ASTR 1504 1514 Astronomy Exploring the Universe Midterm Exam 2 1 Which of the following contributes most to the large difference in the average daytime and nighttime temperatures on the Moon A The lack of a hydrosphere B The lack of a magnetosphere C The lack of an atmosphere D The lack of geologic activity 2 Why did the terrestrial planets lose their primary atmospheres A Their low gravities couldn t hold them B The solar wind blew them away C Their high surface temperatures made them chemically react with rock D The centrifugal force from their fast rotation rates made them fly off 3 Venuss surface temperature is fairly uniform from the equator to the poles because A Venus rotates very rapidly which causes strong zonal winds B Venus is covered by a thick cloud layer that absorbs most of the sunlight that falls on it C the carbon dioxide in Venuss atmosphere efficiently emits infrared radiation D Venus rotates slowly so Coriolis forces do not disrupt Hadley circulation 4 Which component in our atmosphere is a direct consequence of the emergence of life A Carbon dioxide B Water vapor C Nitrogen D Oxygen 5 The gas giants are composed primarily of A hydrogen B helium C water D ammonia 6 The compositions of Uranus and Neptune differ primarily from that of Jupiter and Saturn in that the outer two planets contain more A hydrogen B helium C water ice D carbon dioxide 7 Why are Jupiter and Saturn not perfectly spherical A They formed from the collision of two large planetesimals B They rotate rapidly C They have storms that develop preferentially along their equators D They have very active aurorae that heat the atmospheres along the poles 8 As a group which is the following describes the rotation of giant planets compared to terrestrial planets A faster than B slower than C the same as D retrograde compared to 9 What is the most common geologic feature seen on moons A Craters B Volcanoes C Palimpsests D Geysers 10 Which property of a moon might lead you to believe it was a captured asteroid A It is tidally locked B Its orbital axis is tilted by 10 degrees compared to the planets rotational axis C It rotates clockwise around the planet when viewed from the planets north pole D Its surface is very smooth and lacks craters 11 Meteorites are more likely to come from asteroids than comets A True B False 12 All meteorites are remnants of planetesimals that never coalesced to form a planet A True B False 13 A parsec is a unit of time A True B False 14 The absolute magnitude of a star is a measure of its luminosity A True B False 15 Stars with a higher apparent brightness are necessarily closer to us than fainter stars A True B False 16 How many arcseconds are there in a degree A 60 B 360 C 3 600 D 6 000 17 When an electron moves from a higher energy level in an atom to a lower energy level A the atom is ionized B a continuous spectrum is emitted C a photon is emitted D a photon is absorbed 18 Star A is a red star Star B is a blue star Which is hotter A Star A B Star B C We also need to know the luminosities of the stars to determine their temperatures D Color is not related to temperature at all 19 The spectral class of a star is related to its A luminosity B temperature C radius 20 Stars are made mostly of A helium B oxygen C hydrogen D nitrogen 21 In the quantum mechanical view of the atom an electron is best thought of as A a cloud that is centered on the nucleus B a pointlike particle orbiting the nucleus C free to orbit at any distance from the nucleus D all of the above are true 22 Binary star systems are extremely useful in studying stars because they allow us to determine stars masses A True B False 23 Which sequence correctly lists the spectral classes of stars in order of decreasing temperature from hottest to coolest A A B F G K M O B O A B G F M K C A F O B M G K D O B A F G K M 24 When looking at a standard H R diagram the hottest stars are on the left hand side of the diagram A True B False 25 Main sequence stars range in mass from approximately A 0 5 to 10 M B 0 08 to 140 M C 1 to 100 M 26 In our Sun hydrostatic equilibrium exists only in the core where energy production via fusion can balance gravity A True B False 27 In the proton proton chain the net result is that 4 protons are converted into 1 helium nucleus and energy positrons and neutrinos are released A True B False 28 In the radiative zone inside the Sun photons are transported from the core to the convective zone in a matter of seconds A True B False 29 Our Sun is unique compared to the other stars in our galaxy because of its A temperature B size C evolutionary stage D proximity 30 The majority of the Suns energy comes from A gravitational contraction B its rapid rotation C hydrogen fusion D helium burning 31 Neutrinos are particles with small masses that interact easily with normal matter A True B False 32 The solar neutrino problem was solved by postulating that neutrinos have a small mass and oscillate between three different types of neutrino A True B False 33 The temperature of the corona is much hotter than any other layer in the solar atmosphere A True B False 34 Which of the following methods is least important to transport energy from the core to the surface of the Sun A Radiation B Convection C Conduction 35 Sunspots appear dark because A they have lower densities B they have lower rotation rates C they have lower temperatures D they are storm systems like those on the Jovian planets