AST1002 Cumulative Exam
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119 terms
Terms | Definitions |
|---|---|
 The Solar day is longer than the sidereal day. | True. Solar day is 24hours and a sidereal day takes 3.9 more minutes. |
| If Earth rotated half as fast as it currently does, but its motion around the Sun stayed in same then... | The night would be twice as long |
| What causes the Earth's seasons? | 23.5 degree tilt on Earth's rotational axis |
| Sidereal Day | time it takes the earth to complete one rotation as measured by the stars |
| Solar Day | time it takes the sun to go from noon one day to noon the next. |
| Retrograde motion | Earth travels faster than the other outer planets to Earth's periodically overtakes the other planets making it appear as though the other planets stop and move backwards. |
| A major flaw in Copernicus's model was that it still had | circular orbits |
| If Earth's orbit around the Sun were twice as large as it is now, the orbit would take | more than two times to traverse |
| One light-year | distance that light travels in one year |
| Galileo's observation is significant because Jupiter's satellites show that... | the observation showed that bodies can orbit an object other than Earth |
| Modern telescopes use mirrors rather than lenses because | large lenses are more difficult to make, large lenses can be very heavy, mirrors can be computer controlled to improve resolution & light passing through lenses can be absorbed or scattered. |
| The MAIN reason professional observatories are built on the highest mountain tops is... | reduce atmospheric blurring |
| The MAIN reason that most professional research telescopes are reflectors it that... | mirrors produce sharper images that lenses do since there is no chromatic aberration |
| Which hero of the Renaissance postulated three "laws" of planetary motion? | Kepler |
| Kepler's 1st law of planetary motion | 1) planets orbit the Sun 2) orbits are elliptical in shape 3) orbits are noncircular 4) applies to all orbiting objects |
| Kepler's 2nd law | a planet moves faster when closer to its star |
| Copernican Revolution | choose a heliocentric view over a geocentric view |
| Galileo | 1) observed the moons of Jupiter 2) observed Venus has phases |
| Occam's Razor | the simplest theory, is always the right answer |
| Ptolemaeus (Ptolemy) | constructed the best geocentric model-each planet orbits Earth, and at the same time moves in circles about that orbit |
| Aphelion | farthest point from the sun |
| Perihelion | closest point from the Sun |
| Kepler's 3rd Law | The square of a planet's orbital period (Earth years) is proportional to the cube of its semimajor axis (AU) |
| Newton's First Law of Motion | An object at rest remains at rest and a moving object continues to move forever in a straight line with constant speed, uunless some external force changes their state of motion |
| Newton's 2nd Law | Acceleration of an object os directly proportional to the net applied force and inversely proportional to the object's mass |
| Newton's 3rd Law of Motion | To every action there is an equal and opposite reaction |
| Let's say Earth has the same mass, but is half the radius. How does the force of gravity change? | Half the radius then, for the same mass means four times the gravity. The gravitational force is inversely proportional to the square of the distance |
| You throw a baseball to someone; before the ball is caught, it is temporarily in orbit around Earth's center? | true |
| The leading theory of solar system formation is... | The planets formed from the same flattened, swirling gas cloud that formed the Sun. |
| What is the number of confirmed planets beyond our solar system? | more than 300 |
| Terrestrial planets (earth-like) | Mercury, Venus, Earth and Mars |
| Most asteroids are found | between Mars and Jupiter |
| The planet with the largest diameter in our solar system is | Jupiter |
| The overall shape of the orbits of most the planets | is slightly elliptical, but nearly circular |
| Sunlight absorbed by Earth's surface is re-emitted in the form of | infrared raditation |
| If Earth has no moon, then tides would | occur with the same frequency, but would not be as strong. The Sun also affects the tide but lesser than the moon. |
| The most likely theory of the formation of the moon is... | formed from a collision of Earth with a Mars-sized object |
| The region around Earth where the magnetic field traps charged particles is the... | Van allen radiation belts |
| Which of these gases is least abundant in our atmosphere? | hydrogen |
| Terrestrial planets have one or no moon. | ... |
| The Jovian planets have large number of moons. | ... |
| Jovian planets share | 1) many moons 2) large magnetic fields 3) lots of hydrogen &helium gas 4) differential rotation 5) have much thicker |
| Mercury's solar day is longer than its solar year | true |
| Feature of Venus? | that the temperature on the surface does not change significantly between day and night |
| Jupiter's bright zones are cloud streams made of ___________ ice crystals. | Ammonia |
| Venus's surface is permanently obscured by clouds. So it has been mostly studied by... | orbiting satellits using radar |
| Jupiter has a large magnetosphere and strong magnetic field | ... |
| The vastly different atmospheric character of Mars is likely due to... | a reverse greenhouse effect |
| The most famous and long lasting storm in the solar system is Jupiter's | Red Spot |
| Jupiter's atmosphere is mostly | hydrogen |
| What effect does the greenhouse effect have on the surface environment of Venus? | to raise the surface temperature by hundreds of degrees |
| From Earth Venus is the brightest then Jupiter | ... |
| A feature of MArs which distinguishes it from the other planets is | the dust storms |
| Why did the Soviet spacecraft survive for only a few minutes on the Venusian surface? | The conditions of extreme pressure, corrosive atmosphere, and high temperatures severely damage it. |
| The most likely explanation for the retrograde rotation of Venus is... | impact of a massive object on it early in its history |
| Both Jupiter and Saturn | 1) emit more energy than they absorb from the Sun 2) have liquid metallic hydrogen in their interiors 3) rotate very rapidly than the terestial planets 4) have rings |
| The seasons on Uranus: Its strange tilt produces extreme seasonal variations | ... |
| Saturn is the least dense of the planets, and could float on water | ... |
| Neptune has the Great _____ spot | Dark |
| Saturn's rings exist because they lie within the plane†'s Roche limit | ... |
| Triton's orbit is unusual because it is retrograde | ... |
| Io's surface appears very smooth bc... | is continuously by volcanic activity |
| The Galilean moons of Jupiter are sometimes described as a miniature inner solar system bc... | the moon's densities decreases with increasing distance from Jupiter |
| What future awaits Triton, the largest satellite of Neptune? | tidal breakup as it spirals closer to Neptune |
| What is the Dynamo theory? | The magnetic field of Earth is caused by the spinning electrically conductive metal core of the planet |
| Uranus and Neptune magnetic fields are offset from the planet's centers | ... |
| The formaton of Jupiter and its moons may have mimicked on a small scale the formation of the Sun and the interior planets | ... |
| Jupiter's moon's unique qualities. Titan Io Europa Triton | Titan= has nitrogen atmosphere like earth's early atmosphere Io= has volcanic activity Europa= appear to have water Triton= completely doomed, within roche limit of Neptune |
| Reading Music Is Very Unsatisfying for Xylophones and Glockenspiels | Radio, Microwave, Infrared, Visible, Ultraviolet, X-Ray and Gammaray |
| absolute temperature cannot be negative (-30K) | ... |
| the lower the temperature the longer the wavelength. higher the temperature the shorter the wavelength. | ... |
| What is the most abundant element in the Sun? | Hydrogen |
| Compared with Earth's diameter, the Sun's diameter is about... | 100 times larger |
| What is the primary source of the Sun's energy? | fusion of light nuclei to make heavier ones |
| The density of the Sun is most similar to that of?? | Jupiter |
| The proton-proton cycle involves what kind of fusion process? | hydrogen into helium |
| How long does it take for a photon to escape from the solar core? | about a million years |
| how much mass will the sun lose to space during its lifetime, through the solar wind? | a few thousandths of its total mass |
| What is a neutrino | an elusive, subatomic particle having little mass, difficult to detect. |
| To determine the radius of a star, you must know what? | luminosity and temperature |
| The mass of a star may be determined | by studying its orbit around a binary companion |
| how hot is the core of the sun? | 15,000,000K |
| What is luminosity? | the amount of radiation (energy) leaving a star per unit of time. |
| What's a Giant? | starts with radii between 10-100 times that of our sun |
| What's a dwarf? | anything smaller in radius than our sun |
| What is the single most important characteristic determining the course of a star's evolution? | mass |
| Why is dust important to solar system formation? | 1) it radiated in the infr-red which helps to cool the cloud down 2) it provides a platform on which additional material can "climp" up |
| The Earth has a solid, dense, nickle-iron core | ... |
| The temperature at the center of Earth is approx the same as the surface of the sun | ... |
| Seismis waves are how we learned about the Earth's structure | ... |
| Concerning the Earth's greenhouse effects... | The concentration of CO2 in the atmosphere has been increasing since the start of the industrial revolution |
| Which of these is the smallest of the terrestrial world? | Mercury |
| Mercury has the largest eccentricity of the Terrestial worlds | ... |
| Mercury has the largest angle to the plane of the rest of the solar system | ... |
| The atmosphere of Mars.. | mostly nitrogen like Venus and much less dense than Earth's |
| What is absolute zero? | The temperature at which all thermal motion stops |
| Magnitude for the temperature for the center of the sun | 10,000,000K |
| The Radiation zone is... | A region of the sun where the material is mainly ionized. A region where photons can travel through relatively freely |
| As few as two wavelength measurements can be used to estimate the temperature of a star. | True |
| What is plotted on the HR diagram? | Luminosity and Temperature |
| As the distance of an object increases the parallax decreases | ... |
| Red giants | are larger and cooler than our sun |
| What is the ultimate stage of our star | to become a black dwarf |
| Galaxies merging causes | star formation and destruction of spiral arms |
| why do typw 1 supernovae provide signposts for large distances? | they all have the same absolute luminosities |
| Hubble Law | relates galatic recession velocity to the distance to the galaxy in question |
| What is driving the expansion of the universe? | Dark energy |
| Nuclear fusion in the core of a massive star cannot create elements much heavier than iron. | This is true. |
| The Sun will get brighter as it begins to run ot of hydrogen (fuel) in its core | ... |
| White dwarf is supported by the pressure of tightly packed- electrons | ... |
| All things , included light are attracted by gravity | ... |
| What is general relativity? | The warping of space, or curving by matter. |
| The lighthouse model explains how... | a rotating neutron star generates an observable beam of light |
| most pulsars are observed as radio sources | ... |
| What is the event horizon of a black hole? | "surface" from inside of which nothing can escape |
| As a spaceship's velocity gets closer to the speed of light | its length will decrease and its clock will run more slowly |
| Due to the density and collisions among galaxies, ___________ are rare in the centers of clusters. | spirals |
| Where is dark matter located? | dark matter appears to be concentrated in spherical haloes around galaxies but extends far beyond the visible matter |
| the diamete of the Milky Way is | 30kpc |
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