Astronomy 101 Thought Questions - Fall 2014

Thought Questions for Astronomy 101 (Fall 2014)
Instructor: Eric Sandquist


Animations about Color

Animations about Thermal (Blackbody) Radiation

Concept Map about Earth's Atmosphere

Concept Map about Venus' Atmosphere

Thought Questions from first Midterm


Thought Questions for Midterm #2:

Question Topics:

Light
Atoms
Terrestial Planet Geology
Parallax
Thermal (Blackbody) Radiation
The Sun
Planet Atmospheres
Star Luminosity
Types of Spectrum
Formation of the Solar System
Jovian Planets

Light

Suppose you put light through a prism, and all of the colors of the rainbow project to the front of class. If a red filter is put into the beam, what happens to the projected rainbow?

  1. You see mostly red light; the blue and green disappear.
  2. You see mostly blue light; the other colors disappear.
  3. All of the colors turn red.

Which of the following models can explain what a red filter does to light?

  1. Filters add color to light - red adds red, and so on.
  2. Filters add a complementary color to light - red adds blue, for example.
  3. Light is like little bullets, but there are different kinds of bullets. Filters stop some bullets, but not others.

If the light hitting the prism goes through a red filter first, what will you end up seeing on the screen?

  1. The light that passes through the prism will be white.
  2. The light that passes through the prism will be red.
  3. The light that passes through the prism will be everything except red.
  4. No light will pass through the prism.

What is the meaning of the pictured experiment?

  1. Prisms create new colors from white light.
  2. Prisms add new colors to white light.
  3. White light is a mixture of light with different colors.
  4. Yellow light is a mixture of light with different colors.

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?

  1. The clothes will appear blue.
  2. The clothes will appear green.
  3. The clothes will appear black.
  4. The clothes will appear yellow.

A person's clothes appear dark red when the fluorescent lights (white light) are on. How will the person's clothes look when the street lamp (which ONLY releases yellow light) is on?

  1. The clothes will appear red.
  2. The clothes will appear orange.
  3. The clothes will appear black.
  4. The clothes will appear yellow.

If you look at a blue dot on the screen through a red filter, what will you see?

  1. A blue dot.
  2. A red dot.
  3. A black dot.
  4. A white dot.

If you look at a red dot on the screen through a blue filter, what will you see?

  1. A blue dot.
  2. A red dot.
  3. A black dot.
  4. A white dot.

Which of the waves below has the largest frequency?

Compared to other colors of visible light, red light has

  1. higher energy and longer wavelength.
  2. lower energy and longer wavelength.
  3. lower energy and shorter wavelength.
  4. higher energy and shorter wavelength.

The number line below has values increasing toward the right. Which quantities could this number line represent?

  1. wavelength
  2. frequency
  3. energy
  4. speed
  5. wavelength and energy
  6. frequency and energy

If you removed the green and orange light coming from an object that is releasing the mixture below, what would the spectrum look like?

Which of the following spectrums represents the light from red and blue TV dots?

Which of the following is true?

  1. Radio photons have a longer wavelength than visible light photons.
  2. X-ray photons have a larger frequency than visible light photons.
  3. Infrared photons have a smaller energy than visible light photons.
  4. All of the above.
  5. None of the above.


Thermal (Blackbody) Radiation

If you watch the filaments of a light bulb with your eyes alone, what will happen as I increase its temperature? After starting out dark, it will

  1. become faint and red, then bright and white.
  2. become faint and white, then bright and white.
  3. become faint and white, then bright and red.

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?

  1. red
  2. orange
  3. blue

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?

  1. Both colors get brighter.
  2. The color blue gets brighter, but the color red gets fainter.
  3. The color red gets brighter, but the color blue gets fainter.
  4. Both colors get fainter.

Which color will become visible last as the temperature of the light bulb filament is increased?

  1. red
  2. orange
  3. yellow
  4. green
  5. blue
  6. violet

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?

  1. The suspect is dark, but becomes bright after jumping in.
  2. The suspect is dark, even after jumping in the water.
  3. The suspect is bright, even after jumping in the water.
  4. The suspect is bright, but becomes dark after jumping in.

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.)

  1. Visible light
  2. Ultraviolet light (shorter wavelength)
  3. Infrared light (longer wavelength)
  4. The Earth is too cool to emit any of these kinds of light.

The graph below shows the spectrums for three different stars. Which of the stars has the highest temperature?


Types of Spectrum

The light from the Sun is a white light mixture. Based on what you know about their colors, which of the spectrums (light mixtures) below best represents what reflects off Mars?

Which of the following graphs probably represents the spectrum of Betelgeuse best? (Betelgeuse is a star that looks red to the eye.)

I have a jug of clear blue liquid. Which of the following is true?

  1. The liquid is not doing anything to the light that hits it.
  2. Most of the violet, blue, and green light is bouncing off the liquid and coming to your eyes.
  3. Most of the yellow, orange, and red light is bouncing off the liquid and coming to your eyes.

When I pass the jug of clear blue liquid in front of the light bulb, what will you see in the spectrum?

  1. The jug will make the violet, blue and green light more intense.
  2. The jug will make the yellow, orange, and red light more intense.
  3. The jug will remove most of the violet, blue, and green light.
  4. The jug will remove most of the yellow, orange and red light.

Which kind of spectrum would you see if you were looking in the direction shown by the arrow?

  1. continuous spectrum
  2. absorption line spectrum
  3. emission line spectrum

Which kind of spectrum would you see if you were looking in the direction shown by the arrow?

  1. continuous spectrum
  2. absorption line spectrum
  3. emission line spectrum

Which kind of spectrum would you see if you were looking in the direction shown by the arrow?

  1. continuous spectrum
  2. absorption line spectrum
  3. emission line spectrum

Imagine that you are looking at two different spectrums of the Sun. Spectrum #1 is obtained using a telescope in orbit high enough about Earth's atmosphere. Spectrum #2 is obtained using a telescope on Earth. Which spectrum comes from the telescope on Earth (#2)?


Atoms

The electrical force attracts an electron to a proton. To move an electron from a low orbit to a high orbit (farther from the proton), what has to happen?

  1. Energy has to be absorbed.
  2. Energy has to be released.
  3. Nothing has to happen - the electron will change orbits on its own.

A green photon must be absorbed to get an electron to move from the ground state to an excited state (a larger orbit). To get the electron to move to a higher excited state (an even larger orbit), what kind of photon might the electron be able to absorb?

  1. green
  2. red
  3. blue

An atom has energy levels with energies of 0, 3, and 5 units. The energy level with an energy of 5 units is the outermost boundary of the atom. Assuming this atom has a single electron in the "0" energy level (the ground state), which of the following photon energies can the electron absorb to move it to another orbit?

  1. 3 units only.
  2. 3 units or 2 units.
  3. 3 units or 5 units.
  4. 3 units or 8 units.
  5. 5 units only.
  6. 8 units only.

An atom has energy levels with energies of 0, 3, 9, and 10 units. The energy level with an energy of 10 units is the outermost boundary of the atom. Assuming this atom has a single electron in the "3" energy level, which of the following photon energies can the electron absorb but still remain attached to the atom? (There are two correct answers.)

  1. 1 unit.
  2. 3 units.
  3. 6 units.
  4. 7 units.
  5. 8 units.
  6. 9 units.
  7. 10 units.

Atom X has energy levels with energies of 0 and 10 units. Atom Y has energy levels with energies of 0 and 12 units. In each atom, an electron moves from the upper energy level to the lower energy level, emitting a single photon in the process. Which of the photons has longer wavelength?

  1. The photon from atom X.
  2. The photon from atom Y.
  3. The photons will have the same wavelength.


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?

  1. More than 99%
  2. About 75% (only a 1 in 4 chance they wouldn't)
  3. About 50%
  4. About 25% (only a 1 in 4 chance they would)
  5. Less than 1%

Which of the pictures below shows Earth correctly scaled in comparison to the Sun?

If you added together all of the planets, how would their mass compare to the mass of the Sun?

  1. The planets are miniscule compared to the Sun's mass.
  2. The planets add up to about half the Sun's mass.
  3. The planets add up to about the same as the Sun's mass.
  4. The planets add up to more than the Sun's mass.

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?

  1. He will start to spin much slower.
  2. He will keep spinning at the same speed.
  3. He will start to spin much faster.
  4. Something horrible will happen...

What will happen if he moves his arms up and down, parallel to his spin axis?

  1. He will start to spin much slower.
  2. He will keep spinning at the same speed.
  3. He will start to spin much faster.
  4. Something even more horrible will happen...

What would happen to a cloud that collapsed without any rotation at all?

  1. There would not be planets orbiting the Sun.
  2. The planets would be closer to the Sun.
  3. The planets would be farther from the Sun.

What kind of material would you expect to be able to condense out of the gas closest to the Sun?

  1. Snowflakes (icy material).
  2. Dust grains made of rocky material.
  3. Metallic dust grains.
  4. Liquid hydrogen droplets.

As the solar system was forming, where could chemicals like water be found?

  1. Everywhere (as a gas)
  2. Only near the Sun (as a gas)
  3. Near the Sun as a gas, and farther from the Sun as solid particles
  4. Only far from the Sun (as solid particles)
  5. Everywhere (as solid particles)

The dense terrestrial planets tend to be located nearer the Sun because

  1. it is predicted by Newton's Laws
  2. the gravity of the Sun affects them more.
  3. it was hotter near the Sun when these planets formed.

Which of the statements below correctly describes how comets differ from asteroids? (Give all correct statements.)

  1. Comets are mostly ices, not rock.
  2. Comets are usually much farther from the Sun.
  3. Comets are leftover pieces of bigger smashed objects.

Which of the following statements describes the meaning of condensation?

  1. Solid objects colliding and sticking.
  2. Solid objects colliding and breaking up.
  3. Solid or liquid material turning into gas.
  4. Gas turning into solid or liquid.

Which of the following pairs of planets formed at temperatures below the freezing point of water?

  1. Mercury and Venus
  2. Venus and Earth
  3. Mars and Jupiter
  4. Earth and Jupiter
  5. Jupiter and Saturn

Would it have been possible for a large Jupiter-like planet to form in the location of Mars?

  1. yes
  2. no

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

  1. more frequently.
  2. at about the same rate.
  3. less frequently.

Which of these facts is NOT explained by nebular theory?

  1. There are two main types of planets: terrestrial and jovian.
  2. Planets orbit in the same direction and plane.
  3. The existence of asteroids and comets.
  4. The number of planets of each type (4 terrestrial and 4 jovian).


Terrestrial Planet Geology

Mountain ranges form where plates are
  1. pushing against each other
  2. pulling apart.
  3. sliding by each other in opposite directions.
  4. sliding in the same direction.

Where are most of the volcanoes on Earth that have been mapped?

  1. Spread evenly on land and under the sea.
  2. Spread evenly on land.
  3. On land near the equator.
  4. Around the edges of the Atlantic Ocean.
  5. Around the edges of the Pacific Ocean.
  6. Around the edges of all of the continents.
  7. On islands.

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?

  1. The continental plate would be melted, along with the crater.
  2. More recent impacts would make craters that would erase the old ones.
  3. Lava flows from the volcano would cover it up over time.

In the image below, how heavily covered with craters is Mars?

  1. The surface was almost entirely covered with craters.
  2. There was a medium number of craters, spread all over the surface.
  3. There was a medium number of craters, mostly on one side of the planet.
  4. There were a small number of visible craters.
  5. There were no craters visible.

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?

  1. Planets that are closer to the Sun have more craters.
  2. Planets that are closer to the Sun have fewer craters.
  3. Larger planets have more craters.
  4. Larger planets have fewer craters.

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?

  1. The lava is probably older than most of the craters.
  2. The lava is probably about the same age as most of the craters.
  3. The lava is probably younger than most of the 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...

  1. late in the Moon's history.
  2. early in the Moon's history.
  3. regularly throughout the Moon's history.

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)?

In the picture of Mars' surface below, which is older?

  1. The large crater.
  2. The erosion channels.
  3. They are about the same age

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?

  1. Planets that are closer to the Sun have more volcanoes.
  2. Planets that are closer to the Sun have fewer volcanoes.
  3. Larger planets have more volcanoes.
  4. Larger planets have fewer volcanoes.
  5. There is no apparent relationship.

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?

  1. It should have no volcanic mountains.
  2. It should have volcanic mountains, but they may or may not be active.
  3. It should have a number of active volcanoes spread evenly over the surface.
  4. It should have a large number of active volcanoes found only in small areas of the surface.

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?

  1. 10 million years
  2. 20 million years
  3. 40 million years
  4. 80 million years
  5. 160 million years
  6. 320 million years

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.)

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

What would a large terrestrial planet be like today if it was far from the Sun?

  1. Many volcanoes and craters, and much erosion.
  2. Many volcanoes but few craters, and some erosion
  3. Many craters and much erosion, but few volcanoes.
  4. Many craters, but few volcanoes and little erosion.
  5. Few craters or volcanoes, and little erosion.


Planet Atmospheres

When light from the Sun passes through the gas in a planet's atmosphere, what happens?

  1. The gas removes light having specific wavelengths and produces an absorption line spectrum.
  2. The gas adds light having specific wavelengths and produces an emission line spectrum.
  3. The gas adds all kinds of light and produces a continuous spectrum.
  4. The gas doesn't do anything to the light, leaving a continuous spectrum.

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?

  1. A continuous spectrum
  2. An emission line spectrum
  3. An absorption line spectrum

Which of the following kinds of light from the Sun gets through Earth's atmosphere most easily and reaches the surface?

  1. ultraviolet
  2. visible
  3. infrared

What gas in Earth's atmosphere is suspected of causing global warming?

  1. ozone
  2. nitrogen
  3. carbon dioxide

What does carbon dioxide gas do in Earth's atmosphere?

  1. It allows infrared light to pass freely, but it blocks and absorbs visible light.
  2. It allows visible light to pass freely, but it blocks and absorbs infrared light.
  3. It allows visible and infrared light to pass freely, but it blocks ultraviolet light.

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?

What would Earth's temperature be like if Earth reflected more of the sunlight hitting it?

  1. It would be higher.
  2. It would be lower.
  3. It would be about the same as it is now.

In the flowchart below, where are the best places to put the following: A. NO CONDENSATION, B. MANY VOLCANOES, C. GREENHOUSE EFFECT, D. GRAVITY.

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.

In the flowchart below, where are the best places to put the following: A. GREENHOUSE EFFECT, B. GRAVITY, C. PLANT LIFE, D. OUTGASSING, E. LIQUID WATER.


Jovian Planets

Neptune is a deep blue color. Which of the following could be a reason for this?

  1. Neptune is hot enough to be releasing mostly blue light.
  2. Neptune is cold enough to be releasing mostly blue light.
  3. Gases in Neptune's atmosphere absorb most of the blue light coming from the Sun.
  4. Gases in Neptune's atmosphere absorb most of the red light coming from the Sun.

Jupiter's Great Red Spot is a deep red color. Which of the following could be a reason for this?

  1. The Spot is hot enough to be releasing mostly red light.
  2. The Spot is cool enough to be releasing mostly red light.
  3. Gases in the Spot absorb most of the blue light coming from the Sun.
  4. Gases in the Spot absorb most of the red light coming from the Sun.

Below is a picture of Saturn's moon Enceladus. Which of the following statements about its surface is probably true?

  1. All parts of its surface froze over at about the same time.
  2. The lower left part of the surface probably froze over before the upper right.
  3. The upper right part of the surface probably froze over before the lower left.

What happens to cans of diet tea and energy drink when put in water?

  1. The diet tea will float and the energy drink will sink.
  2. The diet tea will sink and the energy drink will float.
  3. Both will float in water.
  4. Both will sink 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...

  1. 0.2 times Jupiter's density.
  2. 0.6 times Jupiter's density.
  3. the same as Jupiter's density.
  4. 1.8 times Jupiter's density
  5. 3 times Jupiters' density.
  6. 5 times Jupiter's density.

What should happen to a rapidly spinning planet it it is mostly made of materials that aren't solid?

  1. It will bulge outward at its equator.
  2. It will bulge outward at its poles (like a football).
  3. It will become a bigger sphere.
  4. It will become a smaller sphere.
  5. Nothing really - it will just spin normally.


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?

  1. The Sun has roughly the same volume as Jupiter.
  2. The Sun has roughly 10 times the volume of Jupiter.
  3. The Sun has roughly 100 times the volume of Jupiter.
  4. The Sun has roughly 1000 times the volume of Jupiter.
  5. The Sun has roughly 10,000 times the volume of Jupiter.

If the Sun was a cooler star, what kind of light would be most intense?

  1. Infrared or visible red light.
  2. Ultraviolet or visible blue light.
  3. The most intense wavelength of light would be the same as it is now, but the Sun would be less bright.


Parallax

If you hold your thumb at arm's length and look at it with your left eye and your right eye separately, your thumb seems to move compared to the background. What happens if your thumb is closer to your head?

  1. Your thumb seems to move less when you switch between eyes.
  2. Your thumb seems to move the same amount when you switch.
  3. Your thumb seems to move more when you switch between eyes.
  4. Your thumb doesn't seem to move when you switch.

Imagine that you are looking at the stars from Earth in January. The picture in the frame shows a view of the distant stars as seen from Earth. Which number would star A appear above as seen by someone on Earth in January?

Which of the stars in the picture is closest to us?


Star Luminosity

Two light bulbs are the same distance away from you, but light bulb A puts out 100 watts and light bulb B puts out 50 watts. From your point of view, how are the light bulbs going to appear?

  1. Both bulbs will appear to be the same brightness.
  2. Bulb A will appear to be twice as bright as bulb B.
  3. Bulb B will appear to be twice as bright as bulb A.
  4. Bulb A will appear to be four times as bright as bulb B.
  5. Bulb B will appear to be four times as bright as bulb A.

You are studying at you desk under an unshaded lamp with a 100 watt light bulb. Your roommate moves the lamp so that it is twice as far away from you. How many 100-watt light bulbs would have to be used in the lamp to light your desk as bright as it was before?

  1. One bulb.
  2. Two bulbs.
  3. Three bulbs.
  4. Four bulbs.
  5. More than four bulbs.

You are studying at you desk under an unshaded lamp with a 100 watt light bulb. Your roommate moves the lamp so that it is twice as far away from you, but replaces it with a 200 watt bulb. How bright is your desk compared to earlier?

  1. 1/4th as bright.
  2. 1/2 as bright.
  3. The same brightness as before.
  4. 2 times as bright.
  5. 4 times as bright.

An Earth-sized planet orbits 3 AU from another star. The star has the same temperature as the Sun, but is 3 times more luminous than the Sun. What is the temperature on the planet probably like?

  1. It is probably warmer than Earth.
  2. It is probably cooler than Earth.
  3. It is probably about the same temperature as Earth.

If you know two stars have the same luminosity, but star A appears 100 times fainter than star B, how do their distances compare?

  1. Star A is 10,000 times farther away than star B.
  2. Star A is 100 times farther away than star B.
  3. Star A is 10 times farther away than star B.
  4. Star B is 10 times farther away than star A.
  5. Star B is 100 times farther away than star A.
  6. Star B is 10,000 times farther away than star A.


Some of the questions above are taken from the following sources:

J. P. Adams, D. J. Loranz, E. E. Prather, and T. F. Slater. Lecture Tutorials for Introductory Astronomy -- Instructor's Guide, 2002 (Prentice Hall).


Last update: October 29, 2014