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Question |
Answer |
Page |
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1.
|
Who attempted the first astronomical measurement
and what was it? |
Aristarchus, the angle
between the sun and the moon |
3 |
|
2.
|
As evidence suggests, what two ancient
civilizations were probably expert astronomers? |
Sumerians and Greeks |
3 |
|
3.
|
What did Aristarchus theorize about the positions
and movements of the sun and planets? |
that the sun was the center
of the universe and all the planets orbited around it (heliocentric
theory) |
3 |
|
4.
|
Wht did Erastonsthenes calculate and when? |
the diameter of the earth in
the 2nd century BC |
3 |
|
5.
|
Who discovered the “precession of the equinoxes”
and what was it? |
Hipparchus of Rhodes, it
involves the coning of the earth’s axis (due to the degree of its tilt
and the gravitational pull of various objects on the equatorial bulge)
that changes which star becomes the North Star, for example, as well as
the positions of constellations over the course of 26,000 years |
3,
see p. 20 as well |
|
6.
|
What did the discovery of the precession of the
equinoxes allow Hipparchus to do with the system of navigation used by
mariners? |
he modernized the geocentric
navigation system that mariners used to locate themselves according to
the stars because the precession allowed for more accurate predictions
of the planets and stars |
3 |
|
7.
|
What is heliocentric rotation? |
rotation around the sun; the
theory that the sun is the center of the universe and the planets are
all orbiting around it |
3 |
|
8.
|
Who produced “incredibly accurate maps of the
ancient world” and how? |
Claudius Ptolemy, by using
systematized trigonometry |
3 |
|
9.
|
What civilization created a 5-constellation
universe catalogue and what was it used for? |
ancient Egyptians; used (by
grouping stars) to create calendars; maps of the sky were used to align
the pyramids |
3 |
|
10.
|
What civilization was the first to keep detailed
records of the paths of the planets and why? |
the Babylonians; they thought
the paths of the planets would aid them in predicting the future
(divination) |
3 |
|
11.
|
Who was the first to propose the theory of
heliocentric rotation? Who generally gets credit? |
Hipparchus of Rhodes;
Copernicus |
3 |
|
12.
|
Who proved the paths of planets were elliptical?
When? |
Johannes Kepler; around 1600 |
3 |
|
13.
|
What other subjects do astronomers study to
understand the universe? |
physics, geology, chemistry,
cosmology |
5 |
|
14.
|
What two main reasons caused ancients to develop
incorrect ideas about astronomy? |
they didn’t understand laws
of motion (like gravity) and their measurements weren’t as
accurate/didn’t reveal planetary movement in enough detail |
|
|
15.
|
What was Aristotle’s system to explain the
movements of the stars, moon, and planets? When was it developed? |
he devised a 56-shell/sphere
system in the 300s BC; earth was fixed in the center; stars were in the
last shell; and the shells rotate inside one another to account for
various planetary motions (e.g., prograde and retrograde motion) |
6 |
|
16.
|
Who offered a better explanation for retrograde
motion in the 100s AD and what was it? |
Claudius Ptolemy, he came up
with a system of epicycles and deferents; each individual planet moved
in a small circle called an epicycle while also moving in a large circle
around the earth called a deferent; earth was near the center of all
deferents |
6 |
|
17.
|
Who developed the theory that the sun (rather than
the earth) was the center of the universe in the 1500s? What 2
phenomena did this theory best explain? |
Nicolaus Copernicus; it best
explained retrograde motion and the east-west movement of the sun and
stars across the earth’s sky |
6 |
|
18.
|
Whose measurements of planetary movements did
Kepler use to create his first 2 laws of planetary motion? |
Tycho Brahe, a Danish
astronomer (measurements made/taken c. 1590-1600) |
6 |
|
19.
|
What did Kepler’s 3 laws of planetary motion
explain? When were they published? |
1st and 2nd
laws, published 1609, explain that planets orbit in an ellipse around
the sun which is at a key point inside the ellipses (studied Mars to
conclude this) and that the relationship between the distance from the
sun and the speed at which the planets travel applies to all planets;
3rd law, published
1619, shows that the size of a planet’s orbit relates to the time it
takes to orbit |
6 |
|
20.
|
Who built and used the first optical telescope? |
Galileo |
6 |
|
21.
|
Name 4 ways in which modern astronomers gather
information. |
1.
they study celestial objects by using telescopes
2.
they study cosmic rays and neutrinos
3.
they study chunks of matter that have landed on earth from outer
space
4.
they send spacecraft up to study celestial objects up close |
6 |
|
22.
|
Approximately how many asteroids revolve around the
sun and where are most located? |
more than 50,000; most
located between the orbits of Mars and Jupiter |
6 |
|
23.
|
How many miles is a light-year? |
5.88 trillion miles (9.46
trillion km) |
7 |
|
24.
|
What is the nearest star and how close is it to
earth? |
Proxima Centauri, 4
light-years away |
7 |
|
25.
|
How big is the Milky Way? |
about 100,000 light-years
across |
7 |
|
26.
|
How far is the sun from the Milky Way’s center? |
about 25,000 light-years from
its center |
7 |
|
27.
|
What galaxy is closest to the Milky Way and how far
is it? |
Andromeda Galaxy; 2 million
light-years |
7 |
|
28.
|
What does AU stand for and what is it? |
Astronomical Units; it’s the
average distance between the earth and the sun, which is 93 million
miles (150 million km, or 8 light-minutes) |
7 |
|
29.
|
What is the average distance between the sun and
Pluto? |
39.5 AU |
7 |
|
30.
|
What unit of measure do astronomers use to talk
about extremely long distances? How big is it? |
parsec; 3.26 light-years |
7 |
|
31.
|
What is longitude called in the celestial
coordinate system? |
right ascension |
7 |
|
32.
|
What is latitude called in the celestial coordinate
system? |
declination |
7 |
|
33.
|
Which is positive: latitude north of the celestial
equator or latitude south of it? |
north is positive |
7 |
|
34.
|
How and in how many ways have astronomers divided
the sky? |
they’ve divided it into 88
constellations |
7 |
|
35.
|
How are the stars within a constellation identified
and labeled? |
they are identified by how
bright they are following the Greek alphabet; the brightest star is
labeled “alpha,” the second brightest “beta,” and so on |
7 |
|
36.
|
How are fainter stars within a constellation
labeled? |
after the 24 Greek letters
are used up, astronomers use a numeric system to label the fainter stars |
7 |
|
37.
|
What are variable stars? How are they labeled? |
they are stars that vary in
brightness; they are labeled with Roman letters |
7 |
|
38.
|
What two ancient concepts do astronomers still use
to specify the locations of celestial objects? |
the constellations and the
celestial sphere |
7 |
|
39.
|
What is electromagnetic radiation and what is one
example of it? |
waves of electric and
magnetic energy; visible light is one example |
7 |
|
40.
|
What is wavelength? |
the distance between
successive crests in a wave |
7 |
|
41.
|
List the forms of electromagnetic radiation from
shortest wavelength to the longest. |
gamma rays, x-rays,
ultraviolet rays, visible light, infrared rays, radio waves; together
they make up the electromagnetic spectrum |
7 |
|
42.
|
What is frequency? |
it is how frequently a wave
crests at a particular point within a particular time period |
7 |
|
43.
|
What unit is used to measure frequency? What does
it represent? |
Hertz (Hz)
it represents one crest
passing through one point during one second |
7 |
|
44.
|
How do wavelength, frequency, and energy in
radiation relate? Give an example. |
they are all related to each
other; for example, if you have a short wavelength, you’ll have a high
frequency and a high energy; if you have a long wavelength, you’ll have
a low frequency and a low energy |
7 |
|
45.
|
What are particles of energy called? |
photons |
7 |
|
46.
|
What is optical astronomy? |
study of the heavens by
detecting and analyzing visible light |
7 |
|
47.
|
What is the range of wavelengths for visible light
and what colors are associated with them? |
deep red (700 nm) and deep
violet (400 nm) |
7 |
|
48.
|
How does telescope lens size and brightness of
celestial objects relate and why? |
the brighter the celestial
object, the easier it is to see, so you don’t need a lens that’s very
big in order to observe it; however, fainter objects need to be viewed
with a telescope lens of a much larger size so that the lens can capture
more of the incoming light from that faint object so they can be send |
7 |
|
49.
|
Where are the largest all-purpose telescopes and
how big are they? |
there are two twin telescopes
(Keck telescopes) on Mauna Kea, a volcano in Hawaii; each has a mirror
that is 33 feet in diameter |
7 |
|
50.
|
Why are telescopes mounted on mountains? |
these locations are chosen
because they are above most of the earth’s atmosphere; this is important
because refraction and movement of particles in the atmosphere cause
atmospheric blurring which distorts the images of celestial objects;
putting telescopes above most of the atmosphere reduces the amount of
distortion |
7-8 |
|
51.
|
Why do stars appear to twinkle when viewed from
earth? |
because of atmospheric
blurring and refraction |
8 |
|
52.
|
What is the Hubble Space Telescope and what are
some significant dates and statistics associated with it? |
it is the largest orbiting
telescope ever; it was launched in 1990, repaired in 1993, and upgraded
in 1997; it’s main lens is 94 inches in diameter and it can produce
images that are 5x more detailed than any earth-bound telescope |
8 |
|
53.
|
Why do astronomers study photographs from
telescopes? |
well aside from the obvious
which is it allows them not to have to sit glued to a telescope all the
time, the telescope can allow for long exposure times which can capture
objects too faint to see with the naked eye |
8 |
|
54.
|
When did astronomers start photographing images
through telescopes? |
around 1850 |
8 |
|
55.
|
What has film been replaced by and why? |
a charge-coupled device (CCD);
it is 50x more sensitive to light than film |
8 |
|
56.
|
What is spectroscopy? |
the study of incoming
radiation by breaking it down into parts according to its spectrum
(visible light’s spectrum = ROY G BIV) |
8 |
|
57.
|
What discovery is spectroscopy based on? When was
this discovery made and by whom? |
the spectrum of the colors of
sunlight contains dark lines where specific colors are absent;
this discovery was made in
1814 by German optician Joseph von Fraunhofer |
8 |
|
58.
|
What kind of non-color lines do the spectrums of
stars’ light have? |
dark ones |
8 |
|
59.
|
What kind of non-color lines do the spectrums of
light from hot gasses have? |
light ones |
8 |
|
60.
|
Do forms of electromagnetic radiation (other than
visible light) from celestial objects have spectral lines? |
yes |
8 |
|
61.
|
What does studying spectral lines tells us about a
celestial object? |
its density, its temperature,
and its chemical composition |
8 |
|
62.
|
How is it possible for spectral lines to tell us so
much about a celestial object? |
well, for example, dark
spectral lines indicate places where energy from the radiation has
passed through various atoms and been absorbed; electrons absorb that
energy to jump up a level and leave a line in the radiation from where
they stole that energy; each particular atom has its own particular
pattern of spectral lines for a given temperature range |
8 |
|
63.
|
What are absorption lines and who first discovered
them? |
they are dark lines in a
radiation’s spectrum where energy has been absorbed by atoms the
radiation has passed through; Joseph von Fraunhofer discovered them in
1814 |
8 |
|
64.
|
What are emission lines? |
bright lines in a radiation’s
spectrum where energy has been emitted/added by atoms the radiation has
passed through (in this case, the electrons have given off energy to
jump down a level) |
8 |
|
65.
|
What was confirmed about the sun by a study of
emission lines done in the 1940’s? |
that the outer part of the
sun (its corona) burns at a temperature of millions of degrees |
8 |
|
66.
|
What color are “cool” stars? |
reddish |
8 |
|
67.
|
What color are “hot” stars? |
blue-white |
8 |
|
68.
|
What is the Doppler effect? |
it’s a shift in frequency of
sound or a spectral shift in electromagnetic radiation emitted by a
source moving toward or away from an observer |
8 |
|
69.
|
Whish way do spectral lines shift if an object is
approaching the observer? |
toward the blue (blueshift) |
8 |
|
70.
|
Which way to spectral lines if the object is moving
away from the observer? |
toward the red (redshift) |
8 |
|
71.
|
What else can spectroscopy, by studying shifts in
spectral lines, reveal for astronomers? |
the distance of the object
emitting the radiation |
8 |
|
72.
|
What did Edwin Hubble discover using spectral
shifts? |
in 1929, Hubble discovered
that the further away a galaxy was, the faster it is retreating, and
thus the greater the redshift in its spectrum; thus measuring a galaxy’s
redshift reveals how far away it is |
8 |
|
73.
|
Explain interferometry. |
interferometry is an optical
technique used to produce very detailed images of celestial objects; it
works like this: a star emits a ray of light that hits one telescope’s
lens at a certain point and angle; the same star emits another ray of
light that hits another telescope’s lens at a certain point and angle; a
computer synthesizes this information to produce an image of the object
or, for example, to determine the size of the star |
8 |
|
74.
|
What phenomenon does interferometry use? |
interference |
8 |
|
75.
|
When rays are combined in interferometry, what is
produced? |
a series of bright and dark
bands called an interference pattern |
8 |
|
76.
|
What 3 special techniques developed by optical
astronomers are also used in other areas of astronomy? |
spectroscopy, interferometry,
and adaptive optics |
8 |
|
77.
|
What does adaptive optics do for optical astronomy? |
it reduces/eliminates the
effects of atmospheric blurring |
8 |
|
78.
|
How does adaptive optics work? |
a telescope must be fitted
with a regular mirror that then reflects the light to a deformable
mirror; the deformable mirror can change (as much as several hundred
times each second) to counteract the effects of atmospheric blurring;
another telescope and computer analyze the atmosphere and send that
information to the telescope with the deformable lens so the pistons in
the telescope can change the lens |
8 |
|
79.
|
What celestial objects are best studied using the
infrared spectrum? |
cool stars, newly-forming
stars, and planets & other objects that reflect light |
9 |
|
80.
|
What is the range of wavelengths in the infrared
spectrum |
700 nm to 1 millimeter; or .7
micrometers to 1,000 micrometers |
9 |
|
81.
|
Why didn’t infrared astronomy develop fully until
the 1960s? |
most infrared photons don’t
have enough energy to cause the chemical reaction to produce images on
film; electronic sensors needed to be developed to produce infrared
images |
9 |
|
82.
|
What’s one big problem with trying to study
infrared astronomy from earth? |
most infrared rays get
absorbed by the earth’s atmosphere |
9 |
|
83.
|
What role does water vapor play in the earth’s
atmosphere when it comes to infrared astronomy? |
it is one of the biggest
absorbers of infrared in the earth’s atmosphere |
9 |
|
84.
|
Name 2 notable infrared telescopes, where they are
on earth, and why is that a good location. |
Infrared Telescope Facility
of NASA and the United Kingdom Infrared Telescope;
both are on Mauna Kea in
Hawaii and that’s a good location because they telescopes are positioned
above most of the water vapor in the earth’s atmosphere |
9 |
|
85.
|
What infrared project launched in 1997? Who
directed it? What does it involve? |
2MASS (Two Micron All-Sky
Survey), directed by the University of Massachusets; it involves two
telescopes, one on Mount Hopkins in Tucson, AZ and one on Cerro Tolol in
Chile mapping the earth’s sky at a wavelength of 2 micrometers |
9 |
|
86.
|
When was the Infrared Astronomical Satellite (IRAS)
launched, how long did it orbit, what did it do, and who did it belong
to? |
IRAS was launched in 1983; it
orbited for 10 months, mapping infrared radiation across the entire sky;
it was a multinational project. |
9 |
|
87.
|
When was the Infrared Space Observatory in
operation, who did it belong to, and what did it do? |
from 1995-1998; it was a
European spacecraft, and it picked up where IRAS left off with mapping
infrared radiation across the entire sky |
9 |
|
88.
|
What was the Cosmic Background Explorer, what did
it do, and when was it in operation? |
COBE was a satellite that
mapped the sky at the longest infrared wavelength; it was in operation
during 1989 and 1990 |
9 |
|
89.
|
What device was installed on the Hubble Space
Telescope in 1997? |
the Near Infrared
Camera/Multi-Object Spectrometer |
9 |
|
90.
|
Why are orbiting infrared telescopes so short
lived? |
they need to be cooled to
keep their own infrared radiation from interfering with the infrared
they are trying to detect; this requires artificial coolant, so the
telescope can only work for as long as it has coolant; the telescope
must be cooled to the temperature of liquid helium—about 4 degrees
Celsius about absolute zero (-459.67 degrees F or -273.15 degrees C) |
9 |
|
91.
|
What is the range of wavelength in radio waves? |
1 millimeter and up |
9 |
|
92.
|
How do astronomers use radio waves? |
they use them to produce
images of the objects emitting them and to study the objects
spectroscopically |
9 |
|
93.
|
Do radio waves easily pass through earth’s
atmosphere? |
yes if they are between 1 mm
and 10 m |
9 |
|
94.
|
Name some of the objects astronomers receive radio
signals from. |
particles in the magnetic
field of Jupiter, gas clouds orbiting the center of the Milky Way,
pulsars, distant galaxies, and quasars |
9 |
|
95.
|
What are pulsars? |
rapidly spinning collapsed
stars |
9 |
|
96.
|
What do astronomers believe power quasars? |
an enormous black hole at the
center of the galaxy |
9 |
|
97.
|
Who discovered radio waves from outer space and
when? |
Karl Jansky (American) in
1931 |
9 |
|
98.
|
When did radio astronomy develop? |
after 1945 (after WWII) |
9 |
|
99.
|
Describe how a radio telescope differs from other
telescopes. |
a radio telescope is a dish
antenna and its surface does not need to be extremely smooth because the
wavelengths of radio waves are so large |
9 |
|
100.
|
What does wavelength have to do with how a
telescope is made? |
the shorter the wavelength of
the incoming radiation to be detected, the smoother the surface of the
lens or mirror has to be; the longer the wavelength, the smoothness
isn’t as important; hence, radio telescopes can be made of mesh metal |
9 |
|
101.
|
What unit of measure do infrared astronomers use
when talking about wavelength? |
micrometers |
9 |
|
102.
|
What unit of measure do optical astronomers use
when talking about wavelength? |
nanometers |
9 |
|
103.
|
Where is the largest radio telescope, can it be
steered (why or why not), and how big is it? |
it is in Arecibo, Puerto
Rico, and it cannot be steered because it was formed by covering a
natural bowl in the ground with mesh metal; it is 1,000 feet (305 m) in
diameter |
9 |
|
104.
|
Where are the largest steerable radio telescopes
and how big are they? |
one is in Effelsberg, Germany
and the other is in Green Bank, West Virginia; they are each 328 feet
(100 m) in diameter |
9 |
|
105.
|
Why is interferometry most useful in radio
astronomy? |
for interferometry to work,
the telescopes receiving the radiation must be a certain fraction of a
distance apart, and that distance is dependent on the wavelength of the
incoming radiation; since radio waves have such large wavelengths, the
telescopes can be 10s, 100s, or even 1000s of miles apart |
9 |
|
106.
|
What is the Very Large Array (VLA)? Discuss some
stats and its location. |
the VLA is a grouping of 27
movable radio telescopes that are all linked together; they are arranged
in a Y formation on railway tracks in Socorro, New Mexico; each dish is
82 feet in diameter and they can be moved up to 22 miles apart |
9 |
|
107.
|
What is the VLBA and what makes it so special? |
the Very Long Baseline Array
is a grouping of 10 radio telescopes, each measuring 82 feet across;
these telescopes are located across one side of the earth from the
Virgin Islands to New Hampshire to Hawaii; working together, these
telescopes equal a single telescope with a diameter roughly equal to the
diameter of earth |
9 |
|
108.
|
How are redshifts and blueshifts seen in radio
astronomy? |
astronomers see these
spectral lines as low and high points in a graph of wavelength; low
points represent wavelengths absorbed by celestial objects and high
points represent wavelengths emitted by strong radio sources |
9-10 |
|
109.
|
What has analysis of red- and blueshifts revealed
about the Milky Way? |
it has revealed how rapidly
the galaxy rotates and how the speed of stars changes with their
distance from the galactic center; after some math, it has also been
concluded that the mass in the galaxy is about 1 trillion times the mass
of the sun |
10 |
|
110.
|
What is gravitational lensing? |
it is when radiation from a
small, distant galaxy passes by a massive galaxy that is between the
distant galaxy and the earth; the gravitational pull of the massive
galaxy bends the radiation just like an optical lens would in a visible
light telescope; gravitational lensing can produce an image of the small
galaxy in the shape of an arc or even a ring and astronomers can study
radiation in the arc or ring to learn about the galaxy |
10 |
|
111.
|
What is the range of wavelengths in the ultraviolet
spectrum? |
400 nm to about 10 nm |
10 |
|
112.
|
What ultraviolet range can be detected at the
earth’s surface? |
400-300 nm (near ultraviolet) |
10 |
|
113.
|
What types of ultraviolet are the most useful to
astronomers and what are their wavelength ranges? |
far ultraviolet: 300-100 nm
extreme ultraviolet: 100-10
nm |
10 |
|
114.
|
Discuss the International Ultraviolet Explorer.
When was it active and what did it study? |
active from 1987-1997; it
studied wavelengths from 320-115 nm |
10 |
|
115.
|
Discuss the Extreme Ultraviolet Explorer. Who did
it belong to, when was it active, and what did it do? |
it belonged to NASA, was
active 1992-2001, and studied wavelengths from 76-7 nm |
10 |
|
116.
|
Discuss the Far Ultraviolet Explorer. Who did it
belong to, when was it active, and what did it do? |
belonged to NASA, active
starting in 1999, and it’s studying wavelengths from 120-90 nm |
10 |
|
117.
|
What is the largest and most sensitive ultraviolet
telescope? What do astronomers use it to study? |
the Hubble Space Telescope;
they use it to study hydrogen gas whose strongest spectral lines are in
the UV spectrum |
10 |
|
118.
|
What is deuterium, when did it form, and why is it
significant? |
deuterium is a heavy form of
hydrogen; it all formed in the first 1000 seconds after the Big Bang;
the amount of deuterium formed is related to the present amount of
matter in the universe; knowing the current amount of deuterium informs
astronomers as to how dense the universe is |
10 |
|
119.
|
What is SOHO, what does it monitor, what devices
does it use, and when was it launched? |
SOHO is the Solar and
Heliospheric Observatory; the European Space Agency launched it in 1995;
it monitors the sun with visible light and UV cameras and spectrographs |
10 |
|
120.
|
What does SOHO produce? |
highly detailed images of the
sun in the UV light of helium gas (60,000 degrees C) or iron gas
(1,500,000 degrees C) |
10 |
|
121.
|
What is TRACE? |
Transition Region and Coronal
Explorer; NASA’s version of SOHO |
10 |
|
122.
|
What is the wavelength range of x-rays? |
10 nm to about .1 nm |
10 |
|
123.
|
What kinds of regions in space produce x-rays?
Give some examples. |
the hottest regions in space
like the sun’s corona, disks of material around black holes, hot gas at
the center of clusters of galaxies, and quasars |
10 |
|
124.
|
What happens to material near black holes? |
it spins around and around as
the black hole sucks it in; while it does that the material rubs
together causing friction, thereby heating up and emitting x-rays |
10 |
|
125.
|
Why is it difficult to study x-rays? |
they do not penetrate the
earth’s atmosphere; they also pass through ordinary telescope lenses and
mirrors; telescopes with special mirrors allowing x-rays to hit off them
at low angles can be used however |
10 |
|
126.
|
What do some x-ray telescopes use instead of
mirrors? |
they have iron slats and the
space between the slat allow the rays to enter the telescope and hit
special detectors |
10 |
|
127.
|
Discuss the High –Energy Astronomy
Observatories—important dates, what they studied, etc. |
in the 1970s and 1980s a
series of High-Energy Astronomy Observatories mapped the sky in x-rays
and closely observed some celestial objects |
10 |
|
128.
|
Discuss Rosat—important dates, what it studied,
etc. |
in operation from 1990-1998,
Rosat was a German-US-British spacecraft that surveyed the sky in x-rays |
10 |
|
129.
|
Discuss the Rossi X-Ray Timing Explorer—important
dates, who it belongs to, etc. |
NASA launched Rossi in 1995 |
10 |
|
130.
|
Discuss Yohkoh—who it belongs to, what it studied,
etc. |
Yohkoh is a Japanese
satellite that sends back images of the sun showing the corona and solar
flares |
10 |
|
131.
|
Discuss the Chandra X-ray Observatory. |
in July 1999, NASA launched
Chandra from the space shuttle Columbia; it produces the most detailed
x-ray images |
10 |
|
132.
|
Discuss the XMM-Newton. |
in December 1999, the
European Space Agency launched XMM-Newton from a Araine 5 rocket; its
telescopes can detect fainter x-rays than Chandra, but with a lower
resolution; the XMM-Newton mostly investigates the spectra of x-ray
sources |
10 |
|
133.
|
What wavelength range do gamma rays have? |
.1 nm and less |
10 |
|
134.
|
What is so special about gamma ray photons? |
they have the highest energy
in the electromagnetic spectrum |
10 |
|
135.
|
What are solar flares? |
explosive events on the sun
that reach millions of degrees |
10 |
|
136.
|
How are gamma rays created? |
when particles of matter and
antimatter annihilate each other, gamma rays are produced |
11 |
|
137.
|
What is “antimatter”? |
antimatter is made up of
antiparticles; these are particles that have the same mass as a
corresponding particle but with opposite charge |
11 |
|
138.
|
Where are some places where gamma rays are created? |
center of the Milky Way, Crab
Nebula in the constellation Taurus, Geminga (a nearby collapsed star) |
11 |
|
139.
|
What does the Crab Nebula consist of? |
matter thrown out during a
supernova observed in 1054 AD |
11 |
|
140.
|
When was the Compton Gamma Ray Observatory in orbit
and what is one thing it regularly detected? |
1991-2000; following up on a
previous discovery that gamma ray bursts come at random intervals from
various places in the sky, it detected one gamma ray burst approximately
every day |
11 |
|
141.
|
What is HETE-2? |
High Energy Transient
Explorer 2 is a satellite launched in 2000 by an multinational team |
11 |
|
142.
|
What does HETE-2 do? |
it detects the location of
gamma ray bursts in the sky; then it sends that information down to MIT
and they relay that info to ground-based observers all over the world
who then study that location with optical telescopes |
11 |
|
143.
|
What did HETE-2 sense in March 2003? |
a 25 second gamma ray burst
coming in the direction of Leo; ground astronomers concluded it came
from a supernova 2 billion light-years from earth |
11 |
|
144.
|
What gamma ray explorer went into orbit in October
2002? |
the European Space Agency’s
Integral (International Gamma Ray Astrophysics
Laboratory) |
11 |
|
145.
|
What does the gamma ray explorer that went into
orbit in Oct. 2002 observe? |
it studies black holes,
neutron stars, centers of certain galaxies, and supernovae |
11 |
|
146.
|
What’s so unusual about Integral’s orbit? |
it orbits between 5,600 and
96,000 miles from the surface of the earth to spend most of its time
above the Van Allen belts to reduce radiation interference |
11 |
|
147.
|
Who participated in getting Integral “off the
ground?” |
Russia launched it from
Kazakhstan; US, Czech Republic, and Poland also were involved
(presumably in its development) |
11 |
|
148.
|
What is a neutron star? |
a collapsed star without
enough mass to become a black hole |
11 |
|
149.
|
What is a neutrino? |
a tiny particle from space;
they rarely interact with particles on earth |
11 |
|
150.
|
What is Super-Kamiokande and what does it do? |
it is a deep underground mine
in Japan; it went into operation in 1996; the main part of it is a
cylindrical tank that is 131 ft. deep and 131 ft. in diameter (40 m);
detectors sense when a neutrino collides with a nucleus or electron in
the water |
11 |
|
151.
|
What is SNO? |
Sudbury Neutrino Observatory
in Greater Sudbury, Ontario; uses 1000 tons of heavy water (H20 w/ H
having a nucleus with one proton and a neutron); its operation began in
1999 |
11 |
|
152.
|
What are the 3 kinds of neutrinos? |
muon-, tau-, and
electron-neutrinos |
11 |
|
153.
|
What kind of neutrinos were found to be “missing”
in the early 1960s? What made them “missing,” why are they missing, and
who confirmed this theory? |
electron-neutrinos (from
nuclear reactions in the sun); only ½-1/3 electron-neutrinos as were
expected were found; probably they turned into muon- and tau-neutrinos
as they traveled from the sun to the earth; in 2001 Sudbury confirmed
this with measurements compared between SNO and Super-Kamiokande |
11 |
|
154.
|
What are cosmic rays? |
electrically charged,
high-energy particles |
11 |
|
155.
|
Name the two kinds of cosmic rays and how they
differ. |
primary cosmic rays
(primaries) originate from outer space; secondary cosmic rays (secondaries)
form in the earth’s atmosphere |
11 |
|
156.
|
How does the second kind of cosmic rays form? |
when primaries collide with
atoms at the top of the atmosphere, secondaries are formed |
11 |
|
157.
|
What are of the first kind of cosmic rays made of
and how do scientists detect them? |
primaries are mostly made up
of protons or other nuclei of atoms which usually cannot penetrate the
earth’s atmosphere; instruments aboard high-flying airplanes or
satellites detect them |
11 |
|
158.
|
Where can the second type of cosmic rays be found? |
within the earth’s
atmosphere, often at low altitudes; special sensors can even detect the
few that hit the earth’s surface |
11 |
|
159.
|
Where do most cosmic rays come from? |
some come from the sun, but
most are galatic cosmic rays that originate outside the solar system |
11 |
|
160.
|
How do cosmic rays acquire their tremendous energy? |
we don’t know, but some
scientists theorize that the energy comes from supernova explosions |
11 |
|
161.
|
What type of radiation are scientists unable yet to
detect? |
gravitational waves |
11 |
|
162.
|
Who discovered this type of radiation, when, and
what was the name of his theory? |
Albert Einstein, 1915, he
predicted these waves in his general theory of relativity |
11 |
|
163.
|
What indirect evidence as been found to suggest
this kind of radiation actually exists? |
certain variations in the
orbits of two dense stars that revolve about each other |
11 |
|
164.
|
What is direct sampling? |
examination of piece of
material from celestial objects |
11 |
|
165.
|
What is the most common kind of material from outer
space and where did it originate? |
meteorites (rocks that fell
through the atmosphere from other parts of our solar system); most come
from asteroids, and a few from Mars or our moon |
12 |
|
166.
|
Where is the best place to find meteorites on earth
and why? |
Antarctica because the rocks
show up better on the polar ice than they do among other terrain |
12 |
|
167.
|
What material was brought back by astronauts
between 1969 and 1972? |
moon rocks |
12 |
|
168.
|
What did the Soviet Union’s Luna 16 spacecraft
collect and when? |
moon soil in 1970 |
12 |
|
169.
|
What have scientists concluded about bits of space
dust collected off of high-altitude aircraft? |
some of the dust came from
beyond our solar system |
12 |
|
170.
|
What is scientific modeling and what are they used
for in astronomy? |
sets of mathematical
equations; used to represent certain processes, like the formation of a
star |
12 |
|
171.
|
What is computer modeling (scientific modeling)
important in astronomy? |
some of the processes the
models allow scientists to see happen too slowly to observe in the
natural universe; others occur in inaccessible places (such as the
interiors of stars) |
12 |
|
172.
|
Where is the American Association of Variable Star
Observers and how to amateur astronomers help the association? |
Cambridge, Massachusetts;
they send in observations from around the world and the association can
then compile the observations for professional astronomers who want to
know what certain stars are doing before conducting observations of
their own |
12 |
|
173.
|
What astronomical observatory was built in England
more than 4,000 years ago? How was it used? |
Stonehenge; certain stones
and alignments of stones appear to mark locations of astronomical
importance (e.g., where the sun rises on the longest day of the year);
it was also probably used as a place of worship |
12 |
|
174.
|
How do European constellations differ from Chinese
constellations? |
the patterns found and mapped
differ |
|
|
175.
|
How old (probably) are Chinese constellation maps? |
about 4,000 years (2000 BC) |
12 |
|
176.
|
What civilization first noted patterns in the star
formations in our sky that lead to the constellations we study today?
When? |
the Sumerians in 2000 BC |
12 |
|
177.
|
By when were the Babylonians noting the position of
the moon and planets? |
700 BC |
12 |
|
178.
|
Aside from planetary movement, what other
astronomical occurrences did Babylonians observe and record? |
eclipses |
12 |
|
179.
|
When did Aristotle develop his system of physics
and astronomy? |
300s BC |
12 |
|
180.
|
About how long did Aristotle’s system of astronomy
survive? |
about 2000 years |
12 |
|
181.
|
When did Ptolemy modify Aristotle’s system to
account for retrograde motion? |
100s AD |
12 |
|
182.
|
|
|
|
|
183.
|
The altitude of the celestial pole corresponds to
what of the earth observer’s? |
the observer’s latitude |
14 |
|
184.
|
What is the zenith? |
the point directly above the
observer on the celestial sphere |
14 |
|
185.
|
What is the celestial meridian? |
an imaginary line that passes
from the celestial north pole through the zenith to the southern pole |
14 |
|
186.
|
What is the zodiac? |
a region of 12 constellations
in the sky through which the sun, the moon, and 5 visible planets move |
14-15 |
|
187.
|
What is the sun’s path through the celestial sphere
called? |
the ecliptic |
15 |
|
188.
|
What shape does the sun’s path take in the
celestial sphere and relative to what? |
it takes an S shape relative
to/“around” the celestial equator |
15 |
|
189.
|
By how much (approximately) is the earth’s axis
tilted? |
23.5 degrees |
16 |
|
190.
|
What phenomenon causes the dates of the Summer and
Winter Solstices to not stay the same? |
precession |
16 |
|
191.
|
What is precession? |
the celestial north pole
moving in a coning motion due to the earth’s tilt and the gravitational
pull of the sun and moon on the earth |
16 |
|
192.
|
How quickly does precession occur? |
very slowly; it will take
26,000 years for the celestial north pole to complete a coning cycle |
16 |
|
193.
|
When and who noted the change caused by precession? |
Hipparchus, 2000 years ago |
16 |
|
194.
|
Explain why circumpolar objects (some) pass through
the meridian twice. |
Due to the revolution of the
earth around the sun, the sun (a near object) moves each day in the
earth’s sky; our 24 hour day accounts for this in that it takes 24 hours
for the sun to start at your meridian and then to pass through that
meridian again.
However, farther objects
(like stars) pretty much stay put, so, for instance, if a star is just
to the left of the sun on one day, the star will pass through the
meridian about the same time as the sun does, but the next day (because
the sun has moved over) the star will pass through the meridian before
the 24 hours is up and the sun hits the meridian again. |
see Crone; ref. on
16 |
|
195.
|
What is astrometry? |
the study of the movement of
the stars through the backdrop of other stars |
16 |
|
196.
|
What are the three types of stellar motion? |
astrometry, diurnal motion,
and the third may not be considered “stellar motion” but it has to do
with the fact that the sun is constantly changing position and therefore
making some stars visible and some invisible in our night sky over
months at a time |
16 |
|
197.
|
What are circumpolar stars? |
stars that circle around the
celestial poles and are therefore (almost) always visible in the sky
because they do not disappear below the horizon |
16 |
|
198.
|
How did ancient people use the third kind of
stellar motion? |
they would plan migrations or
the planting of crops based on when certain stars became visible in the
early morning sky |
16 |
|
199.
|
What is binary motion? |
the motion of two stars as
they orbit a common center; this is part of what makes up astrometry |
16 |
|
200.
|
What accounts for astrometry? |
binary motion (the motion of
two stars as they orbit a common center) and the actual motion of stars
as they orbit the center of the galaxy at different speeds |
16 |
|
201.
|
How does star movement affect constellations? |
the movement of stars can
cause change in constellation shapes, but because this takes so long
it’s too slow to see without careful measurements over long periods of
time |
16 |
|
202.
|
What is diurnal motion? |
the movement (due to the
earth spinning on its axis) of the stars as they pass over the evening
sky |
16 |
|
203.
|
How do stars move when you look for an extended
period of time toward the north? |
they move in circles around
the celestial north pole |
16 |
|
204.
|
How do stars (not near the celestial poles) move in
the night sky? |
they rise in the east and set
in the west |
16 |
|
205.
|
How does the movement of planets differ from the
movement of stars? |
the planets change positions
(over the course of a few nights) relative to the stars in the sky |
16 |
|
206.
|
Where does the word “planet” come from and what
does it mean? |
it comes from Greek; means
“wanderer” |
16 |
|
207.
|
What is a planet’s usual motion called and which
way does it move? |
it’s called prograde motion
(or direct motion); it moves through the stars toward the east |
16 |
|
208.
|
What is planetary “backward” motion called and
which way do the planets move when they are going “backward?” |
retrograde motion; they move
west through the stars |
16 |
|
209.
|
What is retrograde motion partly responsible for
when it come to solar theories offered hundreds of years ago? |
it is one of the reasons
geocentric solar system theories failed; these theories could not
correctly account for retrograde motion |
16 |
|
210.
|
Whose system, prior to Copernicus, came closest to
explaining retrograde motion? |
Hipparchus’s, and this system
was refined by Claudius Ptolemy and is often referred to as the
Ptolemaic system |
16 |
|
211.
|
What was the problem with the theory about
epicycles and deferents? |
Ptolemy system could never
predict the position of the planets exactly |
16 |
|
212.
|
Describe the path in the sky that Mars takes when
it goes in direct motion to retrograde motion back to direct motion. |
it makes a zig-zag, and at
each point before Mars changes direction, the planet seems to slow down |
16 |
|
213.
|
Whose theory correctly explained retrograde motion
and why does it explain it? |
Copernicus; his theory stated
that all the planets, including earth, were moving in orbits around the
sun. The different orbits of the planets (and the time in which it took
them to make their orbits) accounts for retrograde motion |
16 |
|
214.
|
What determines the phases of the moon? |
the alignment of the sun,
earth, and moon |
17 |
|
215.
|
Describe what happens to cause a new moon. |
the moon is aligned between
the earth and the sun causing the illuminated side to be facing away
from earth and the observer on earth cannot see the moon |
17 |
|
216.
|
Does the moon only come out at night? |
um, no, but it can only be
seen at night most of the time because the light reflected from it is
often drowned out by the powerful light of the sun |
17 |
|
217.
|
Describe what happens to cause a new moon. |
in that case the illuminated
face of the moon is fully facing the earth; it isn’t so much that the
earth is between the sun and the moon (because that would cause an
eclipse) but that the moon is positioned on the side of the earth
farthest from the sun (but not necessarily directly behind the earth
compared to the sun) |
17 |
|
218.
|
What causes an eclipse to happen? |
like lunar phases, eclipses
depend upon the alignment of the earth, moon, and sun |
17 |
|
219.
|
What phase must the moon be in for a lunar eclipse
to occur? |
full moon |
17 |
|
220.
|
What causes the lunar eclipse? |
in this case, the moon is
positioned directly in line with the earth and the sun with the earth in
the middle; the shadow of the earth passes over the moon, thereby
darkening it |
17 |
|
221.
|
What is the line of nodes? |
it is the line at which the
orbital plane of the earth and the orbital plane of the moon cross |
18 |
|
222.
|
Why is the line of nodes important when talking
about eclipses? |
for any eclipse to occur, the
moon must be at or near the line of nodes |
18 |
|
223.
|
Why are eclipses so rare? |
because two factors need to
occur for an eclipse to take place: 1) the moon must be at or near the
line of nodes, and 2) the moon must be in the correct phase |
18 |