Extra credit

Harold Washington College, Chicago

Astronomy 201: Descriptive Astronomy

Exam 2- EXTRA CREDIT Spring 2019

Version D ______________________________________________________________________________________________________

Instructions

The exam consists of 60 Multiple-choice questions including 5 Bonus questions.

Read the question and all the answers carefully before choose your answer.

Choose the best answer and mark your answers with a number 2 pencil on a 5-answer scan sheet (only one answer per question).

Try all the questions and make your best effort. Good luck! ___________________________________________________________________________________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Which planet has the lowest density in our solar system? A) Jupiter B) Saturn C) Uranus D) Neptune E) Mars

2) Rather than being a planet, Pluto is now considered to be a large member of A) an extrasolar planetary system. B) the Kuiper belt. C) the moon system around Neptune. D) the Oort cloud. E) the asteroid belt.

3) Which of the following is most distant from the Sun? A) a comet in the Oort cloud B) Pluto C) a comet in the Kuiper belt D) Eris E) Neptune

4) Which planet hosts the Galilean moons? A) Mars B) Venus C) Jupiter D) Saturn E) Neptune

Descriptive Astronomy 201 Spring 2019

5) The core of the Sun is A) at the same temperature but much denser than its surface. B) constantly rising to the surface through convection. C) at the same temperature and density as its surface. D) composed of iron. E) much hotter and much denser than its surface.

6) The wavelength of one of the absorption lines of hydrogen gas observed in a laboratory is 656 nm. You observe several stars and measure the wavelength of this same hydrogen absorption line in each star. Based on the measured wavelength of this line, which star is moving towards the Earth the fastest?

A) 630 nm B) 640 nm C) 656 nm D) 670 nm E) 635 nm

7) What causes Jupiter and Saturn to have metallic hydrogen in their interiors? A) high pressure B) low pressure C) presence of heavy metals D) high density E) high temperature

8) Why does Mars have more extreme seasons than Earth? A) because it has a more elliptical orbit B) because it has a much larger axis tilt C) because it is farther from the Sun D) because it has more carbon dioxide in its atmosphere E) all of the above

9) A photon with a longer wavelength has A) higher frequency and higher energy. B) higher frequency and lower energy. C) lower frequency and higher energy. D) lower frequency and lower energy. E) There is no simple relationship because different photons travel at different speeds.

10) What is the main composition of Uranus and Neptune? A) mostly rocky B) mostly hydrogen compounds C) mostly nitrogen D) mostly water E) mostly hydrogen and helium

11) What is the origin of the large moons orbiting in the equatorial planes of the jovian planets? A) They were formed by giant impacts. B) They are captured planets. C) They are captured asteroids. D) They are captured comets. E) They were formed by condensation and accretion in a disk of gas around the jovian planet.

2

12) The continuous spectra for four stars is shown here. Which star has the highest temperature?

A) star C (yellow line) B) star A (green line) C) star B (orange line) D) star D (purple line)

Use the diagram below to answer Question 13-14. Hydrogen absorption spectral lines of 3 galaxies D, E and G are compared with observed hydrogen spectral lines (F) under laboratory condition.

13) Which galaxy is moving away from the observer? A) none of them B) Both E and G C) Galaxy G only D) Both D and E E) Galaxy E only

14) Which galaxy is moving faster? A) Galaxy E B) Can not determine with this information C) All of them move at the same speed D) Galaxy G E) Galaxy F

3

15) Where does nuclear fusion occur in the Sun? A) anywhere below the surface B) in the corona C) on the surface (photosphere) D) in its core E) all of the above

16) Which of the following is not a characteristic of the inner planets? A) They have solid, rocky surfaces. B) They are smaller than the outer planets. C) They have relatively high densities. D) Their orbits are relatively closely spaced. E) They have substantial atmospheres.

17) What is the Great Red Spot? A) a huge impact by shoemaker levy comet on Jupiter's surface B) a high-pressure storm on Jupiter C) a place where reddish particles from Io impact Jupiter's surface D) a region on Jupiter where the temperature is so high that the gas glows with red visible light E) a hurricane on Uranus

18) Which of the following lists the planets of our solar system in the correct order from closest to farthest from the Sun?

A) Mercury, Venus, Mars, Earth, Saturn, Jupiter, Neptune, Uranus B) Earth, Mars, Mercury, Venus, Jupiter, Saturn, Uranus, Neptune C) Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune D) Mercury, Earth, Venus, Mars, Jupiter, Saturn, Neptune, Uranus

19) Before New Horizons fly by Pluto, scientists had thought Pluto would be geologically dead, but New Horizons mission showed it has

A) a heavily cratered surface due to giant impacts. B) active volcanoes C) a very old surface, indicating no geological activity. D) a surface of rock. E) smooth plains most notably a heart shape plain resulting from recent geological activity.

20) According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size?

A) Its mass, temperature, and density all increased. B) It got hotter, its rate of rotation increased, and it flattened into a disk. C) It gained energy, it gained angular momentum, and it flattened into a disk. D) Its gas clumped up to form the terrestrial planets, nuclear fusion produced heavy elements to make the

jovian planets, and central temperatures rose to more than a trillion Kelvin.

4

21) What do sunspots, solar prominences, and solar flares all have in common? A) They all have about the same temperature. B) They are all shaped by the solar wind. C) They all occur only in the Sun's photosphere. D) They are all strongly influenced by magnetic fields on the Sun.

22) The Chandra X-ray Observatory must operate in space because A) X-rays do not penetrate Earth's atmosphere. B) X-rays are too dangerous to be allowed on the ground telescopes. C) X-ray telescopes require the use of grazing incidence mirrors. D) NASA didn't like to operate it on ground.

23) What mechanism is most responsible for generating the internal heat of Io that drives its volcanic activity? A) accretion B) bombardment C) radioactive decay D) differentiation E) tidal heating

24) Which of the following is not true of Mercury? A) Mercury is the densest planet in the solar system. B) It has the most extreme temperature difference between day and night due to its slow rotation C) It has long, tall cliffs. D) It has no moons. E) Its surface is heavily cratered.

25) Where are most of the known asteroids found? A) in the Oort cloud B) in the Kuiper belt C) between the orbits of Jupiter and Saturn D) between the orbits of Earth and Mars E) between the orbits of Mars and Jupiter

26) By what process does the Sun generate energy? A) nuclear fission B) gradual expansion C) nuclear fusion D) gravitational contraction E) chemical reactions

27) If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas with this same emission line at 680.2 nm?

A) It is neither receding nor approaching us. B) It is approaching us. C) It is receding away from us. D) The location of the emission line has nothing to do with speed.

5

28) Considering only the tilt of their axis, which planet listed below would have the most extreme seasons? A) Mercury B) Neptune C) Jupiter D) Mars E) Uranus

29) In what ways is Earth different from the other terrestrial planets? A) Most of its surface is covered with liquid water. B) Life can be found almost everywhere on its surface. C) It has a much higher percentage of oxygen in its atmosphere. D) It is still geologically active. E) All of the above are true.

30) What atmospheric constituent is responsible for the blue color of Uranus and Neptune? A) water B) carbon dioxide C) ammonia D) methane E) hydrogen

31) Rank the five terrestrial worlds in order of size from smallest to largest. A) Moon, Mercury, Mars, Venus, Earth B) Mercury, Moon, Mars, Earth, Venus C) Moon, Mercury, Venus, Earth, Mars D) Mercury, Venus, Earth, Moon, Mars E) Mercury, Moon, Venus, Earth, Mars

32) A rocky leftover planetesimal orbiting the Sun is A) a comet. B) a meteor. C) a meteorite. D) an asteroid. E) an interstellar object

33) Which of the following does not have a major effect in shaping planetary surfaces? A) impact cratering B) erosion C) magnetism D) volcanism E) tectonics

34) Which of the following best describes the lunar maria? A) relatively smooth, flat plains on the Moon B) region covered by powdery soil on the Moon C) densely cratered regions on the Moon D) mountainous regions on the Moon E) frozen oceans of liquid water on the Moon

6

35) Rocks that enter the Earth's atmosphere and blaze a trail all the way to the ground, do not burn up completely and left fragments on ground are known as

A) meteorites B) meteors C) comets D) asteroids E) impacts

36) What is the overall composition of the Sun? A) Unknown yet. B) nearly equal portions of all the elements such as hydrogen, helium, carbon, oxygen C) 99% hydrogen & helium and 1% everything else D) 100% hydrogen. Nothing else E) 50 % hydrogen & helium and 50% everything else

37) Consider an atom of iron in which the nucleus contains 26 protons and 30 neutrons. What is its atomic number and atomic mass number?

A) The atomic number is 30, and the atomic mass number is 26. B) The atomic number is 26, and the atomic mass number is 56. C) The atomic number is 30, and the atomic mass number is 56. D) The atomic number is 26, and the atomic mass number is 30.

38) Planetary rings A) orbit in the equatorial plane of their planet. B) are composed of countless ice particles that orbit their planet. C) exist around all of the jovian planets. D) all of the above

39) Which of the following is NOT a characteristic of the jovian planets? A) They have rings. B) They have thick atmospheres. C) They are primarily made of hydrogen, helium, and hydrogen compounds. D) They have higher density than terrestrial planets. E) Their orbits are separated by relatively large distances.

40) Which planet has the highest average surface temperature, and why? A) Mercury, because it is closest to the Sun B) Venus, because of its dense carbon dioxide atmosphere C) Jupiter, because it is so big D) Earth, because of its greenhouse effect E) Mars, because of its red color

41) Which type of electromagnetic radiation has the highest Energy? A) infrared B) X-rays C) Gamma rays D) ultraviolet E) radio waves

7

42) In essence, the solar nebular theory states that ________. A) the planets each formed from the collapse of its own separate nebula B) our solar system formed from the collapse of an interstellar cloud of gas and dust C) nebulae are clouds of gas and dust in space D) The nebular theory is a discarded idea that imagined planets forming as a result of a near-collision

between our Sun and another star.

43) Why do asteroids and comets differ in composition? A) Asteroids and comets formed at different times. B) Comets formed from the jovian nebula, while asteroids did not. C) Asteroids formed inside the frost line, while comets formed outside. D) Comets are much larger than asteroids. E) Asteroids formed outside the frost line, while comets formed inside.

44) Which direction does a comet's plasma tail point? A) perpendicular to the ecliptic plane B) toward the Sun C) straight away from the Sun D) straight behind the comet in its orbit E) always almost due north

45) Which moon has the thickest atmosphere, which is made mostly of nitrogen? A) Titan B) Europa C) Triton D) Ganymede

46) Why does Jovian planets have different layers of clouds? A) Different gases are present at different altitudes in Jupiter's atmosphere. B) Winds prevent clouds from forming at some altitudes, so we see clouds only at the other altitudes. C) Clouds form randomly, so on average there are always several layers. D) Layers of clouds are made up of different gases that condense at different temperatures.

47) Which of the following statement is true about following spectrums?

Spectrum A

Spectrum B

A) Spectrum A is an emission spectrum and Spectrum B is an emission spectrum B) Spectrum A is an absorption spectrum and Spectrum B is an emission spectrum C) Spectrum A is an emission spectrum and Spectrum B is an absorption spectrum D) Spectrum A is an absorption spectrum and Spectrum B is a continuous spectrum

8

48) Which planet has the most extreme temperature difference between day and night? A) Earth B) Venus C) Mars D) Mercury E) Jupiter

49) What is Pluto's moon Charon thought to have in common with our own Moon? A) It has the same basic composition. B) It probably formed as a result of a giant impact. C) It has the same approximate mass. D) It has the same average density.

50) Which of the following types of material were condensed into what we call ice beyond the frost line during the formation of planets in the solar nebular?

A) carbon B) hydrogen compounds C) hydrogen and helium D) rocks E) metals

51) What observational evidence supports the idea that Mercury shrank after it formed? A) the presence of smooth surfaces B) the presence of many impact craters C) the presence of many long, tall cliffs D) the characteristics of the Caloris Basin

52) Which of the following correctly orders the different categories of electromagnetic radiation from shortest to longest wavelength?

A) infrared, visible light, ultraviolet, X-rays, gamma rays, radio B) radio, infrared, visible light, ultraviolet, X-rays, gamma rays C) gamma rays, X-rays, ultraviolet, visible light, infrared, radio D) ultraviolet, X-rays, gamma rays, visible light, infrared, radio E) X-rays, gamma rays, ultraviolet, visible light, infrared, radio

53) The average surface temperature of the Sun is about ________. A) 5,800 K B) 1,000 K C) 40,000 K D) 1 million K

54) Why does a sunspot appear dark? A) A dark sunspot is composed of different elements than the rest of the Sun. B) A dark sunspot is significantly cooler than the surrounding area on the Sun's surface. C) The spots are openings which the sun's interior layers can be seen. So it's dark in there! D) They are regions that do not emit any radiation. So they are dark!

55) What is the most volcanically active body in our solar system? A) Io B) Titan C) Triton D) Ganymede E) Europa

56-60 are Bonus questions. Recommend to attempt all Bonus question!

56) Ceres is located in the astroid belt and it is the largest asteroid, but it gets classified as a dwarf planet, Why? A) It's composition is similar to Pluto. B) It is large enough to be spherical in shape but not large enough to clear its orbit. C) It is larger than Pluto. D) It orbits inside the frost line.

9

57) All of the planets rotate on their axis in the same direction, except Venus and Uranus. According to our theory of solar system formation, how do we explain these exceptions to the general patterns of the planets?

A) Venus and Uranus are also rotates in the same directions. No worries! B) Unusual rotations of these planets are the result of giant impacts. C) We can't explain these exceptions with our theory. D) These planets were gravitationally captured by the Sun.

58) The graph below illustrate fraction of sunspots covered on Sun's surface. A minimum is shown in 2008. When would you expect the NEXT sunspot minimum to occur?

A) 2025-2026 B) 2014 -2015 C) 2019-2020 D) 2119-2120

59) Which statement is NOT true of all comets in our solar system? A) All comets are leftover planetesimals that originally condensed beyond the frost line in the solar nebula. B) Comets always have dust and plasma tails. C) All comets orbit the Sun. D) All comets are icy in composition.

60) Which of the following is the main reason why Venus has so little wind erosion on its surface? A) its orbital path B) its relatively close distance from the Sun C) its thick atmosphere D) its small size E) its slow rotation

10