Details Title: Astronomy 10 - Elementary Astronomy Description: Midterm Study Cards Fall 2009 Total Flash Cards: 70 Created: 10/10/2009 01:55:02		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Astronomy Flashcards
Cards in this set: Term Which of the following has your “address in the correct order? Definition You, Earth, Local Group, Local Supercluster, solar system, Milky Way   Term Which of the following statements about the celestial sphere is not true? Definition The “celestial sphere” is just another name for our universe.   Term Which of the following statements about the celestial equator is true at all latitudes?   Definition It represents an extension of Earth's equator onto the celestial sphere.   Term What is the ecliptic?   Definition The Sun's apparent path along the celestial sphere.   Term Which scientists played a major role in overturning the ancient idea of an Earth-centered universe and about when?   Definition Copernicus, Kepler, and Galileo; about 400 years ago.   Term Which of the following correctly describes the meridian in your sky?   Definition A half-circle extending from your horizon due north, through your zenith. To your horizon due south. Term How many archminutes are in 1 degree?   Definition 3,600   Term What is a circumpolar star? Definition A star that always remains about your horizon. Term Which of the following is not a phase of the Moon? Definition Half Moon Term If the moon is setting at 6AM, the phase of the Moon must be: Definition Full   Term What is an astronomical unit? Definition The average distance from the Earth to the Sun.   Term How did Eratosthenes estimate the size of Earth in 240BC? Definition By comparing the maximum altitude of the Sun in two cities at different latitudes. Term Where was the Sun in Ptolemy's model of the universe? Definition Between the orbits of Venus and Mars Term The controversial book of this famous person, published in 1543 (the year of his death), suggested that Earth and the other planets orbit the Sun.   Definition Copernicus   Term He discovered that the orbits of planet are ellipses.   Definition Kepler   Term He discovered that Jupiter has moons. Definition Galileo Term If your mass is 60kg on Earth, what would your mass be on the Moon?   Definition 60kg Term What would happen if the Space Shuttle were launched with a speed greater than Earth's escape velocity?   Definition It would travel away from Earth into the solar system. Term The force of gravity is an inverse square law. This means that, if you double the distance between two large masses, the gravitational force between them will: Definition Weaken by a factor of 4. Term According to the universal law of gravitation, if you double the masses of both attracting objects, then the gravitational force between them will: Definition Increase by a factor of 4. Term An atom in a excited state contains more of what type of energy than the same atom in the ground state? Definition Electric potential energy.     Term The wavelength of a wave is:   Definition The distance between two adjacent peaks of the wave. Term How are wavelength, frequency, and energy related for photons of light? Definition Longer wavelength means lower frequency and lower energy. Term From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation? Definition Radio, infrared, visible light, ultraviolet, X rays, gamma rays Term When an electron in an atom goes from a higher energy state to a lower energy state, the atom: Definition Emits a photon of a specific frequency. Term The spectra of most galaxies show redshifts. This means that their spectral lines: Definition Have wavelengths that are longer than normal. Term From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude? Definition The star is moving away from us.     Term How does the Sun's mass compare with that of the planets? Definition It's a 1000 times more massive than all the planets combined. Term Which planet has the highest average surface temperature, and why? Definition Venus, because of its dense carbon dioxide atmosphere. Term Which planet, other than Earth, has visible water ice on it? Definition Mars Term Which of the following is furthest from the Sun? Definition A comet in the Oort cloud. Term Which is the densest planet in the solar system? Definition Earth Term The planet closest in size to Earth is: Definition Venus Term Which of the following is not a characteristic of the inner planets?   Definition They all have substantial atmospheres. Term Which of the following is not a characteristic of the outer planets? Definition They have very few, if any, satellites. Term Why did the solar nebula heat up as it collapsed? Definition As the cloud shrank, its gravitational potential energy was converted to kinetic energy and then into thermal energy. Term What kind of material in the solar nebula could remain solid at temperatures as high as 1500K, such as existed in the inner regions of the nebula? Definition Metals.   Term What was the frost line of the solar system?   Definition The distance from the Sun where temperatures were low enough for hydrogen compounds to condense into ices, between the present-day orbits of Mars and Jupiter.   Term According to the nebular theory, what are asteroids and comets?   Definition The are leftover planetesimal's that never accreted into planets. Term Rank the five terrestrial worlds in order of size from smallest to largest:   Definition Moon, Mercury, Mars, Venus, Earth Term Which of the terrestrial worlds has the strongest magnetic field? Definition Earth Term Which of the following most likely explains why Venus does not have a strong magnetic field?   Definition Its rotation is too slow.   Term Which two properties are most important in determining the surface temperature of a planet?   Definition Distance from the Sun and atmosphere. Term How large is an impact crater compared to the size of the impactor? Definition 10 times larger. Term The relatively few craters that we see within the lunar maria: Definition Were formed by impacts that occurred after those that formed most of the craters in the lunar highlands. Term The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From the we conclude that: Definition The Caloris Basin formed toward the end of the solar system's period of heavy bombardment. Term Olympus Mons is a: Definition Shield volcano on Mars Term Why does Venus have such a great difference in temperature between its “no atmosphere” temperature and its actual temperature? Definition It has a large amount of greenhouse gases in its atmosphere. Term Which of the following worlds has the most substantial atmosphere?   Definition Venus Term Why doesn't Venus have seasons like Mars and Earth do? Definition Its rotation axis is not tilted. Term Where is most of the water on Mars? Definition Frozen on the peaks of its tall volcanoes. Term How does Jupiter's core compare to Earth's? Definition It is about the same size but is 10 times more massive.   Term If we know the size of an asteroid, we can determine its density by: Definition Determining its mass from its gravitational pull on a spacecraft, satellite, or planet.   Term What is Jupiter's Great Red Spot? Definition A long-lived, high pressure storm. Term The four Galilean moons around Jupiter are: Definition A mixture of rock and ice, with the ice fraction increasing with distance from Jupiter. Term Why are there no impact craters on the surface of Io? Definition Io did have impact craters but they have all be buried in lava flows. Term Which moon has the most substantial atmosphere? Definition Titan Term How thick are Saturn's rings from top to bottom?   Definition A few tens of meters.   Term Which is closest tot he average distance between asteroids in the asteroid belt? Definition 1 million km Term Why isn't there a planet where the asteroid belt is located?   Definition   Gravitational tugs from Jupiter prevented materials from collecting together to form a planet.   Term What do we call a small piece of solar system debris found on Earth? Definition Meteorite   Term Halley's comet is named after the English scientist Edmund Halley because he: Definition Calculated its orbit and predicted that it would return in 1758. Term What part of a comet points directly away from the Sun? Definition The plasma tail   Term Most of the planets discovered around other stars: Definition Are more massive than Earth and orbit very close to the star. Term The core of the Sun is: Definition Hotter and denser than the surface.   Term What two forces are balanced in what we call gravitational equilibrium?   Definition Outward pressure and gravity. Term What is the average temperature of the surface of the Sun?   Definition 6,000K   Term Which layer of the Sun do we normally see? Definition Photosphere   Term At the center of the Sun, fusion converts hydrogen into: Definition Helium, energy, and neutrinos.   Term What is granulation in the Sun? Definition The bubbling pattern on the photosphere produced by the underlying convection.