and are named after astronomers who contributed to the planet's discovery. d) clumpy, dense, and wide. e) bright, narrow, and one of them has a clump structure.
c
15.2 What types of planets are easier to find when using the radial velocity technique? a) Planets more massive and more distant from the host star. b) Planets less massive and less distant from the host star. c) Planets more massive and less distant from the host star. d) Planets less massive and more distant from the host star. e) None of the above.
c
2.1 The seasons of the year are caused by: a) differences in the distance from the Sun as Earth orbits in an elliptical path. b) differences in the distance of the northern and southern hemispheres from the Sun. c) the tilt of the Earth's axis. d) all of the above. e) none of the above.
c
4.5. Which one is true about the condensation process during the Solar System's formation? a) Metals and rocks condensed only in the inner regions. b) Volatiles condensed only in the inner regions. c) Metals and rocks condensed both in the inner and outer regions. d) Volatiles condensed both in the inner and outer regions. e) None of the above.
c
6.9 Why doesn't the Moon have prominent lobate scarps like Mercury does? a) The Moon likely shrunk as it cooled, just like mercury. However the scarps have not been found yet. b) The Moon shrunk as it cooled like Mercury. However it shrunk when the crust was still molten and did not form the scarps. c) The Moon did not shrink as much as Mercury did as it cooled. The Moon's core is much smaller and its interior is mostly rock. Rocks do not shrink as much as metals when they cool.
c
1. 1 The ancient Greeks thought that the Earth was stationary because a) they did not feel Earth move, so it was contrary to their senses to imagine Earth moving. b) they reasoned that if Earth moved it would lose its atmosphere. c) they did not detect any stellar parallax. d) All of above. e) None of the above.
d
1. 5 What is a property of ellipses? a) Ellipses have two foci. b) Eccentricities go from 0 to less than 1. c) The sum of the distances from any point to the foci is a constant. d) All of the above. e) None of the above
d
10.1 Which of the following is true about the Great Red Spot? a. It has been observed for more 5 centuries b. It rotates clockwise. c. It is stable and doesn't change in shape or size d. It is the largest storm ever observed in the planets
d
11.2 Belts and zones are less visible on Saturn as compared to Jupiter because: a. They have a different chemical composition b. They are affected by Saturn's magnetic field. c. Saturn is father away from Earth d. They lie deeper down in the atmosphere and are covered by a layer of methane haze. e. All of the above.
d
12.4 An observer on Uranus's south pole would see the sun during : a. Summer for the northern hemisphere b. The spring c. The spring and fall D. Winter for the northern hemisphere E. None of the above
d
2.2 The shortest day of the year for the northern hemisphere is: a) spring equinox. b) summer solstice. c) fall equinox. d) winter solstice. e) none of the above.
d
3.4 Adaptive Optics is a technique that: a. improves the image by combining the image of many telescopes. b. magnifies the image. c. makes the image brighter allowing astronomers to observe fainter objects. d. improves the image by removing the atmospheric blurring. e. corrects chromatic aberration.
d
4.1. The solar nebula theory explains: a) why all the planets orbit in nearly the same plane. b) why all the planets orbit the Sun in the same direction. c) why there are physical distinctions between groups of planets. d) All of the above e) None the above.
d
4.2. Why are the giant planets much larger than the terrestrial planets? a) Because there was more material in the outer disk. b) Because the outer disk was more dense. c) Because they are composed of ices which are less compact than metals and rocks d) Because water, methane and ammonia were much more abundant in the solar nebula and these planets had enough gravity to hold gases such as hydrogen and helium. e) None the above.
d
8.28 An annular solar eclipse occurs instead of a total solar eclipse when a. The moon's orbit is tilted with respect to earths orbit around the sun b. The sun is slightly larger during the new moon c. The moon is closer to the earth d. The moon is farther from the earth e. None
d
12.1 Which molecule or atom is responsible for Uranus bluish color? a. Molecular Hydrogen (H2) b. Helium c. Ammonia (NH3) d. Water (H2O) e. Methane (CH4)
e
3.5 What can astronomers learn about an object by studying its spectrum
Objects temperature, chemical composition, abundances and motion
9.2 If the composition of the Martian atmosphere is very close to the composition of Venus' atmosphere, why did Venus experience an extreme greenhouse effect while Mars did not? Explain.
Venus is about the same size as the Earth and much closer to the Sun than Mars. Mars did not have enough gravity to retain its atmosphere. Since most of its atmosphere was lost to space, its current atmosphere is too thin to produce a noticeable greenhouse effect.
7.3 What is the evidence for recent volcanic activity on Venus?
Venus shows some materials outgassed by volcanoes (sulfur compounds) and new volcanic outflows
14.3 a) Meteor Crater in Figure 14.27 is a relatively young terrestrial impact crater. It was formed by an iron rich meteoroid of about 50 meters across that impacted about 50,000 years ago in Arizona. The crater's diameter is about 1.19 kilometers (0.74 mi). How many times larger than the meteor is the crater's diameter? b) The meteor struck the ground at a speed of about 20 km/s. Its estimated mass was 270,000,000 kg. The energy of the impact is given by the kinetic energy of the impactor: KE = (m x v2)/2 where KE is the Kinetic energy m is the mass of the impactor v is velocity or ground speed Calculate KE (use kg for mass and m/s for velocity). c) Which would produce a larger crater? Explain your choice. 1) a meteor X with twice the mass and the same veloc-ity as the Meteor crater impactor. Credit: NASA, National Map Seamless Server Figure 14.27 Meteor Crater in Arizona desert. 2) a meteor Y with the same mass and twice the velocity as the Meteor Crater impactor. 3) both meteors X and Y
(a) please explain what you did in a few sentences so others can follow meteoroid = 50m -> .5 kilometers Crater : 1.19 kilometers 1.19 .5 = 2.38 -> 238% bigger You're off by a factor of 10 (B) KE = (270,000,000 x 20^2) / 2 KE= 2.7e10 Check how you typed this into your calculator c) number 2 Because velocity is squared in the equation for KE so changes in velocity have a bigger effect on the kinetic energy than changes in mass.
11.6 The Cassini Division is a gap between Saturn's A and B rings. Mimas' 2:1 resonance governs the Cassini Division's inner edge. Ring particles at this location complete two orbits for every orbit of the moon Mi-mas. Resonance happens when 2 objects have periods that are simple fractions of one another. This produces a periodic alignment of the objects and therefore gravitational tugs that add up over time. Over time the orbit of the ring particle is perturbed which causes collisions with other particles and a change in their orbits. In this way a gap is cleared out in the rings. The diagram in Figure 11.25 shows a 2:1 resonance between Mimas and particles in the inner edge of the Cassini Division. Many other resonances occur between moons and between ring particles and moons in the Sat-urn's system. Another example is the Janus' 4:3 resonance that drives the second-strongest wave in the A ring. Represent in the diagram be-low the 4:3 resonance be-tween a ring particle in the A ring and the moon Janus.
-
5.8 label the parts of the sun
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15.9 Besides single planets, astronomers have discovered many multiple planetary systems. One example is the planetary system orbiting the sun-like star Kepler-11. Six planets have been found in this system. All six planets are larger than Earth, with the largest ones being comparable in size to Uranus and Neptune. How does this planetary system compare to our Solar System? The Figure 15.22 illustrates Kepler's planets (with the radius of the planets in Earth radius and the distance to its star in astronomical units) and the planets in our Solar System. It presents the right order of the planets in the Solar System even though planet sizes and distances are not to scale. Draw arrows to indicate where the planets of the Sun-like star Kepler-11 would be in the Solar System. How does this planetary system compare to our own? What are the prospects for complex life on these planets?
- It is way smaller than our own. The prospects for life are not very good. All of the planets in this solar system are extremely close to their star, meaning that it would be impossible for liquid water to exist. - Kepler's planets are round.
3.8 What are the advantages of a reflector over a refractor telescope?
- Reflector focus all colour at the same point so it won't have chromatic aberration like refractor does. - Reflectors also require a much shorter path length, which allows telescopes to be housed in smaller buildings. - Additionally reflectors are easier to construct and less expensive.
6.7 Kepler's third law can be applied to objects in orbit around the Sun. p2 = a3, where p is the period in years and a is the semi-major axis in AU. Newton derived a more general version of Kepler's third law that can be applied when the body is not orbiting the Sun. p2 = (4pi2/GM)*a3, where M is the total mass in kg, p is the period in seconds, a is the semi-major axis in meters, and G is the gravitational constant = 6.674 x 10-11 m3 kg-1 s-2. NASA's MESSENGER spacecraft entered in orbit around mercury to study the planet. On April 25, 2011 MESSENGER was at a distance of 10,124 km from the center of Mercury and the orbit period was 12 hours and 2 minutes. Estimate the mass of planet Mercury using the more general version of Kepler's third law. Compare your results with the value of Mercury's mass on the Table of Numerical Characteristics of Mercury.
- idk
6.8 Let's make a rough estimate of the size of Mercury's iron core. Mercury's crust and mantle have an average density, pshell, of 3,000 kg/m3 and the iron core has a density, pcore, of 7,800 kg/m3. The volume of a sphere is 4/3*pi*r3 and Mass = density * volume. Mercury's radius is 2,425 km. Use your mass result from question 6.7. a) What is the mass of Mercury's core given in terms of the core radius Rcore? b) What is the mass of Mercury's crust and mantle shell given in terms of the R core? (Remember that a shell's volume can be calculated as the volume of the planet minus the volume of the core). c) Since the mass of the planet is equal to the sum of the core and the mantle and crust shell masses, calculate R core. d) What percent of the planet's radius is the core radius Rcore?
- idk
5.2 The sun's luminosity, energy output, is 3.8x10^26 watts which means 3.8x10^26 Joules of energy released each second. The Hiroshima bomb in Japan released 20,000 tons of TNT, the energy equivalent to 84 TJ; 1 TJ= 1x10^12 Joules). How does the energy radiated by the Sun in one second compare with the release of energy of the atomic bomb dropped in Hiroshima?
1 second worth of the Sun's luminosity = 4.53x10^12 (3.8x10^26/8.4x10^13) Hiroshima nuclear bombs.
3.7 Rank the radiation in order of wavelength size - shortest to longest: gamma rays, infrared, visible, X-rays, radio
1. Gamma Ray (10^-15 to 10^-11 m) 2. X Ray (10^-11 to 10^-9 m) 3. Visible (10^-7 to 10^-6 m) 4. Infrared (10^-6 to 10^-3 m) 5. Radio (10^-1 to 10^5 m) Radiation with a smaller wavelength size is more dangerous because it can penetrate things more deeply and is more energetic. Gamma rays can penetrate your body at the atomic level because they are about the size of atomic nuclei.
1.3. Link the scientist or philosopher to their accomplishments (letters). 1- Eratosthenes _________ 2- Aristotle _____________ 3- Galileo ______________ 4- Tycho Brahe __________ 5- Copernicus ___________ 6- Kepler _______________ 7- Newton ______________ 8- Aristarchus ___________ 9- Ptolemy ______________ A- First to propose that the Earth revolves around the Sun. B- Stated that the planets move in elliptical orbits and the Sun occupies one focus. C- Performed very accurate observations of the positions of the planets and stars. D- Published the heliocentric model. E- Observed with a telescope the phases of Venus, sunspots, craters on the Moon, and the moons of Jupiter. F- Developed a detailed mathematical geocentric model. G- Measured the circumference of Earth. H- Famous philosopher of Antiquity who claimed that the motions of the planets had to be com-binations of circular uniform motions, reflecting the heaven's perfection. I- Explained why planets are kept in orbit. J- Was condemned by the Inquisition for defending the heliocentric model. K- Described the planetary motions with three laws. L- Author of the law of inertia. M- Published the Almagest.
1. g 2. h 3. e & j 4. c 5. d 6. k & b 7. l & i 8. a 9. f & m
10.7 7. The Roche Limit- the distance within which a celestial body, like a comet, held together only by its own gravity, wil disintegrate due to the tidal forces of a larger body - mathematically expressed as Dr = R x (2.44 Pp / Pc) ^ ⅓ Q: Dr =? R = 69,900 km PP = 1.34 g/cm ^3 Pc = 0.5 g/cm^3
A: D = about 131,000 km
3.11 Q: A CA ii line has a laboratory wavelength of 3934.777 A. The spectrum of a star shows this spectrum @ 3935.003 A. What can you conclude about the motion of this star?
A: the star is moving away from earth, which lowers the wave length
13.4 The brightness of sunlight that reaches a planet is inversely proportional to the square of the distance from the planet to the Sun. For example, at a distance of 4 AU from the Sun, sunlight is only 1/(4)2 = 1/16 as bright as at 1 AU. Compared with the brightness of sunlight on Earth, how dim does the Sun look like at Neptune's distance (30 AU from the Sun)?
A:1/(30)2 = 1/900, The Sun looks 900 times dimmer at Neptune's distance
14. 7) Measurements of the brightness of an asteroid were collected at a tele-scope for part of three nights and phased together to create a rotation curve. From the plot in Figure 14.30 estimate the ro-tation period and amplitude of the aster-oid. Remember that rotation period is the time it takes for the object to make a complete sinusoid (wave like curve), and the amplitude is the range of the object in magnitude space.
Amplitude: 0.5 magnitudes Rotational Period : about 5 hours
4.12 How did the iron-nickel cores of the planets form?
As protoplanets and materials melted they went through differentiation so iron and nickel sank to the core.
6.4 Why is Mercury's surface covered in steep cliffs?
As the planet cooled, it shrunk, causing the planet's surface to contract, creating lobate scarps.
13.3 Neptune and Uranus, the ice giants, are similar in: a) size, mass, internal structure, atmospheric activity, and magnetic field properties. b) size, internal structure, mass, rings, and magnetic field properties. c) mass, atmospheric, activity, internal structure, rings, and size. d) internal structure, rings, magnetic field properties, and atmospheric activity.
B
6.1 If Mercury is the closest planet to the Sun, why isn't it the hottest?
Lack of an atmosphere to retain heat, or at least its atmosphere isn't as thick as Venus'
9.9 What evidence indicate that ancient Mars was a much more hospitable place for life?
Mars likely had a thicker atmosphere during its early history and allowed for rivers, lakes, and oceans. In 2004, it has sedimentary rocks, sulfate salts, and hematite, creating a salty shoreline. In addition, there are carbonates, hydrated minerals and sulfates, making liquid form. Most of the water escaped in space and turned into polar caps.
7.4 Why are small craters common on the surface of the Moon but not on Venus?
The atmosphere is so thick only large meteors make it to the surface
7.2 Why does Venus exhibit flake tectonics rather than plate tectonics?
The crust is too thin and flexible so the entire crust is just one huge plate. So it wrinkles and flakes
1.9 figure 1.25 shows Galileo's drawings of planet Venus. Explain why his observations of Venus supported the heliocentric model.
The heliocentric model would go through all the phases of the moon and it would look smaller during crescent and larger during gibbous. In a geocentric model, the moon would always be a crescent.
4.7 Based on what you have learned do you expect terrestrial Earth-like planets to be found in the outer or inner parts of other planetary systems? Explain your answer.
The innermost region because they are closer to the sun, within the snowline and the metals are hot enough to condense and the gases evaporate.
8.35 Why don't we have an eclipse of the Sun every new moon?
The moons orbit is tilted so it doesnt always pass in front of the sun, and isnt always at the right distance
6.3 Why did it come as a surprise that Mercury has a global magnetic field?
The planet's core should have solidified during its formation due to its size, but the global magnetic field proves that its core must still be liquified.
4.10 What is the snow line and where is it located in the Solar System?
The snow line is the boundary where water would be cold enough to freeze. This line is located 5 AU from the sun between the terestrial and gas planets.
5.4 What makes the fusion reactions in the Sun a controlled process? Why doesn't the Sun explode as a gigantic H-bomb? Describe the Sun's thermostat.
The sun doesn't explode because the pressure of its gravity keeps the sun's matter under control. If the sun heats up too much, it expands, cools, and returns to normal size.
5.7 Because of the solar wind, the Sun is slowly losing mass. The Sun loses about 107 tons per second. a. How much mass does the Sun lose through the solar wind in a year? b. How much mass has the Sun lost in a person's lifetime? (Use a typical lifetime of 70 years.) what percent of the Sun's mass does this represent. c. How much mass does the Sun lose in a billion years (suppose the solar wind does not vary with time)? What percent of the Sun's mass does this represent.
a. The sun will lose 3.37435x10^7 tons of mass per year. b. The sun will lose 2,362,045,000 tons in 70 years. This represents 1.1810225x10^-19% of the mass of the sun, or essentially 0%. c. (losses 3.374x10^7 tons per year, one billion = 1,000,000,000 = 1x10^9) 3.374x10^16 tons; (3.374x10^16/1.99x10^30 x 100) 1.695x10^-12%
8.30 Fill in the blanks with the correct lunar phase. a. A lunar eclipse can only occur during a b. A solar eclipse can only occur during a
a. full moon b. new moon
14.2 Vesta, the second largest asteroid in the Asteroid Belt, was visited by the NASA spacecraft Dawn in July 2011. It has a di-ameter of 530 km (329 mi), about half of Ceres' diameter which is the largest aster-oid in the Asteroid Belt and now considered a dwarf planet. a) In Figure 14.26, near the image center there is a deep cliff. Using the image's scale on the bottom right, measure the mean depth of the cliff from top to bottom. (Tip: First measure in millimeters the straight line that corresponds to 20 km. 2 Divide 20 by this number to get the scale in km/mm. Then measure the depth of the 1 cliff in mm and multiply by the scale to get the result in km.) b) Using the image scale, estimate the diameter of craters 1 and 2.
a.) =20 km 1=36km 2=10km It wants the average value, and please explain what you did in a few sentences so others can follow
11.1The only bodies in the Solar System to have liquid lakes on their surface are: a. The Moon and Earth b. The Earth, Mars, and Titan c. Europa, Titan, and Earth d. Earth and Titan e. Mars, Earth, and Titan
b
12.3 An observer on Uranus' equator would see the sun overhead during: a. The summer b. The spring and fall c. The winter and summer d. The winter e. None of the above
b
3.1 The diameter of a telescope's mirror or lens is called: a. The light gathering power b. Aperture c. The magnification d. The focal length
b
3.2 .The primary mirror of a telescope is called: a. The focal length b. Objective c. The light gathering power d. Eyepiece
b
3.3 The antenna of a radio telescope detects: a. Sound waves. b. Radio waves. c. Infrared waves. d. Both a) and b). e. none of the above.
b
8.29 Why do tides occur? a. Moon moves closer and farther from earth in orbit b. Different parts of earth experience different gravitational pull c. Sun moon earth alignment d. Ocean has different rotation rate None
b
1. 7 Table 1.1 lists the average distance from the planet to the Sun (the semi-major axis). a) Use Kepler's third law P2 = a3 to fill out the table. b) As the size of the orbit increases, what happens to the period? c) Earth's orbit around the Sun has a very low eccentricity (e=0.0167), therefore it is nearly a circle. What would happen to the length of the year if the eccentricity was much higher
b. The period increases c. The Length of Year would stay the same, but the orbit would become more oval shapped.
4.3. Why are there compositionally different types of planets? a) Because some had initially more gravity and hence grew much faster. b) Because the Sun dispersed the material in the inner disk and only small planets could form. c) Because the solar nebula had different composition at different regions. d) Because the Sun's gravity attracted metals and rock to the inner regions. e) Because the kinds of material that condensed depended on the temperature of the disk.
e
8.26 If the moon is full when rising in the east, which phase will it be when setting in the west? a. Gibbous waning b. Gibbous waxing c. Crescent waning d. Third quarter e. Full f. None
e
11.5 Spectrographs allow astronomers to obtain the spectra (light separated into different wavelengths) of different astronomical ob-jects. One important piece of information that can be extracted from a spectrum is the speed at which an object is either approach-ing or receding from us. If an object is approaching the observer, then the wavelengths of the expected spectral lines will be shifted toward the blue, whereas a receding object will have its spectral lines shifted toward the red. As astronomers observe the spectra of different parts of the Saturnian rings, which of the options is true? a. the observer will see spectra A and B shifted toward the red while spectrum C will be shifted toward the blue. b. The observer will see spectra A and B shifted toward the blue while spectrum C will be shifted toward the red. c. The observer will see all spectra shifted toward the blue. d. The observer will see spectrum A shifted toward the blue while spectrum C will be shifted toward the red and spectrum B will have no shift. e. The observer will see spectrum A shifted toward the red while spectrum C will be shifted toward the blue and spectrum B will have no shift.
e.
1.2 Ancient Greeks long suspected that Earth was spherical because a) a sphere was considered the most perfect geometrical form. b) they did not detect any parallax. c) during lunar eclipses Earth's shadow cast on the Moon was always round. d) the ships disappeared on the horizon likely due to Earth's curvature. e) a and c. f) c and d.
f
