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Astronomy

Key Concepts:

Terms in this set (118)

What is an astronomical unit?
A) The average distance between Earth and the Sun.
B) The distance light can travel in one year.
C) The unit used to describe time in astronomy
D) none of the above
A) The average distance between Earth and the Sun
What is a light year?
A light year is a measure of distance light can travel in one year.
What is our cosmic address?
universe>local supercluster>local group>Milky Way Galaxy>Solar System>Earth
Briefly explain what we mean by the statement "The farther away we look in the distance the further back we look in time."
It means that when we look at a distant object, we see it as it was some time in the past, rather than as it is now. This is because the light we see has taken time to travel from the object to us.
What is the age of the universe?
A) 2 billion years
B) 4.6 billion years
C) 14 million years
D) 14 billion years
D) 14 billion years
Our solar system consists of ______.
A) the Sun and all the objects that orbit it
B) a few hundred billion stars, bound together by gravity
C) the Sun and several nearby stars, as well as the planets and other objects that orbit these stars
D) the Sun and the planets, nothing else
A) the Sun and all the objects that orbit it
Why do we have seasons?
A) The tilt of Earth's axis causes the northern hemisphere to be closer to the Sun than the southern hemisphere in the summer, and vice versa in the winter.
B) The varying speed of Earth in its orbit around the Sun gives us summer when we are moving fastest and winter when we are moving slowest.
C) Earth's elliptical orbit means that we are closer to the Sun and therefore receive more intense sunlight at some times of the year than others.
D) The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.
D) The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.
A solar eclipse occurs during ____ moons.
New moons
A lunar eclipse occurs during ____ moons.
Full moons
How did the Greeks explain planetary motion?
The Greeks used a geocentric model, which explained apparent retrograde motion by having each planet move on a small circle whose center moves around Earth on a larger circle.
Why did ancient civilizations use astronomy?
A) To become scientists at a university
B) To figure out how to create telescopes
C) For navigation
D) To keep track of time and seasons
E) Both C & D
E) Both C & D
What is a hypothesis?
A tentative model proposed to explain some set of observed facts, but which has not yet been rigorously tested and confirmed; an educated guess
In science, a broad idea that has been repeatedly verified so as to give scientists confidence that it represents reality is called ______.
A) hypothesis
B) fact
C) theory
D) validation
C) theory
The difference between speed and velocity is that _____.
Velocity indicates direction, and speed does not.
When a spinning ice skater pulls in his arms, he spins faster because _____.
The radius has decreased, so his velocity increases. Remember angular momentum is equal to mass x velocity x radius.
What is escape velocity?
The speed necessary to escape the gravity of a large body
What is Earth's escape velocity?
11 km/s
Name the order of the wavelengths from longest to shortest in the electromagnetic spectrum.
radio, infrared, visible, ultraviolet, X rays, gamma rays
What are emission lines?
Emission lines show up on a dark background with a bright colored line.
What are absorption lines?
Absorption lines show up on a bright colored background with dark colored lines.
The terrestrial planets in our solar system are _____.
A) Jupiter, Saturn, Uranus, and Neptune
B) Pluto and Eris
C) Mercury, Venus, Earth, and Mars
D) Mars, Jupiter, Saturn, Uranus, and Neptune
D) Mars, Jupiter, Saturn, Uranus, and Neptune
The jovian planets in our solar system are ______.
A) Mercury, Venus, Earth, and Mars
B) Jupiter, Saturn, Uranus, and Neptune
C) Io, Europa, Ganymede, and Callisto
D) Pluto and Eris
B) Jupiter, Saturn, Uranus, and Neptune
According to modern scientific dating techniques, approximately how old is the solar system?
4.5 billion years old
The process by which small "seeds" grew into planets is called _____.
accretion
What is the difference between comets and asteroids?
Comets are icy bodies that formed outside the frost line, and asteroids are rocky bodies that formed inside the frost line
Where is the Kuiper belt located?
A) Between Mars and Jupiter
B) Beyond Pluto's orbit
C) Located in a sphere around the Milky Way
D) Beyond Neptune's orbit
D) Beyond Neptune's orbit
What is the magnetosphere?
A) the layer of a planet in which its magnetic field is generated
B) a region of space around a planet in which the planet's magnetic field can trap charged particles
C) the region in a planet's atmosphere in which auroras occur
D) the uppermost layer of any planetary atmosphere
B) a region of space around a planet in which the planet's magnetic field can trap charged particles
What are the processes responsible for virtually all surface geology?
A) convection, conduction, and radiation
B) accretion, differentiation, and radioactive decay
C) impact cratering, volcanism, tectonics, and erosion
D) eruptions, lava flows, and outgassing
C) impact cratering, volcanism, tectonics, and erosion
What is the disruption of a planet's surface by internal stresses called?
tectonics
What geological features indicate that water once flowed on Mars?
Dry riverbeds, eroded craters, and the minerals found there
What is the basic definition of a greenhouse gas?
A. a gas that makes a planet much hotter than it would be otherwise, even in small amounts
B. a gas that absorbs infrared light
C. a gas that reflects a lot of sunlight
D. a gas that keeps warms air from rising, and therefore warms the surface
B. a gas that absorbs infrared light
What are the three common greenhouse gases?
carbon dioxide, water vapor, methane
What is the importance of the carbon dioxide cycle?
A) It allows for an ultraviolet-absorbing stratosphere.
B) It will prevent us from suffering any consequences from global warming.
C) It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.
D) It makes the growth of continents possible.
C) It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.
Lunar maria are _____.
Smooth dark features on the Moon that are sites of large impacts later flooded by lava
Why do the jovian planets decrease in size away from the Sun?
A) This isn't true, the way we view the planets in the night sky makes them appear this way.
B) The jovian planets have different sized cores and the ones closest to the Sun have larger cores, so
they are bigger.
C) The jovian planets farther from the Sun took longer to form and captured less hydrogen and helium.
D) The jovian planets farther from the Sun were impacted by larger craters, so they could not develop into larger planetesimals.
C) The jovian planets farther from the Sun took longer to form and captured less hydrogen and helium.
Why are jovian moons more geologically active than small rocky planets?
A) molten cores of metallic hydrogen allowing circulation in interiors of moons
B) tidal heating causing internal heating of moons
C) impact craters sharing energy with the moons
D) none of the above
B) tidal heating causing internal heating of moons
Suppose you could float in space just a few meters above Saturn's rings. What would you see as you looked down on the rings?
Countless icy particles, ranging in size from dust grains to large boulders
What molecule is responsible for absorbing UV radiation?
ozone
What is the Big Bang theory?
The event that marked the beginning of the universe
What is a meteorite?
A rock found on Earth that crashed down from space
Asteroids exist between what two planets' orbits?
A. Beyond Neptune's orbit
B. In the Oort Cloud
C. Between Mercury and Venus's orbits
D. Between Mars and Jupiter's orbits
D. Between Mars and Jupiter's orbits
How is Pluto classified?
A. An asteroid
B. A minor planet
C. A large member of the Kuiper belt
D. A white dwarf
C. A large member of the Kuiper Belt
Why are there very few asteroids beyond Jupiter's orbit?
A. The heaviest rocks sank toward the center of the solar system.
B. Ice could form in the outer solar system.
C. A passing star probably stripped away all of those asteroids, even if they were there at one time.
D. There was no rocky material beyond Jupiter's orbit.
B. Ice could form in the outer solar system.
What is an extrasolar planet?
a planet that orbits our star that is not our own Sun
The Kepler mission searched for extrasolar planets using what method?
A. obtaining high-resolution photographs of other star systems.
B. monitoring stars for slight dimming that might occur as unseen planets pass in front of them.
C. looking for slight back and forth shifts in a star's position in our sky.
D. observing Doppler shifts in a star's spectrum caused by an unseen planet.
B. monitoring stars for slight dimming that might occur as unseen planets pass in front of them.
What do we mean by a "hot Jupiter"?
A. a planet that is Jupiter-like in size but Earth-like in density
B. a planet that has a Jupiter-like orbit but is more massive and therefore has a higher internal temperature
C. a planet that is Jupiter-like in size but orbits very close to its star
D. a planet that has a Jupiter-like orbit but is made of high-melting point materials such as rock and metal
C. a planet that is Jupiter-like in size but orbits very close to its star
Direct detection of an extrasolar planet means ____.
acquiring images or spectra of the planet
Indirect detection of an extrasolar planet means _____.
observing the planet's effect on its host star
According to modern science, approximately how old is the Sun?
4.5 billion years old
The source of energy that keeps the Sun shining today is _____.
hydrogen fusion
From center outward list the layers of the Sun.
A. core, radiation zone, convection zone, corona, chromosphere, photosphere
B. core, convection zone, radiation zone, corona, chromosphere, photosphere
C. core, corona, radiation zone, convection zone, photosphere, chromosphere
D. core, radiation zone, convection zone, photosphere, chromosphere, corona
D. core, radiation zone, convection zone, photosphere, chromosphere, corona
What is the solar wind?
A. the strong wind that blows sunspots around on the surface of the Sun
B. a stream of charged particles flowing outward from the surface of the Sun
C. the uppermost layer of the Sun, lying just above the corona
D. the wind that causes huge arcs of gas to rise above the Sun's surface
B. a stream of charged particles flowing outward from the surface of the Sun
From hottest to coolest, the order of the spectral type of stars is _____.
A. OBAFGKM
B. ABCDEFG
C. ABFGKMO
D. OBAGFKM
E. OMKGFBA
A. OBAFGKM
The axes on the Hertzsprung-Russell (H-R-) diagram represent ____.
A. mass and luminosity
B. luminosity and apparent brightness
C. luminosity and surface temperature
D. mass and radius
C. luminosity and surface temperature
How is the lifetime of a star related to its mass?
A. More massive stars live slightly longer lives than less massive stars.
B. More massive stars live much shorter lives than less massive stars.
C. More massive stars live slightly shorter lives than less massive stars.
D. More massive stars live much longer lives than less massive stars.
B. More massive stars live much shorter lives than less massive stars.
What is the common trait of all main sequence stars?
They generate energy through hydrogen fusion in their core
What is a protostar?
A. a star in its final stage of life
B. a star that is still in the process of forming
C. an intermediate-mass star
D. a star that has planets
B. a star that is still in the process of forming
What are the stages of the life of a low mass star in order from youngest to oldest?
protostar, main-sequence star, red giant, planetary nebula, white dwarf
What is the ultimate fate of our Sun?
A. explode in a supernova
B. become a black hole
C. become a white dwarf that will slowly cool with time
D. become a rapidly spinning neutron star
C. become a white dwarf that will slowly cool with time
After a supernova explosion, the remains of the stellar core _____.
A. will always be a black hole
B. will always be a neutron star
C. may be either a neutron star or a black hole
D. may be either a white dwarf, neutron star, or black hole
C. may be either a neutron star or a black hole
A spinning neutron star is defined as a ____.
pulsar
Identify the order of life events for a high mass star.
Main sequence, red supergiant, supernova, neutron star
A white dwarf is ____.
A. a star that follows a period-luminosity relation
B. the remains of a star that ran out of fuel for nuclear fusion
C. a main-sequence star of spectral type F, which tends to look white in color
D. a type of star that produces energy by gravitational contraction
B. the remains of a star that ran out of fuel for nuclear fusion
Wind speed is fastest on ___ when comparing jovian planets.
Saturn
Radiative energy is _____.
A. energy of motion
B. heat energy
C. energy carried by light
D. energy from nuclear power plants
C. energy carried by light
We can see each other in the classroom right now because we _____.
A. emit thermal radiation.
B. emit visible light.
C. emit infrared light.
D. reflect visible light.
E. reflect infrared light.
D. reflect visible light.
What is the purpose of adaptive optics?
A. It allows several small telescopes to work together like a single larger telescope.
B. It is a special technology that allows the Hubble Space Telescope to adapt to study many different types of astronomical objects.
C. It allows ground-based telescopes to observe ultraviolet light that normally does not penetrate the atmosphere.
D. It reduces blurring caused by atmospheric turbulence for telescopes on the ground.
D. It reduces blurring caused by atmospheric turbulence for telescopes on the ground
The nebular theory holds that ___.
our solar system formed from the collapse of an interstellar cloud of gas and dust
In the formula E = mc2, what does E represent?
A. the gravitational potential energy of an object held above the ground
B. the electric field produced by a charge
C. the radiative energy carried by light
D. the kinetic energy of a moving object
E. the mass-energy, or potential energy stored in an object's mass
68. E. the mass-energy, or potential energy stored in an object's mass
If the hypothesis tracing the extinction of the dinosaurs to an impact is correct, the dinosaurs died off largely because ___.
65 million years ago of global climate effects initiated by dust and smoke that entered the atmosphere after the impact
Where does star formation occur in the Milky Way Galaxy?
spiral arms
What object do we think lies in the center of the Milky Way Galaxy?
A. an enormous collection of dark matter, explaining why we detect no light at all from the galactic center
B. a dense cluster of young, hot stars
C. a gigantic X-ray binary system
D. a 3 to 4 million solar mass black hole
D. a 3 to 4 million solar mass black hole
What is the definition of a black hole?
an object with gravity so strong that not even light can escape
What does the event horizon represent?
A. It is the distance from the black hole at which stable orbits are possible.
B. It is the point beyond which neither light nor anything else can escape.
C. It is the very center of the black hole.
D. It is the place where X-rays are emitted from black holes.
B. It is the point beyond which neither light nor anything else can escape.
What do we mean by a primitive meteorite?
A. a meteorite that fell to Earth at least 4 billion years ago
B. a piece of rock that is essentially unchanged since it first condensed and accreted in the solar nebula some 4.6 billion years ago
C. a type of meteorite that is usually made mostly of high-density metals
D. a meteorite that was discovered by primitive people
B. a piece of rock that is essentially unchanged since it first condensed and accreted in the solar nebula some 4.6 billion years ago
If you view the solar system high above Earth's North Pole. Which of the following statements about the orbits will be true?
A. The inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise.
B. All the planets orbit counterclockwise around the Sun.
C. All the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction.
D. The inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise.
B. All the planets orbit counterclockwise around the Sun.
Gravity is so strong in a black hole that _____.
nothing can escape it - not even light
Planetary nebulae form from what type of star?
low-mass star
What event caused gravitational waves to be detected?
merging of two black holes
What is LIGO?
Laser Interferometer Gravitational-wave Observatory
Where are the observatories located?
Livingston, Louisiana and Hanford, Washington
What causes gamma ray bursts?
formation of black holes and collisions of neutrons stars
Globular clusters are located in which part of the Milky Way galaxy?
halo
The central region of the Milky Way is called the _____.
bulge
84. What type of wavelength is used to see past clouds of dust and gas?
infrared
After the formation of atomic hydrogen gas, what forms?
molecular cloud
What wavelengths do we use to view atomic hydrogen gas?
A. Infrared
B. Radio (21cm)
C. Ultraviolet
D. Visible
B. Radio (21cm)
Which type of stars contains heavier elements?
A. Stars in globular clusters
B. Stars within the bulge
C. Stars located within open clusters
D. None of the above
C. Stars located within open clusters
Pulsars are thought to be ______.
A. accreting white dwarfs
B. unstable high-mass stars
C. rapidly rotating neutron stars
D. accreting black holes
C. rapidly rotating neutron stars
Where does most star formation occur in the Milk way Galaxy?
A. central bulge
B. halo
C. spiral arms
D. disk
C. spiral arms
What are the two principle advantages of using telescopes over eyes?
A. Telescopes collect more light and are unaffected by twinkling.
B. Telescopes have much more magnification and better angular resolution.
C. Telescopes can collect far more light with far greater magnification.
D. Telescopes can collect far more light with far better angular resolution.
D. Telescopes can collect far more light with far better angular resolution.
What is the Copernican Revolution?
When we learned that the Earth is a planet orbiting the Sun rather than the center of the universe
What is the importance of Galileo in the Copernican Revolution?
A. Made more accurate observations than anyone before
B. Thought of the idea of circles moving on circles (epicycles) to explain planet's motion
C. Realized orbits could be ellipses
D. Experiments and observations overcame remaining scientific objections of Copernican Revolution
E. Sun center of solar system
D. Experiments and observations overcame remaining scientific objections of Copernican Revolution
What are the 6 assumptions of science?
1. The world is real.
2. Humans can accurately perceive the universe.
3. Natural processes are sufficient to explain natural events.
4. Our perceptions maybe biased or inaccurate.
5. Scientific explanations are limited.
6. Scientific explanations are probabilistic.
Nicolas Copernicus was important to astronomy because he _____.
A) developed a sun-centered model for the solar system.
B) made the best measurements with the naked eye on planetary positions
C) Hired Galileo to work on discovering laws of planetary motion
D) created the library in Alexandria
A) developed a sun-centered model for the solar system.
Ptolemy advanced astronomy by ____.
developed a model of the solar system that made sufficiently accurate predictions of planetary positions that it was used for a while using the idea of circles moving on circles (epicycles) to explain planet's motion
How are wavelength, frequency, and energy related when studying light waves?
A. Longer wavelength means higher frequency and lower energy.
B. Longer wavelength means lower frequency and higher energy.
C. Longer wavelength means lower frequency and lower energy.
D. Longer wavelength means higher frequency and higher energy.
E. There is no simple relationship because different photons travel at different speeds.
C. Longer wavelength means lower frequency and lower energy.
How do we describe the universe?
The sum total of all matter and energy
What is the Doppler effect?
effect that shifts the wavelengths of spectral features in objects that are moving toward or away from the observer
What light from human sources makes it difficult to see the stars at night?
light pollution
A photon is ____.
When considering light as made up of individual "pieces," each characterized by a particular amount of energy, these pieces are called photons.
Why is our galaxy called the Milky Way?
A. Farmers were the first to observe it while milking cows.
B. Band of light looked like a flowing ribbon of milk to ancient Greeks.
C. Herman Milky was the first to observe it in the night sky.
D. None of the above
B. Band of light looked like a flowing ribbon of milk to ancient Greeks.
What is the difference between a star and a planet?
Stars emit light whereas planets reflect light; stars orbit center of galaxy and planets orbit stars.
Who developed the spectral classification?
A. Edward Pickering
B. Annie Jump Cannon
C. Albert Einstein
D. Kepler
B. Annie Jump Cannon
Which telescope is used to view x-ray emissions?
A. Chandra
B. Spitzer
C. Hubble
D. None of the above
A. Chandra
How is the sunspot cycle directly relevant to us here on Earth?
A. The sunspot cycle strongly influences Earth's weather.
B. The Sun's magnetic field, which plays a major role in the sunspot cycle, affects compass needles that we use on Earth.
C. The brightening and darkening of the Sun that occurs during the sunspot cycle affects plant photosynthesis here on Earth.
D. The sunspot cycle is the cause of global warming.
E. Coronal mass ejections and other activity associated with the sunspot cycle can disrupt radio communications and knock out sensitive electronic equipment.
E. Coronal mass ejections and other activity associated with the sunspot cycle can disrupt radio communications and knock out sensitive electronic equipment.
A brown dwarf is _____.
object too small to become a star because electron degeneracy pressure halts gravitational collapse before fusion becomes self-sustaining
What is a white dwarf?
A. a star that follows a period-luminosity relation
B. the remains of a star that ran out of fuel for nuclear fusion
C. a main-sequence star of spectral type F, which tends to look white in color
D. a type of star that produces energy by gravitational contraction
B. the remains of a star that ran out of fuel for nuclear fusion
Gamma ray bursts are caused by ______.
formation of black holes and collisions of neutrons stars
Ceres is _____.
A. the largest asteroid discovered
B. the largest comet discovered in the Kuiper belt
C. a moon of Uranus
D. None of the above
A. the largest asteroid discovered
Where is the Oort cloud located?
spherical region of space centered around our Sun
What objects are located in the Oort cloud?
A. stars
B. comets
C. asteroids
D. planets
E both C and D
B. comets
Which moon has lakes of liquid methane?
A. Titan
B. Io
C. Ganymede
D. Ceres
A. Titan
Jupiter's core is made of ____.
core mix of hydrogen compounds, rock, and metal
What moon of Jupiter is likely to have a deep, subsurface ocean of liquid water?
A. Europa
B. Ganymede
C. Io
D. None of the above
A) Europa
What is the great red spot?
A) a hurricane that comes and goes on Jupiter
B) a long-lived, high-pressure storm on Jupiter
C) a place where reddish particles from Io impact Jupiter's surface
D) a place where ammonium sulfide clouds are concentrated
E) a region on Jupiter where the temperature is so high that the gas glows red visible light
B) a long-lived, high-pressure storm on Jupiter
Why is Venus so hot?
Runaway greenhouse affect
Why did Mars become so cold?
A change in Mars' magnetic field caused it to lose its protective magnetosphere, which caused the solar wind to strip away water vapor in the atmosphere.
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