1
Q
What primarily causes the seasons?
A
The tilt of the Earth’s rotation axis relative to the ecliptic.
2
Q
How do the stars rise and set as seen from Orono?
A
The stars rise in the eastern half of the sky and set in the western half.
3
Q
What is the day with the most hours of daylight?
A
Summer solstice.
4
Q
How many constellations cover the entire celestial sphere?
A
88.
5
Q
What is the rotation of Earth primarily associated with?
A
The length of our day.
6
Q
Which apparent visual magnitude appears brightest in our sky?
A
A. -3.2.
7
Q
What is a bounded region of the celestial sphere best described as?
A
Constellation.
8
Q
Which planet has the most elliptical orbit around the Sun?
A
Mercury.
9
Q
What does the resolution of a telescope measure?
A
How far apart on the image objects appear.
10
Q
Where is Polaris as seen from Orono (latitude 44.9° N)?
A
It is fixed about halfway up in the sky.
11
Q
What is the term for when planets periodically change direction in their motion?
A
Retrograde motion.
12
Q
Which type of electromagnetic radiation has no window through Earth’s atmosphere?
A
X-rays.
13
Q
What concept is partly responsible for Mercury’s low nighttime temperature?
A
Mercury’s rotation rate.
14
Q
What are constellations that never set as seen from Orono called?
A
Circumpolar constellations.
15
Q
On what day is the sun highest in our sky at noon?
A
Summer solstice.
16
Q
During an annular eclipse, where is the sun in relation to the moon?
A
The Sun is visible in a ring around the Moon.
17
Q
Do images from reflecting telescopes have holes in them because of their secondary mirrors?
A
No, because light from all parts of every object strike all parts of the primary mirror.
18
Q
Where does Neptune move slowest in its orbit around the Sun?
A
When it is at aphelion.
19
Q
What are the physically largest telescopes?
A
Radio telescopes.
20
Q
What is the terminator on the Moon?
A
The boundary between light and dark.
21
Q
What is a cluster in astronomy?
A
A group of galaxies.
22
Q
What does the universe encompass?
A
All space/matter/energy that are detectable from Earth or will have an effect on Earth.
23
Q
What is the celestial sphere?
A
An imaginary sphere of which the observer is the center and on which all the celestial objects are considered to lie.
24
Q
What is an asterism?
A
A pattern of stars that we recognize in the night sky.
25
What is the origin of constellation names?
Greeks, Chinese, Arabs, German.
26
What does apparent magnitude indicate?
The more negative the magnitude, the brighter the star.
27
What is the brightest star?
Sun: -26.7.
28
What is the brightest star in the night sky?
Sirius (next to Orion's belt).
29
Where are the celestial poles located?
Directly over the North/South poles.
30
What is the horizon?
The boundary between Earth and sky.
31
What are circumpolar constellations?
Stars between the poles and horizon that never set.
32
What is the celestial equator?
The line on the celestial sphere directly above Earth's equator.
33
What are zodiac constellations?
Constellations the sun passes throughout the year.
34
What is the tilt of the Earth's axis?
23.5 degrees.
35
What are equinoxes?
Days with 12 hours of daylight and 12 hours of darkness.
36
When is the vernal equinox?
March 21.
37
When is the autumnal equinox?
September 22.
38
What are the solstices?
Summer: June 21st (sun highest in the sky), Winter: December 21st (sun lowest in the sky).
39
What creates seasonal temperature changes?
Combined rotation/revolution and higher concentration of light during hotter seasons.
40
When is perihelion?
January 3rd.
41
When is aphelion?
July 4th (farthest from the sun).
42
What affects temperature changes?
Tilt of the Earth's axis.
43
What are the phases of the Moon?
New, Waxing Crescent, First Quarter, Waxing Gibbous, Full, Waning Gibbous, Third Quarter, Waning Crescent.
44
What is the sidereal period of the Moon?
27 1/3 days.
45
What is the solar period?
A cycle of disturbances in the sun and its atmosphere, averaging about 11 years.
46
What is the synodic period?
29 1/2 days (new moon to new moon).
47
What is synchronous rotation?
When an object rotates at the same rate it revolves.
48
When do eclipses occur?
When the moon is in syzygy (conjunction or opposition).
49
What is Kepler's First Law?
The planets orbit around the sun in elliptical paths with the sun at one focus.
50
What is Kepler's Second Law?
The line between the sun and the planet sweeps equal areas in equal times.
51
What is Kepler's Third Law?
The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.
52
What is orbital inclination?
The angle between the plane of the ecliptic and the plane of the orbit of any object in the solar system.
53
What is the size of the solar system?
9 billion km.
54
What is the size of our galaxy?
1 x 10^18 km.
55
What is the size of a typical galaxy?
10^18 km.
56
What is the size of a cluster of galaxies?
10^20 km.
57
What is the age of the universe?
14 billion years.
58
What is the age of the Milky Way?
12 billion years.
59
What is the age of the solar system?
4.6 billion years.
60
What is the orbit time of Pluto?
250 years.
61
What is the orbit time of the sun around the Milky Way?
250 million years.
62
What is 1 AU?
1.5 x 10^8 km (average distance between Earth and Sun).
63
What is 1 parsec?
3.26 light years.
64
What is 1 light year?
10^13 km.
65
How many stars are in the galaxy?
Between 10^7 and 10^13.
66
What are asterisms?
Recognizable patterns made by stars within or among constellations.
67
What are declination and right ascension?
Latitude and longitude respectively in the sky.
68
What is aphelion?
When the sun is farthest from Earth (July).
69
What is perihelion?
When the sun is nearest to Earth (January).
70
What does apparent magnitude indicate?
It is logarithmic; 2.5 times (magnitude 2 = 2.5 times fainter than magnitude 1).
71
What is the ecliptic?
The plane of Earth's orbit or path of the sun across the sky.
72
What is the rate of the sun's apparent movement in the sky?
1 degree per day as Earth orbits west to east.
73
What is an equinox?
A day when day length equals night length, and the sun is on the celestial equator.
74
What is the vernal equinox?
The first day of spring.
75
What is the autumnal equinox?
The first day of fall.
76
What are the official beginnings of summer and winter?
Summer solstice (June 22, longest day), Winter solstice (December 22, shortest day).
77
What does sidereal mean?
With respect to stars.
78
What is a blue moon?
The second moon in one month.
79
What is the synodic period?
The orbit time of an object around the sun with respect to the Earth-sun line.
80
What is synchronous rotation?
When the interval of revolution equals the interval of rotation.
81
What is a lunar eclipse?
Earth's shadow on the moon.
82
What is a solar eclipse?
When the moon blocks the sun, revealing the sun's corona.
83
What is an annular solar eclipse?
When the moon is too small to cover the sun entirely, making the sun appear as a ring of light.
84
What is the maximum number of eclipses per year?
7 total (2 solar, 5 lunar).
85
Who proposed that orbits are heliocentric rather than geocentric?
Copernicus.
86
What is eccentricity?
A measure of how flattened an ellipse is (e=1 = completely flat, e=0 = perfect circle).
87
What is orbital inclination?
The tilt of an orbit from the ecliptic; most planets are near the ecliptic except Mercury (7 degrees).
88
What is planetary revolution?
All planets revolve counterclockwise when viewed from Polaris.
89
What did Kepler say about the speed of planets?
Planets go faster when close to the sun and slower when far from the sun.
90
What is retrograde rotation?
Clockwise rotation (e.g., Venus, Uranus, Pluto).
91
What is prograde rotation?
Counterclockwise rotation (all other planets).
92
What is retrograde motion?
A planet's apparent backward movement in the sky.
93
What is the Doppler shift?
The amount by which the wavelength of light is shifted by the Doppler effect.
94
What happens to waves from approaching objects?
They shorten (blueshift).
95
What happens to waves from receding objects?
They increase (redshift).
96
What improves resolution in telescopes?
A larger diameter opening leads to better resolution.
97
What are the two types of optical telescopes?
Refracting (uses lenses) and reflecting (uses mirrors).
98
What is a Newton telescope?
A telescope with a large curved mirror that focuses light.
99
What is a Cassegrain telescope?
A telescope where a secondary lens reflects light through a hole in the middle of the primary mirror.
100
What is a Coude telescope?
A telescope where a secondary lens reflects light to a tertiary lens, bouncing it to the side near the objective.
101
What is a prime focus telescope?
A telescope with no secondary mirror.
102
What is chromatic aberration?
The focusing of different colors of light at different distances behind a lens.
103
What is the fix for refractors with chromatic aberration?
Use a compound lens (achromat) to focus two colors to the same place.
104
What is spherical aberration?
The inability of a spherical mirror to focus all parallel rays to a single point.
105
What is the solution for spherical aberration?
Use a parabolic lens or mirror.
106
What is sagging in telescopes?
When glass is not strong enough; not a problem for reflectors.
107
What limits observing due to twinkling?
The atmosphere scatters and bends light from space.
108
What is an arcminute?
1/60 of an angle.
109
What is an arcsecond?
1/60 of an arcminute.
110
What limits observing due to atmospheric transparency?
Light is lost/scattered in the atmosphere, which makes the sky blue.
111
What limits observing due to angular limit?
Only a small part of the sky can be seen through a telescope.
112
What is adaptive optics?
Rapid change in mirror shape accounts for twinkling limit.
113
What is the difference between a camera and a CCD?
A camera has high resolution and low efficiency, while a CCD has smaller field and high efficiency.
114
What is a spectrograph?
A device that uses a prism to break up light and gain information on chemistry, physics, and velocities.
115
What are radio telescopes?
Telescopes that see through dust and gas, can be used in arrays.
116
What is a UV telescope used for?
To observe hot stars/gas.
117
What is an X-ray telescope used for?
To see supernovae, galaxies, the sun, black holes, and X-ray bursters.
118
What are gamma telescopes used for?
To observe very large explosions; they are not directional and cannot focus.
119
What are infrared telescopes used for?
To see star births; they need to be at high altitude to account for water vapor.
120
What is cosmogony?
The branch of science that deals with the origin of the universe, especially the solar system.
121
What is the primeval solar nebula?
The origin cloud from which the solar system formed.
122
What is angular momentum?
The inertia of rotation.
123
What is the nebular theory?
The theory that the sun and planets condensed out of a spinning cloud of gas and dust.
124
What are planetesimals?
Small planetary objects that form through gravity during the birth of a solar system.
125
What are protoplanets?
Regions of condensed matter that serve as a starting point for planet formation.
126
What are exoplanets?
Planets that circle a star other than our sun; over 2000 found so far.
127
What percentage of the solar system mass is the sun?
99.8%.
128
What is the order of the planets?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
129
What are terrestrial planets?
Earth-like planets (Mercury, Venus, Earth, Mars) that are small, dense, and rocky.
130
What are jovian planets?
Jupiter-like planets (Jupiter, Saturn, Uranus, Neptune) that are large and low density.
131
How many moons are in the solar system?
Over 160, most are small remnants from planetesimals.
132
What are dwarf planets?
Smaller, round objects that orbit the sun (e.g., Ceres, Pluto, Eris).
133
What are asteroids?
Rocky metallic objects that orbit the sun but are too small to be considered planets.
134
What are meteoroids?
Chunks of rock or dust in space smaller than asteroids.
135
What are comets?
Balls of ice, rock, and dust in space with a tail.
136
What is seeing in astronomy?
A measure of visibility in the atmosphere due to blurring and scattering.
ast 109
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