Term
How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it is
on Saturn at 10 AU? (gravitational pull refers to the acceleration due to gravity on the planet) |
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Definition
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Term
| A star with a declination of +40.0 degrees will be |
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Definition
| north of the celestial equator. |
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Term
| If a wave’s frequency doubles, its wavelength |
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Definition
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Term
| What problem do refractor telescopes have that reflectors don’t? |
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Definition
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Term
| Planetary orbits (in our solar system) |
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Definition
| are almost circular, with low eccentrities. |
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Term
| At what phase(s) would you expect to find extremely high and low tides? |
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Definition
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Term
| If the Earth were in an orbit farther from the Sun than it is now, |
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Definition
| the year would be longer. |
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Term
| Which answer has these colors in order from the longest wavelength to the shortest? |
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Definition
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Term
| What is the resolution of a telescope? |
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Definition
| Its ability to distinguish two adjacent objects close together in the sky |
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Term
| A blackbody has a temperature of 1,000 K and emits mostly |
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Definition
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Term
If an electric field wave oscillates north and south (horizontally), and the electro-
magnetic wave is traveling vertically straight up, then what direction does the magnetic field wave
oscillate? |
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Definition
| East and west (horizontally) |
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Term
| When a thin crescent of the Moon is visible just before sunrise, the Moon is in its |
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Definition
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Term
Which of the following stellar properties can you estimate simply by looking at a
star on a clear night? |
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Definition
| Both brightness and surface temperature |
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Term
Green light has a shorter wavelength than orange light. In a 5-inch telescope, green
light will |
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Definition
| provide better angular resolution than orange light. |
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Term
Kepler’s first law worked, where Copernicus’ original heliocentric model failed,
because Kepler described the orbits as |
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Definition
| elliptical, not circular. |
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Term
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Definition
| a streak of light in the atmosphere. |
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Term
| Atoms have particular associated spectral lines because |
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Definition
| electrons have only certain allowed orbits. |
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Term
| The best test of a scientific hypothesis is how |
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Definition
| well it predicts new observations. |
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Term
The temperature scale that places zero at the point where all atomic and molecular
motion ceases is |
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Definition
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Term
| The average rate of erosion on the Moon is far less than here because |
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Definition
| the Moon lacks wind, water, and an atmosphere. |
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Term
| The tail of a comet always points |
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Definition
| away from the Sun and becomes longest and brightest at perihelion. |
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Term
| Compared to optical photons |
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Definition
1. radio photons have a longer wavelength.
2. X-ray photons have a larger frequency.
3. infrared photons have a smaller energy. |
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Term
| As a rotating gas cloud contracts, it spins |
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Definition
| faster due to conservation of angular momentum. |
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Term
| The Kuiper Belt is found where in the solar system? |
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Definition
| Beyond the orbit of Neptune |
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Term
| In noting that the Earth is “differentiated”, we mean that |
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Definition
| the density increases as you descend downward toward the core. |
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Term
| Relative to the comet, the direction of the ion tail tells us |
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Definition
| the direction of the Sun. |
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Term
| What will occur when the full Moon is on the ecliptic? |
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Definition
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Term
| Why do Mercury and the Moon have almost no atmosphere? |
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Definition
The gravity at their surfaces is low, so most gas molecules travel fast enough to escape the
planet. |
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Term
The observed spectral lines of a star are all shifted towards the red end of the
spectrum. Which statement is true? |
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Definition
| This is an example of the Doppler effect. |
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Term
What would the days and seasons be like if the Earth still rotated at the same
speed, but the Earth’s axis were tilted nearly 80 degrees on its side instead of 23 degrees? |
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Definition
The days and seasons would be the same lengths as ours, but the seasons would have more
extreme temperature changes. |
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Term
| If a wave’s frequency is halved, its wavelength |
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Definition
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Term
| A blackbody has a temperature of 6,000 K and emits mostly |
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Definition
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Term
Blue light has a shorter wavelength than orange light. In a 5-inch telescope, blue
light will |
|
Definition
| provide better angular resolution than orange light. |
|
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Term
| The Sun is a stable star because |
|
Definition
| gravity balances forces from pressure. |
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Term
| What is thought to cause Io’s volcanism? |
|
Definition
| Tidal stresses from both Jupiter and Europa |
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Term
| The magnetic fields of which two planets are most unusual? |
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Definition
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Term
Rigel has an apparent magnitude of +0.18 and Betelgeuse an apparent magnitude of
+0.45. What can you conclude from this? |
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Definition
| Rigel is brighter than Betelgeuse. |
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Term
| Some regions along the plane of the Milky Way appear dark because |
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Definition
| stars in that region are hidden by dark dust particles. |
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Term
| The critical temperature the core must reach for a star to shine by fusion is |
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Definition
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Term
| Interstellar dust clouds are best observed at what wavelength? |
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Definition
|
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Term
| Which are the four Galilean moons of Jupiter? |
|
Definition
| Io, Europa, Ganymede, and Callisto |
|
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Term
|
Definition
| large moons are torn apart. |
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Term
| A cloud fragment too small to collapse into a main sequence star becomes a |
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Definition
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Term
| A moon with a smooth, uncratered surface would imply |
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Definition
| the surface is very young. |
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Term
| How do the atmospheres of Earth’s Moon and Mercury compare? |
|
Definition
| Neither body has a permanent atmosphere. |
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Term
| On the H-R diagram, red supergiants like Betelgeuse lie |
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Definition
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Term
The reason the Jovian planets lost very little of their original atmosphere is due to
their |
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Definition
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Term
| A solar-mass star will evolve off the main sequence when |
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Definition
| it builds up a core of inert helium. |
|
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Term
| Today, the primary source of the Sun’s energy is |
|
Definition
| the strong force fusing hydrogen into helium. |
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Term
| Of the elements in your body, the only one not formed in stars is |
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Definition
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Term
| A star will spend most of its life |
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Definition
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Term
| Emission nebulae like M-42 occur only near stars that emit large amounts of |
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Definition
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Term
| Stellar parallax is used to measure the |
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Definition
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Term
The speed of light is 3 · 108 m/s. If 2.00 kg of mass is converted to energy, how
much energy will be produced? |
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Definition
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Term
| A star’s apparent magnitude is a number used to describe how our eyes measure its |
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Definition
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Term
| What would Jupiter have needed to be a star? |
|
Definition
| More mass to make the planet hotter |
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Term
The parallax of a certain star was found to be 0.01 arc-seconds. Find the distance
to this star in pc. |
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Definition
|
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Term
| The temperature of the Sun’s photosphere is about |
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Definition
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Term
| A star’s color index directly tells us its |
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Definition
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Term
| Many astronomers believe Pluto is perhaps best classified as |
|
Definition
| a large Kuiper Belt object. |
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Term
The number of sunspots and solar activity in general peaks
1. every 27 days, the apparent rotation period of the Sun’s surface. |
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Definition
|
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Term
| Which moon in the solar system shows a dense atmosphere? |
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Definition
|
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Term
| Interstellar gas is composed primarily of |
|
Definition
| 90% hydrogen, 9% helium, and 1% heavier elements. |
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Term
| Stars are often born within groups known as |
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Definition
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Term
| What can be said with certainty about a red star and a blue star? |
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Definition
| The blue star is hotter than the red star. |
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Term
| A star near the lower right of the H-R diagram is likely to be |
|
Definition
| red, with low luminosity. |
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Term
|
Definition
Tiny particles in the air are more efficient at scattering short-wavelength light than they are
at scattering long-wavelength light. |
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Term
| Type II supernovae occur when their cores start making |
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Definition
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Term
| Homogeneity and isotropy, taken as assumptions regarding the structure and evolution of the universe, are known as |
|
Definition
| the cosmological principle. |
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Term
| The concept that the direction of observation does not matter overall is |
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Definition
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Term
| The concept that on the grandest of scales, the universe is similar in appearance everywhere is |
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Definition
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Term
| Because almost all galaxies show redshifted spectra, we know that |
|
Definition
| the universe is expanding. |
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Term
| The darkness of the night sky in an infinite universe is addressed in |
|
Definition
|
|
Term
| Interstellar gas is composed mainly of |
|
Definition
| 90% hydrogen, 9% helium by weight. |
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Term
| What effect does even thin clouds of dust have on light passing through them? |
|
Definition
| It dims and reddens the light of all more distant stars. |
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Term
| Which statement about the dark nebulae is true? |
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Definition
| They can be penetrated only with shorter waves, such as UV and x-ray. |
|
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Term
| Some regions along the plane of the Milky Way appear dark because |
|
Definition
| stars in that region are hidden by interstellar gas |
|
|
Term
| Due to absorption of shorter wavelengths by interstellar dust clouds, distant stars appear |
|
Definition
|
|
Term
| Which statement is true about the interstellar medium? |
|
Definition
| Dust blocks the longest electromagnetic wavelengths. |
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Term
| Spectra of interstellar gas show it has the same basic composition as |
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Definition
|
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Term
| What is the primary visible color of an emission nebula? |
|
Definition
| red due to ionized hydrogen atoms |
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