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As astronomers have learned r. re about the structure of the Sun, they have found that it
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The most common element in the Sun is
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genreal astronomy
midtern
| Question | Answer |
|---|---|
| As astronomers have learned r. re about the structure of the Sun, they have found that it | is made entirely of hot gas |
| The most common element in the Sun is | Hydrogen |
| As you go upwards from the Sun's photosphere, | the density (number of atoms in a unit volume) decreases |
| Solar wind particles can be captured by the Earth's magnetosphere. When these particles spiral down along the magneti into the atmosphere, they are responsible for: | aurorae (northern and southern lights) |
| The granulation pattern that astronomers have observed on the surface of the Sun tells us that: | hot material must be rising from the Sun's hotter interior |
| Sunspots are darker than the regions of the Sun around them because | they are cooler than the material around them (although still very hot compared to Earth temperatures) |
| Which statement about the Sun's rotation is TRUE? | The Sun rotates at different rates at different latitudes on |
| The material inside the Sun is in the form of a | plasma |
| Which part of the Sun has the greatest density? | the core |
| Astronomers and physicists now believe they know what is happening to the missing neutrinos from the Sun These neutrinos are: | turning into a different type of neutrino |
| The way scientists know that a hypothesis in astronomy is a reasonable description of nature is to | do experiments and observations about the predictions of the hypothesis |
| A light year is | the distance that light travels in one year |
| A star is 230 light years away. The light we see tonight from that star left it | 230 years ago |
| The location of the Earth in the Milky Way Galaxy is | a little less than 30,000 light-year from the center. |
| Even with the best and largest telescopes, we can't see all the stars in the Milky Way Galaxy, even though these same telescopes can show us other galaxies. Why is that? | Dust in the space between stars builds up over large distances and blocks the light of stars behind the dustier parts of the Milky Way. |
| By the term universe, astronomers mean | everything that we can observe. |
| Light travels 3 x 105 meters every second. That number in words is | 300,000 kilometers |
| The Astronomical Unit (AU) as defined by astronomers is | the average distance between the Earth and the Sun. |
| A large body in space that consistently makes its own light (instead of merely reflecting another body's light) is called | a star |
| For scientists, an element (like gold) is defined by | the number of protons in its nucleus. |
| The point in the sky directly above your head at any given time is called the | Zenith |
| The celestial sphere turns once around each day because | the planet on which we live is rotating |
| In the Northern Hemisphere, the altitude (height in degrees above the horizon) of the North Star is always roughly equal to the | latitude of the observer |
| The Sun's apparent path around the celestial sphere is called | the ecliptic |
| The 88 sectors into which astronomers today divide the celestial sphere (the whole sky) are called: | Constellations |
| How did Eratosthenes measure the size of the Earth? | |
| When a planet temporarily moves westward in the sky over the course of several weeks or months (instead of eastward, as it typically does), we call it; | Retrograde motion |
| The slow tipping of the Earth's axis in a circle with a period of about 26,000 years is called: | precession |
| According to the geocentric view, everything in the heavens had to go around the Earth, which was the center of the universe. What objects did Galileo discover with his telescope that clearly didn't go around the Earth? | moons around the planet Jupiter |
| In an ellipse, the ratio of the distance between the foci and the length of the major axis is called: | the semi-major axis |
| When a planet, in its orbit, is closer to the Sun, it: | moves faster than average |
| The idea that objects (in the absence of an outside force) tend to continue doing what they are already doing is called the law of | inertia |
| Newton showed that to change the direction in which an object is moving, one needs to apply: | there must be a cause—which is a net external force |
| A single star in the process of forming starts by spinning slowly (while it is quite large and relatively cool.) As the star collapses under the pull of its own gravity, its size decreases. As a result, its rate of spinning: | will increase |
| Newton's reformulation of Kepler's third law allows us to measure the masses of bodies in orbit around each other, if we can measure: | the distances and periods of revolution |
| When a comet like Comet Hale-Bopp comes closest to the Sun in its orbit, we say that it is at: | perihelion |
| The planet in our solar system with the shortest period of revolution is: | Mercury |
| The asteroid belt is | a zone where rocky chunks orbit between Mars and Jupiter |
| The number of degrees of arc that your location is north or south of the Earth's equator is called your: | latitude |
| In locating objects on the Earth, we call the number of degrees east or west that something is from Greenwich, England its: | longitude |
| A star is 230 light years away. The light we see tonight from that star left it | 230 years ago |
| The location of the Earth in the Milky Way Galaxy is | a little less than 30,000 LY from the center |
| If you want to locate someone precisely on the surface of the Earth, you specify her exact latitude and longitude. If you want to locate a star precisely on the sky, you need to specify its exact: | right ascension and declination |
| The Earth is closest to the Sun in which month of the year? | January |
| The time it takes for the Sun to return to the same place in our sky after the Earth has rotated once is called: | a solar day |
| Why is there a 4-minute difference between the solar day and the sidereal day? | because the Earth is going around the sun in the course of a year |
| The terms "a.m." and "p.m." (as in see you at the movies at 8:30 p.m.) derive from what astronomical idea? | the Sun passes through the meridian in roughly the middle of the day |
| The period of the moon's rotation on its axis is | the same as its revolution around the Earth |
| When the Sun and Moon are lined up and pull together, the tides they raise are called: | spring tides |
| the 19th century, it became clear that magnetism was not a separate force, but was always produced by the action of | electric charges that were in motion |
| The light which allows you to see this very interesting quiz is made up of waves. In these waves, the distance between crests is called the: | wavelength |
| How fast do electro-magnetic waves travel? | at the speed of light |
| Which of the following has the highest frequency? | gamma rays |
| (In the absence of a strong magnetic field), what is the chief factor that determines what type of electromagnetic radiation objects give off: | their temperature |
| The Stefan-Boltzmann Law relates the energy flux coming from a blackbody (such as a star) to its: | temperature |
| Why is an absorption spectrum especially useful for astronomers? | It has dark lines in it that allow astronomers to determine what chements are in the star |
| In 1911 Ernest Rutherford did a famous experiment using fast-moving alpha particles as bullets and very thin gold foil as a target. The results of this experiment showed that | that the nucleus of an atom was tiny compared to the size of the whole atom |
| What happens as an electron falls from a higher level to a lower level in an atom? | a photon is given off |
| The ground state in an atom is | the state an electron is in when it has absorbed three or more different photons |
| The most important function of an astronomical telescope is to: | collect as much light as possible and bring it to a focus |
| When a knowledgeable amateur astronomer tells you that she has a 14-inch telescope, what does the number 14 refer to? | the diameter of the primary lens or mirror |
| A new technique called adaptive optics allows astronomers to: | compensate for changes in the Earth's atmosphere and achieve better resolution |
| Why do telescopes have to have a good motorized drive system to move them quickly and smoothly? | because the Earth is rotating, with the telescope attached to it |
| Which of the following has a longer integration time (can collect light for a longer period of time) than the human eye? | photographic film, photographic plates, a CCD (charge coupled device) |
| Which of the following is NOT a detector of radiation from space that astronomers have used? | a refracting telescope |
| To break up light into the component colors that it contains, astronomers use a device called: | a spectrometer |
| Radio telescopes of modest size can't make out as much detail (have a lower resolution) than visible light telescopes. How do astronomers overcome this limitation? | we can connect several radio telescopes some distance apart |
| What was the major problem with the Hubble Space Telescope when it was first launched into orbit? | The most serious and notorious of these was an optical defect called spherical aberration, which was caused by the malfunction of a measuring device used during the polishing of the mirror. |
| Why do astronomers prefer to put infrared telescopes on high-flying airplanes or on satellites in space? | because the water vapor in the lower atmosphere is very good at absorbing infrared |
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