Animations about Thermal (Blackbody) Radiation
Concept Map about Earth's Atmosphere
Concept Map about Venus' Atmosphere
Thought Questions from first Midterm
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Light Atoms Planet Atmospheres |
Thermal (Blackbody) Radiation The Sun Jovian Planets |
Types of Spectrum Formation of the Solar System Terrestial Planet Geology |
Which of the following models can explain what a red filter does to light?
If the light hitting the prism goes through a red filter first, what will you end up seeing on the screen?
What is the meaning of the pictured experiment?

A person's clothes appear dark blue when the fluorescent lights (white light) are on. How will the person's clothes appear when the street lamp (which emits pure yellow light) is on?
A person's clothes appear dark red when the fluorescent lights (white light) are on. How will the person's clothes appear when the street lamp (which emits pure yellow light) is on?
If you look at a blue dot on the screen through a red filter, what will you see?
If you look at a red dot on the screen through a blue filter, what will you see?
Compared to other colors of visible light, red light has
The number line below has values increasing toward the right. Which quantities could this number line represent?
If you removed the green and orange light coming from an object that
is releasing the mixture below, what would the spectrum look like?
Answer: A. Hint: Green and orange are kinds of light on their
own.
Which of the following spectrums represents the light from red and
blue TV dots?
Answer: D. Hint: A red dot on your TV screen don't exclusively
release red light, but it does mostly release light near red in
wavelength.
Which of the following is true?
At a particular temperature, the light bulb appears orangish in color if you
look at it with only your eye. What color has to be added in large
amounts to get it to appear whiter?
As I increase the temperature of the light bulb filament, one student
watches the color blue in the rainbow, while another student
watches the color red. What will the two students see?
Which color will become visible last as the temperature of the light bulb
filament is increased?
Police are following a suspect at night in San Diego using an infrared
camera. If the suspect jumps into the harbor, what will be seen on the
camera?
Earth and human beings both emit thermal radiation. Earth's average
temperature is similar to that of a human being. What kind of light
does Earth emit the most of? (Ignore what Earth reflects.)
Answer: 4. Hint: Stars in general release something close to a
continuous spectrum -- not just one color. Because it appears red, it must
be releasing mostly light at the red end of the rainbow.
I have a jug of clear blue liquid. Which of the following is true?
When I pass the jug of clear blue liquid in front of the light bulb,
what will you see in the spectrum?
Which kind of spectrum would you see if you were looking in the
direction shown by the arrow?
Which kind of spectrum would you see if you were looking in the
direction shown by the arrow?
Which kind of spectrum would you see if you were looking in the
direction shown by the arrow?
Which of the pictures below shows Earth correctly scaled in comparison
to the Sun?
Answer: C. Hint: All of the planets go around the Sun for a
reason --- it has hundreds of thousands times more mass than the Earth does!
If you added together all of the planets, how would their mass compare
to the mass of the Sun?
If your daring professor sits in the ``CHAIR OF DEATH'' with his arms
outstretched and starts himself rotating, what will happen if he
pulls his arms in toward his body?
What will happen if he moves his arms up and down, parallel to his
spin axis?
What would happen to a cloud that collapsed without any rotation at
all?
What kind of material would you expect to be able to condense out
of the gas closest to the Sun?
The dense terrestrial planets tend to be located nearer the Sun because
Which of the following statements describes the meaning of
condensation?
Which of the following pairs of planets formed at temperatures below
the freezing point of water?
Would it have been possible for a large Jupiter-like planet to form in
the location of Mars?
Imagine the young solar system has a disk of orbiting dirt and ice
particles. As time went on, particles collided and stuck together to
make larger objects. As a result, new collisions started happening
Which of these facts is NOT explained by nebular theory?
What kinds of liquid or solid materials could be present far from the Sun
when the solar system was forming?
What happens to the crust where extension occurs?
Where are most of the volcanoes on Earth that have been mapped?
Imagine an impact occurred on the continental plate millions and
millions of years ago, leaving a crater near the base
of the volcano. Why would there be little evidence of this crater
found today?
In the image below, how heavily covered with craters is Mars?
Is there a relationship between the number of craters and either the
distance of the planet from the Sun or the size of the planet?
Imagine the pictures below were taken of an area of the Moon with craters at
various times in the past. What is the correct order of the pictures from
past to present?
The dark grey area is one of the Moon's maria. How old is the
lava in it compared to the other craters?
Rocks that were collected in the Moon's "maria" during the Apollo
missions have been radioactively dated. Using the information in the
graph, this tells us that most of the craters were made...
Answer: 2. Hint: The maria have very few craters, but the ages
of the rocks are generally more than 3 billion years old.
In the picture of Mars' surface below, which is older?
In the picture of Mars' surface below, "A" is the set of gullies, "B"
is the crater and splashed rock on the right side, and "C" is the
crater at the top. What is the order from oldest to youngest?
In the picture of Venus' surface below, "1" is the set of long cracks
(from tectonics), and "2" and "3" are lava domes. What is the order
from oldest to youngest?
Is there a relationship between the number of volcanoes and either a
planet's i) distance from the Sun or ii) its size?
Suppose a terrestrial planet the same age as Earth is discovered
orbiting another star, and it is your job to predict what it
is like. If the planet is known to have mass and size smaller than
Venus, but more than Mars, what would be the best prediction based on
our understanding of the solar system?
When a certain rock solidified, it contained 4% chemical X. Chemical X
radioactively decays to form chemical Y and has a half-life of 80
million years. If the rock now has 1% chemical X, how old is the
rock?
The choices below describe 4 hypothetical planets. Which one's
surface would you expect to be most crowded with impact craters?
(Assume they orbit a star just like the Sun and are the same age as
the planets in our solar system.)
Answer: 2. The smallest planets are
geologically dead, and haven't been able to clean up most of the
craters that were left very early in the solar system's history.
What would a large terrestrial planet be like today if it was far from the Sun?
The temperature of the parts of Jupiter's atmosphere that we can see
from space is around -200 degrees F. What would we see if we look at
the visible light portion of Jupiter's spectrum?
Which of the following kinds of light from the Sun gets through
Earth's atmosphere most easily and reaches the surface?
What gas in Earth's atmosphere is suspected of causing global warming?
What does carbon dioxide gas do in Earth's atmosphere?
The arrows in the diagrams below represent the rate of heat flowing
into and out of a greenhouse. In which case will the greenhouse heat
up?
Answer: B. Hint: More heat is flowing into the greenhouse than
is coming out, and with the increased amount of heat inside, the
temperature will go up.
What would Earth's temperature be like if Earth reflected more of the
sunlight hitting it?
In the flowchart below, where are the best places to put the following:
A. NO CONDENSATION, B. MANY VOLCANOES, C. GREENHOUSE EFFECT, D. GRAVITY.
Answer: 1. B, 2. D, 3. A, 4. C Hint: The mass of the planet
influences the number of volcanoes present, and the gravity at the
surface. High temperature means that gases like water can't condense,
and the thick atmosphere leads to a greenhouse effect that increases
the temperature more.
In the flowchart below, where are the best places to put the following:
A. CONDENSATION, B. FEW VOLCANOES, C. GAS LOSS TO SPACE, D. WEAK GRAVITY.
Answer: 1. D, 2. C, 3. A, 4. B Hint: The mass of the planet
influences the number of volcanoes present, and the gravity at the
surface. Low temperature means that gases like water can condense.
Jupiter's Great Red Spot is a deep red color. Which of the following
could be a reason for this?
Below is a picture of Saturn's moon Enceladus. Which of the following
statements about its surface is probably true?
What happens to cans of diet tea and energy drink when put in water?
A planet discovered orbiting another star was found to have a mass
that is 0.6 times Jupiter's mass, and a diameter that is 1.44 times
Jupiter's size (so that its volume is 3 times greater than
Jupiter's). This planet has a density that is...
What should happen to a rapidly spinning planet it it is mostly made
of materials that aren't solid?
If the Sun was a cooler star, what kind of light would be most intense?
J. P. Adams, D. J. Loranz, E. E. Prather, and
T. F. Slater. Lecture Tutorials for Introductory Astronomy --
Instructor's Guide, 2002 (Prentice Hall).
Answer: 1. Hint: Frequency and energy increase the other
direction, and speed is the same for all kinds of light.
Answer: 4. Hint: How do energy, wavelength, and frequency
relate to each other?
Thermal (Blackbody) Radiation
If you watch a light bulb with your eyes alone, what is going to
happen to the light bulb filament as I increase its temperature?
Answer: 1. Hint: The light bulb filament is a blackbody.
As the temperature increases, both the color and brightness of the
filament change. REMEMBER: "red hot" is NOT hotter than "white
hot"!!!
Answer: 3. Hint: "White light" is a roughly equal mixture of
all of the colors of the rainbow. If the filament appears orange,
there is more red, orange, and yellow than there is green and blue.
Answer: 1. Hint: Photons of light are released during every
collision between atoms in the filament. The higher the temperature,
the more collisions occur. Every collision results in a release of light.
Answer: 6. Hint: As the temperature increases, collisions
become more violent (and more energetic) because the atoms are
travelling faster. Photons with a lot of energy can only be created
during the violent collisions.
Answer: 4. Hint: Normally humans release a lot of infrared light
because of their temperatures. When the suspect jumps in the cold San Diego
water, his skin immediately cools off and makes him "dim".
Answer: 3. Hint: Humans relase infrared light (remember infrared cameras?), and so does Earth. Their temepratures are much lower than stars, and so they release "redder" light.
Types of Spectrum
Which of the following graphs probably represents the spectrum of
Betelgeuse best? (Betelgeuse is a star that looks red to the eye.)
Answer: 2. Hint: The jug is not hot, so it is not emitting
visible light. The fact that you see it is blue means that blue light
(and similar colors) is reaching your eyes.
Answer: 4. Hint: The jug is not hot, so it is not emitting
visible light. It is transparent. The fact that you see it is blue
means that blue light is reaching your eyes. So in this case, some of
the orange and yellow light is likely to be removed from the mixture
of light coming from the light bulb.
Answer: 2. Hint: A light bulb releases a continuous spectrum of
colors, but chemicals in the gas in front of it will absorb some of
the light having specific colors.
Answer: 1. Hint: A light bulb releases a continuous spectrum of
colors.
Answer: 3. Hint: Chemicals in a hot gas will release light
having specific colors. The colors depend on which chemicals there
are.
Atoms
Formation of the Solar System
If you flipped a coin to decide which direction each of the 8 planets
went around the Sun, what is the probability that all of them would
end up going around in the same direction?
Answer: 5. Hint: With a 1/2 probability of getting heads each flip,
the chances of getting 8 heads is 1 in 256. (If it is OK to get all tails OR all heads, then the chances are 1 in 128.)
Answer: 1. Hint: The Sun contains almost all of the mass in the
solar system - the planets go around the Sun for a reason....
Answer: 3. Hint: If you have ever watched ice skaters, this
should be easy.
Answer: 2. Hint: A little harder, but again it comes from watching
ice skaters.
Answer: 1. Hint: With rotation, the collapsing gas can start to
orbit the Sun once it starts moving fast enough (like an ice skater pulling
in her arms).
Answer: 3. Hint: Which of the substances above melts at the highest
temperature? Rocky materials are a close second.
Answer: 3. Hint: The density of a planet does not affect how
strong the gravity is - remember that gravity depends on mass. Rock
and metal was the only solid raw material available for the
terrestrial planets because of the high temperature.
Answer: 4. Hint: When water condenses on your soda
bottle, what is happening?
Answer: 5. Hint: Jupiter and Saturn got so big because they had
more raw material to start with --- namely, hydrogen compounds like water
that could condense into icy material.
Answer: 2. Hint: Was the temperature at the location of Mars
hotter or colder than the freezing point of water in the early solar
system?
Answer: 3. Hint: As the planetesimals collide and stick, there
are fewer objects left to collide. It gets harder for them to bump
into each other because there will also be more space between the ones
that are left. This ends up being more important than the larger
masses of the objects that are left because the force of gravity
decreases so strongly as distance increases.
Answer: 4. Hint: The number of planets depends on chance ---
there could have been more or less depending on how many collisions
there were during the formation of the solar system.
Answer: 4. Hint: The temperature is low enough for BOTH
rocky/metallic "dirt" and "icy" snowflakes to condense (just barely low
enough for snowflakes, but much lower than is necessary for dirt to
condense), but it is NEVER cold enough for light gases like hydrogen and
helium to condense.
Terrestrial Planet Geology
Mountain ranges form where plates are
Answer: 1. Hint: When the plates run into each other, one plate
"crumples" and forms mountains as the other plate slides under.
Answer: 3. Hint: In this case, the crust is stretched out, and
when it "tears" it forms cracks and valleys.
Answer: 5. Hint: This is the "Ring of Fire" --- most volcanoes on Earth
are found at the edges of plates.
Answer: 3. Hint: Volcanoes sit on continental plates that
don't get melted during plate tectonics, but they do put out a
lot of lava...
Answer: 3. Hint: This is mostly a test of your skills at
observing. The northern hemisphere of Mars has very few craters
compared to the southern hemisphere - possibly because there was once
an ocean in the north.
Answer: 4. Hint: This may not seem to make sense, but the
larger planets definitely have fewer craters. Some reasons: their atmospheres
help melt smaller space rocks before they hit the surface, water erosion can
erase some craters, and volcanic activity or tectonics
can cover them up or completely destroy them.
Answer: 4. Hint: Craters that overlap help: the one on the
"bottom" must have been there the longest. The total number of craters
also helps: more creaters means that it has been longer since something
has "cleaned" the surface.
Answer: 3. Hint: Again, the idea of "overlapping" helps tell
which feature was laid down most recently.
In the picture of Mars' surface below, there are several overlapping
features. ``A'' is a volcano, ``B'' and ``C'' are craters, and ``D''
is the surface of the flat plain that surrounds everything. Keeping in
mind that the surface of the plain might have been covered up by
lava from another volcano, which is the correct order of their ages
(from oldest to youngest)?
Answer: 5. Hint: Look carefully at what overlaps what. Volcano
"A" must be oldest because everything overlaps it. Crater "C" has
obliterated part of "A" put has been filled in by the lava flow that
formed the plain "D". "D" has covered over the lower parts of "A".
The crater "B" overlaps both the "A" and "D", so it must be youngest.

Answer: 1. Hint: It appears as if some runoff water broke
through the side of the crater, and left some mud on the floor of the
crater.
Answer: 5. Hint: The crater at top is overwritten by gullies, and the crater at the side has covered up some of the gullies.
Answer: 3. Hint: Look at how the two lava domes over lap each
other, and how the cracks cut through the domes.
Answer: 3. Hint: Smaller planets cool off faster because they
don't insulate themselves well. The example I used in class was
comparing a cooked meatball and a cooked turkey. The inside of a
turkey can stay hot hours after it has been taken out of the
oven. (Note: Venus is slightly smaller than Earth and has a somewhat
larger number of volcanoes, but the differences are not that big.)
Answer: 2. Hint: Mars has dormant volcanoes. Venus has a fairly
large number of active ones (astronomers think). Without knowing
exactly how massive this new planet is, we won't be able to predict
with any confidence whether the volcanoes are active or not.
Answer: 5. Hint: Only one fourth of the original chemical X is
left, so the rock must have gone through two half-lifes (one half
decays in the first half-life, and half of the remaining chemical X
decays in the second half-life).
Size
Distance from Sun
1. same as Venus
same as Mars
2. same as Moon
same as Mars
3. same as Mars
same as Earth
4. twice Earth size
same as Mercury
Answer: 2. The large size of the planet means it kept hot inside, and
would probably have many active volcanoes today. This would probably
mean few visible craters since they would have been covered up. If the
planet is far from the Sun, the low temperature on its surface
would mean erosion wouldn't be too important --- water would have frozen.
Planet Atmospheres
When light from the Sun passes through the gas in a planet's atmosphere,
what happens?
Answer: 1. Hint: Some of the light passing through the
atmosphere gets absorbed. See earlier thought questions on light.
Answer: 3. Hint: The planet is colder than a person, so it
can't be emitting visible light. It can absorb some of the Sun's light,
while it reflects the rest.
Answer: 2. Hint: Human eyes developed to make use of an
abundant kind of sunlight that makes it through the atmosphere...
Answer: 3. Hint: Carbon dioxide is the only gas in the
atmosphere of Venus, and look what happened with it...
Answer: 2. Hint: It is important to realize the difference
between what ozone does and what carbon dioxide does (like answer
#3).
Answer: 2. Hint: Less energy would get absorbed by Earth, so
that it wouldn't warm up as much. This partly why people worry about
the melting of the polar ice caps with respect to global warming.

Jovian Planets
Neptune is a deep blue color. Which of the following could be a reason
for this?
Answer: 4. Hint: Neptune is too cold to release any visible light -
what we see is reflected sunlight, which is white. So, for it to appear blue,
it has to remove the red light from the mix of light.
Answer: 3. Hint: Jupiter is too cold to release any visible
light - what we see is reflected sunlight. A normal sunlight mixture
is white. For the reflected light to appear red, it has to remove the
blue light from the mix of light.
Answer: 3. Hint: Notice the lack of craters in the lower left.
Answer: 1. Hint: Most of the time energy drinks will sink
because they are packed full of sugar, and this makes them denser than
water on average, and makes them sink. Diet drinks use more
concentrated chemical sweeteners that don't make the liquid
significantly more dense than water.
Answer: 1. Hint: The planet has less mass than Jupiter, and it
is spread out over a larger volume, so that its average density must
be less than Jupiter's. This makes its average density even less like
a terrestrial planet (which has higher density). Average density is
total mass divided by volume.
Answer: 1. Hint: A good analogy is to think about what happens
to pizza dough when it is spun. The dough can stretch, and it will
stretch into a disk when spun fast.
The Sun
If the Sun is about 10 times the width of Jupiter and both are spheres,
roughly how does the Sun's volume compare to Jupiter's?
Answer: 4. Hint: If you think of a cube instead of a sphere,
realize that the cube would be 10 times wider, longer, and
taller. The volume of a cube is length times width times height.
Answer: 1. Hint: Cooler means longer wavelength for the most intense color.
Some of the questions above are taken from the following
sources:
Last update: March 20, 2013