1. A light-year is about 10 trillion kilometers
  2. It's about 4 light-years from here to Alpha Centauri
  3. The Milky Way Galaxy is about 100,000 light-years in diameter
  4. It will take the Voyager spacecraft about 20,000 years to travel just 1 light-year
  5. It will take me light-years to complete this examination


  1. Without galaxies, the universe could not be expanding
  2. Without galaxies, there could not have been a Big Bang
  3. Galaxies Prevent planets from leaving their orbits around stars; e.g. our galaxy prevents the earth from leaving its orbits of the Sun
  4. Galaxies provide the gravity that prevents us from falling off the earth
  5. Galaxies recycle heavy elements produced in stars into future generations of stars


  1. The Northern Hemisphere is tilted away from the Sun and received more indirect sunlight
  2. The Northern Hemisphere is "on top" of the earth and therefore receives sunlight
  3. The Norther Hemisphere is closer to the Sun than the Southern Hemisphere
  4. The Northern Hemisphere is tilted towards the Sun and receives more direct sunlight
  5. It is not: both hemispheres have the same seasons at the same time


  1. The moon goes through a cycle of phases because it always has the same side facaing the earth
  2. If you see a full Moon from North America, someone in South America would see a new moon
  3. The side of the Moon facing away from the earth is in perpetual darkness
  4. The Moon is visible only at night
  5. The Moon's distance from the earth varies during its orbit


  1. Atmosphere of Venus is very similar to that of Earth
  2. The mass of Jupiter can be calculated by measuring the orbital period and distance of one of Jupiter's moons
  3. The corona and chromosphere are hotter than the photosphere
  4. Galaxy collisions are more common in the past
  5. Some galaxy clusters are still growing today


  1. Mars
  2. the Sun
  3. Jupiter
  4. Saturn
  5. Venus


  1. They did detect it, but they rejected the observations
  2. They did not observe for long enough period of time
  3. They could not see distant stars
  4. They did not have the ability to measure very small angles
  5. They did not look for it


  1. All models that explain nature well are correct
  2. A model tries to represent all aspects of nature
  3. A model tries to represent only one aspect of nature
  4. A model can be used to explain and predict real phenomena
  5. All current models are correct


  1. It held that the planets moved along small circles that moved on larger circles around the Earth, and that the combined motion sometimes resulted in backward motion.
  2. It held that the planets resided on giant spheres that sometimes turned clockwise and sometimes turned counterclockwise.
  3. It held that sometimes the planets moved backwards along their circular orbits.
  4. It held that the planets moved along small circles that moved on larger circles around the Sun
  5. It placed the Sun at the center so that the planets apparent retrograde motion was seen as the earth passed each one in its orbit
  6. It varied the motion of the celestial sphere so that it sometimes moved backward.


  1. Aristotle
  2. Ptolemy
  3. Kepler
  4. Galileo
  5. Tycho Brahe


  1. Green is green in colour because it absorbs green light but reflects all other colours
  2. Stars are continually forming in the halo of our Galaxy today
  3. Although antimatter is an interesting theoretical idea, there is no evidence that it actually exists
  4. X-ray, which has more energy, travels faster through space than visible light
  5. The upper limit to the mass of a white drawf is 1.4 solar masses


  1. The star is getting hotter.
  2. The star is getting colder.
  3. The "star" actually is a planet.
  4. The star is moving toward us.
  5. The star is moving away from us.


  1. the retrograde rotation of Triton around Neptune
  2. the counterclockwise rotation of Venus
  3. the large size of Earth's Moon
  4. the rings of Saturn
  5. the extreme axis tilt of Uranus


  1. Mercury, because it is closest to the Sun
  2. Mercury, because of its dense carbon dioxide atmosphere
  3. Venus, because of its dense carbon dioxide atmosphere
  4. Mars, because of its red color
  5. Jupiter, because it is so big


  1. Size and distance from the Sun
  2. Internal temperature and atmosphere
  3. Size and chemical composition
  4. Distance from the sun and atmosphere
  5. Size and atmosphere


  1. Faster rotation rates produce stronger winds.
  2. The rotation rate determines how long the planet is able to retain its atmosphere.
  3. Faster rotation rates raise surface temperatures and thus determine how much material is gaseous versus icy or liquid.
  4. Faster rotation rates raise the atmospheric temperature.
  5. The rotation rate determines how much atmosphere a planet has.


  1. The Big Bang predicts that one in four atoms in the universe is helium
  2. Accretion and radioactivity are the two internal energy sources that produce heat by converting gravitation potential energy into thermal energy
  3. According to the theory of the solar system formation, the original solar nebula happened to be disk-shaped by chance
  4. The spiral arms of a spiral galaxy are brought because they contain more hot young stars than other parts of the disk
  5. The elements heavier than hydrogen and helium come from the Big Bang


  1. turn into pure energy
  2. remain stationary.
  3. attract each other.
  4. repel each other.
  5. join together to form a nucleus.


  1. The number of sunspots peaks approximately every 11 years.
  2. With each subsequent peak in the number of sunspots, the magnetic polarity of the Sun is the reverse of the previous peak.
  3. The rate of nuclear fusion in the Sun peaks about every 11 years.
  4. The cycle is truly a cycle of magnetic activity, and variations in the number of sunspots are only one manifestation of the cycle.
  5. The number of solar flares peaks about every 11 years.


  1. The strong force and the weak force.
  2. The gravitational force and surface tension.
  3. The gravitational force and outward pressure.
  4. The strong force and the electromagnetic force.
  5. The gravitational force and the weak force


  1. lower right
  2. upper right
  3. upper left
  4. lower left
  5. none of the above


  1. There is no auroras on Venus because it lacks atmospheric oxygen
  2. There is no gravity in space
  3. No visible light can escape a black hole, but gamma rays, X-rays and neutrinos can
  4. Based on all we know about the terrestrial worlds, its size is the single factor appears to play the most important role in a terrestrial planet's geological destiny
  5. The habitable zone around a star refers to the places where living organisms are found


  1. All stars in the cluster are approximately the same color.
  2. All stars in the cluster are approximately the same age.
  3. All stars in the cluster have approximately the same mass.
  4. All stars in the cluster will evolve similarly.
  5. There is an approximately equal number of all types of stars in the cluster.


  1. S
  2. G
  3. F
  4. M
  5. Z


  1. Sirius has a higher core temperature than Rigel.
  2. Rigel has a higher surface temperature than Sirius.
  3. Sirius has a higher surface temperature than Rigel.
  4. Rigel has a higher core temperature than Sirius.
  5. Sirius and Rigel have the same temperature


  1. Brown dwarfs form like ordinary stars but are too small to sustain nuclear fusion in their cores.
  2. All brown dwarfs have masses less than about 8% that of our Sun.
  3. Brown dwarfs are supported by a type of pressure, called degeneracy pressure, that does not depend on the object's temperature.
  4. Brown dwarfs will eventually collapse to become white dwarfs.
  5. Brown dwarfs and Jupiter are of similar sizes


  1. All stars that become supernovae will leave behind a neutron star
  2. One of the four Galilean moons Europa around Jupiter is made of rock
  3. We can see most of the galaxy with visible light
  4. Neptune is denser than Saturn because it has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks
  5. Over the course of the year, all 88 constellations will at some point be visible in the evening sky


  1. the galaxy's halo
  2. the galaxy's bulge
  3. the galaxy's disk
  4. a globular cluster
  5. an open cluster


  1. Its luminosity and its mass.
  2. Its mass and its distance.
  3. Its shape and its color
  4. The period between its peaks of brightness and its luminosity.
  5. The period between its peaks of brightness and its distance.


  1. It is 400 million years old.
  2. it is 1 billion years old.
  3. It is now 1 billion light-years away.
  4. It was 1 billion light-years away when the light left the galaxy.
  5. Its light traveled through space for 1 billion years to reach us.


  1. The heaviest element produced by stars or in supernovae is silicon
  2. Mars appearing red in colour is a result of the scattering of light in the Martian sky
  3. Some stars are cool enough to have molecules in their atmosphere
  4. The tides on Earth are an example of Newton's third law of motion quiz answer
  5. All comets orbit the Sun in the same direction as the planets


  1. The overall arrangement of galaxies, clusters of galaxies, and superclusters in the universe.
  2. Any individual cluster of galaxies is considered a large-scale structure.
  3. The overall shape of the observable universe.
  4. Any individual galaxy is considered a large-scale structure.
  5. The arrangement of stars in a galaxy


  1. Expansion of the universe affects only empty space, not space in which matter is present.
  2. The universe is not old enough yet for these objects to have begun their expansion.
  3. Space IS expanding within clusters of galaxies, which is why clusters tend to grow in size with time.
  4. Their gravity is strong enough to hold them together even while the universe as a whole expands.
  5. There is not enough matter in the clusters to repel the galaxies away


  1. They can form a complete atom.
  2. The combined mass-energy of the two particles is completely transformed into radiation-energy (two photons).
  3. They fuse to make a heavier particle.
  4. The question makes no sense, since antimatter does not really exist.
  5. They merge to form a molecule.


  1. Asteroids are usually found between the orbits of Mars and Jupiter
  2. The great contribution of tycho brahe was to observe planetary positions with sufficient accuracy so that kepler could later use the data to discover the laws of planetary motion
  3. Sunspots are cooler than the surrounding region of the sun's surface
  4. In our solar system, the jovian planet Jupiter has the largest size
  5. Almost all elements heavier than hydrogen and helium were made inside stars


  1. Makes it slow down.
  2. Stretches its wavelength.
  3. Makes all light infrared.
  4. Makes it brighter.
  5. Makes it dimmer


  1. whether the black hole formed in a massive-star supernova or in some other way
  2. the radius of the black hole, as measured by careful observations of its size
  3. both the mass and the chemical composition of the black hole
  4. only the mass of the black hole
  5. the colour of the black hole


  1. The apparent brightness of a star depends only on its luminosity
  2. All stars spend approximately the same amount of time on the main sequence.
  3. The faster rotating star has wider spectral lines than the slower rotating star.
  4. There is no upper limit to the mass of a neutron star
  5. There is no limit to the mass with which a star can be born


  1. Jupiter's atmosphere
  2. Europa
  3. Mars
  4. Ganymede
  5. All of the above


  1. It magnifies the effects of gravity that we see in the cluster.
  2. The overall shape of the cluster is that of a lens.
  3. It is an unusually large cluster that has a lot of gravity.
  4. It bends or distorts the light coming from galaxies located behind it.
  5. The shape of each galaxy in the cluster is that of a lens


  1. The strength of Coriolis effect is dependent only on the rotation rate of a planet
  2. Most of the current star formation in the Milky Way occurs in spiral arms (this is the right answer)
  3. Our Sun will likely undergo a nova event in about 5 billion years
  4. The gradual disappearance of a crater rim as a result of wind and rain is an example of tectonics
  5. Doubling the distance between two objects halves the gravitational force between them (check properly gravitational force decreases 4 times not twice)


  1. hydrogen fusion in the core.
  2. hydrogen fusion in a shell surrounding the central core.
  3. helium fusion in the core.
  4. gravitational contraction.
  5. nuclear fission in the core


  1. The mass of a neutrino is 20 percent of the mass of an electron
  2. Neutrinos are created as a by-product of proton-proton chain
  3. About a thousand trillion neutrinos are passing through your body every second.
  4. Neutrinos have no electrical charge.
  5. Neutrinos have a tendency to pass through just about anything without interactions, making them very difficult to detect.  


  1. 0
  2. +6 check properly this is the right answer (the higher the positive number the fainter the star)
  3. -6
  4. +1
  5. +10


  1. It does not have rain.
  2. It has sulfuric acid rain that causes erosion on the surface. --> should be the correct answer: http://www.astro.washington.edu/users/nms/teaching/a150winter2013/slides/l08_TerraAtmos.pdf; http://blogearth.wordpress.com/2008/02/23/venus-the-planet-where-it-rains-acid/
  3. It has sulfuric acid rain in its atmosphere, but the drops evaporate before hitting the surface. neither of you are right, since when it rain liquid water... and since when venus temperature allow either liquid water or acid to form on the surface....
  4. It has liquid water rain that causes erosion on the surface.
  5. It has liquid water rain in its atmosphere, but the drops evaporate before hitting the surface. check properly the drops will evaporate because venus is the HOTTEST planet due to the CO2 atmosphere


  1. The atmospheric pressure decrease as you go higher in altitude of Earth because gravity gets much weaker with altitude false(quiz answer)
  2. One of the reasons astronomers would like an observatory on the far side of the Moon is the telescope could observe stars even when it is daytime on the Moon true(quiz answer)
  3. The proton-proton chain converts four hydrogen nuclei into one helium nucleus true(quiz answer)
  4. The more distant a star, the smaller its parallax true(yahoo answer
  5. In any star cluster, stars with lower masses greatly outnumber those with higher masses true(yahoo answer)


  1. Planets cannot have stable orbits around high-mass stars.
  2. The stars are too hot to allow for life.
  3. The lifetime of a high-mass star is too short.
  4. The high-mass stars emit too much ultraviolet radiation.
  5. They emit too much ultraviolet radiation


  1. An object always has the same amount of energy.
  2. Energy can change between many different forms, such as potential, kinetic and thermal, but it is ultimately destroyed.
  3. The total quantity of energy in the universe never changes.
  4. It is not really possible for an object to gain or lose potential energy, because energy cannot be destroyed.
  5. The fact that you can fuse hydrogen into helium to produce energy means that helium can be turned into hydrogen to produce energy


  1. The clock will fall toward the black hole at a steady rate, so that you’ll see it plunge through the event horizon within just a few minutes.
  2. The clock will fall faster and faster, reaching the speed of light as it crosses the event horizon.
  3. Time on the clock will run slower as it approaches the black hole, and light from the clock will be increasingly redshifted.
  4. Time on the clock will run faster.
  5. Time on the clock will run faster as it approaches the black hole, and light from the clock will be increasingly blueshifted
  6. Time on the clock will run slower as it approaches the black hole, and light from the clock will be increasingly blueshifted


  1. The Moon's umbra must touch the area where you are located.
  2. Earth must lie completely within the Moon's umbra.
  3. Earth must be near aphelion in its orbit of the Sun.
  4. Earth must lie completely within the Moon's penumbra.
  5. The Moon's penumbra must touch the area where you are located.


  1. Motion of our Moon
  2. Orbital motion of Earth around our Sun
  3. Rotational motion of Earth
  4. Precession of Earth's axis of rotation
  5. Rotational motion of our solar system around Milky Way Galaxy


  1. craters
  2. maria
  3. penumbra
  4. umbra
  5. volcanoes


  1. The observer perceives that the source emits only red light
  2. The observer perceives that the source emits only blue light (choose only red or blue since its moving towards viewer its blue moving away is red)
  3. The observer does not observe any visible light emitted from the source
  4. Both 1 and 3
  5. Both 2 and 3


  1. The process of splitting nuclei to produce energy
  2. The process of combining lightweight nuclei to make heavier nuclei
  3. A process of turning matter into pure energy
  4. The process that only occurs in bombs
  5. An explosion caused by putting together two volatile chemicals


  1. Several minutes
  2. Several thousand years
  3. Several weeks
  4. Several days
  5. Several billions of years


  1. the tilt of the earth's axis
  2. baseball on television
  3. interference from the full moon
  4. the location of the earth in its orbit
  5. the precession of the earth's axis


  1. The phase of the Moon must be new, and the Moon’s orbital plane must lie in the ecliptic.
  2. The phase of the Moon can be new or full, and the nodes of the Moon’s orbit must be nearly aligned with Earth and the Sun.
  3. The phase of the Moon must be full, and the nodes of the Moon’s orbit must be nearly aligned with Earth and the Sun.
  4. The phase of the Moon must be new, and the nodes of the Moon’s orbit must be nearly aligned with Earth and the Sun.
  5. The phase of the Moon must be full, and the Moon’s orbital plane must lie in the ecliptic.


  1. was the first to believe that all orbits are perfect circles
  2. developed the first scientific model of the universe
  3. developed a model of the solar system that made sufficiently accurate predictions of planetary positions to remain in use for many centuries
  4. was the first to create a model of the solar system that placed the Sun rather than the Earth at the center
  5. was the first to believe in an Earth-centered universe


  1. Copernicus placed the planets in the wrong order going outward from the Sun.
  2. Copernicus used perfect circles for the orbits of the planets.
  3. Copernicus misjudge the distances between the planets
  4. Copernicus placed the Sun at the center , but did not realize that the Moon orbits the earth
  5. Copernicus did not consider the self-rotational speed of the planets


  1. The rock keeps the energy inside it in the form of mass-energy.
  2. It is transformed back into gravitational potential energy.
  3. The energy goes to producing sound and to heating the ground, rock and surrounding air.
  4. The energy goes into the ground and, as a result, the orbit of Earth about the Sun is slightly changed.
  5. The rock keeps the energy inside it (saving it for later use)


  1. while falling from a roof
  2. while parachuting from an airplane (parachute open)
  3. while accelerating downward in an elevator
  4. while walking on the Moon
  5. None of the above


  1. measuring the orbital period and distance of one of Jupiter's moons. (check properly this is the correct answer)
  2. measuring the orbital period and distance of Jupiter's orbit around the Sun.
  3. measuring the orbital speed of one of Jupiter's moons.
  4. knowing the Sun's mass and measuring how Jupiter's speed changes during its elliptical orbit around the Sun.
  5. knowing the Sun's mass and measuring the average distance of Jupiter from the Sun.


  1. you will not be able to see these two stars at all
  2. the two stars will appear to be touching, looking rather like a small dumbbell.
  3. you will see only the larger of the two stars, not the smaller one.
  4. the two stars will look like a single point of light,
  5. you will see two distinct stars


  1. Light pollution refers to the lights that must be used inside major observations and that make it difficult for astronomers' eyes to adapt to darkness
  2. Light pollution refers to pollution caused by light industry as opposed to heavy industry
  3. Light pollution is another name for sunlight, which makes it impossible to see stars in the daytime
  4. Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations


  1. size and distance similar to terrestrial planets; gaseous surface and composition similar to jovian planets
  2. size and solid surface similar to terrestrial planets; distance and density similar to jovian planets
  3. size and density similar to terrestrial planets; distance and composition similar to jovian planets
  4. solid surface and temperature similar to terrestrial planets; distance and density similar to jovian planets
  5. solid surface and density similar to terrestrial planets; temperature and composition similar to jovian planets


  1. Asteroids are rocky bodies and are denser than the comets, which are made of icy material.
  2. Asteroids and comets are both made of rocky and icy material, but asteroids are smaller in size than comets.
  3. Asteroids are rocky bodies and are less dense than the comets, which are made of icy material.
  4. Asteroids are made of icy material and are denser than the comets, which are more rocky.
  5. Asteroids are made of icy material and are less dense than the comets, which are rockier.


  1. the region around a star where liquid water can exist on planetary surfaces
  2. the region around a star where life exists
  3. the region around a star where humans can survive
  4. the region around a star where rocky planets form
  5. the region around a star where the ultraviolet radiation does not destroy organisms on a planetary surface


  1. The distance between Pluto and the Sun is always greater than that between Neptune and the Sun
  2. Stratosphere is part of the atmosphere that absorb ultraviolet
  3. Dark matter is purely hypothetical, because we have no way of detecting its presence
  4. The helium fusion process works by fusing two helium nuclei into one beryllium nucleus
  5. It is possible to see all constellations from the earth's equator


  1. K and M stars
  2. Open clusters
  3. O and B stars
  4. Gas and dust
  5. All of the above


  1. All stars spend approximately the same amount of time on the main sequence
  2. The heaviest element produced by massive stars is silicon
  3. The more distant a star, the smaller its parallax
  4. All stars have a core temperature of 1,000k


  1. Open galaxies
  2. Regular galaxies
  3. Globular galaxies
  4. Halo galaxies
  5. Elliptical galaxies


  1. The gradual disappearance of a crater rim as a result of wind and rain is not an example of tectonics quiz answer
  2. The fact that the sky is dark at night shows that the observable universe cannot extend forever
  3. Jupiter does not have seasons because it has no appreciable axis tilt wiki answer
  4. some stars are cool enough to have molecules in their atmosphere astro article
  5. There is no gravity in space


  1. Upper right
  2. Upper left
  3. Lower right
  4. Lower left
  5. Middle of the sequence


  1. Angular momentum of an object depends on its force, velocity and radius L = r x mv
  2. All pulsars are neutron stars, but not all neutron stars are pulsars
  3. A lunar eclipse occurs only when the Moon is new
  4. A lenticular galaxy is another name for an elongated elliptical galaxy
  5. Massive-star supernovae and white-dwarf supernovae work equally well as standard candles for measuring cosmic distances


  1. Velocity and distance
  2. Luminosity and distance
  3. Age and temperature
  4. Age and distance
  5. Luminosity and temperature


  1. Neutron degeneracy pressure
  2. Electron degeneracy pressure
  3. Radiation pressure
  4. Thermal pressure
  5. Proton degeneracy pressure


  1. The escape velocity from earth is greater for larger rocket than for small ones so that small rocket is preferred to use in space travel
  2. Nuclear power plants on Earth create energy in the same way as the Sun
  3. Mars have more extreme seasons than Earth because it has a more eccentric orbit
  4. The Big Bang predicts that one in four atoms in the universe is helium
  5. All stars including the Sun never move on the celestial sphere


  1. The outer layers of the star are no longer gravitationally attracted to the core.
  2. Hydrogen fusion in a shell outside the core generates enough thermal pressure to push the upper layers outward.
  3. Helium fusion in the core generates enough thermal pressure to push the upper layers outward.
  4. Helium fusion in a shell outside the core generates enough thermal pressure to push the upper layers outward.
  5. The internal radiation generated by the hydrogen fusion in the core has heated the outer layers enough that they can expand after the star is no longer fusing hydrogen.


  1. A standard candle is a form of dark matter
  2. A standard candle is an object for which we can easily measure the apparent brightness
  3. A standard candle is an object for which we are likely to know the true luminosity'
  4. A standard candle is a long, tapered candle that lights easily in space
  5. A standard candle is any star for which we know the apparent brightness


  1. gravitational contraction of the Sun
  2. wave motions in the solar interior
  3. variations of the solar thermostat
  4. the winding of magnetic field lines due to differential rotation
  5. hydrogen fusion in a shell outside the core of the Sun


  1. The corona and chromosphere are hotter than the photosphere
  2. Our Sun is considered a low-mass star
  3. If the university is accelerating, it will expand forever
  4. When energy is converted from one form to another, a tiny amount is inevitably lost
  5. Coma is a dirty snowball


  1. nuclear force, electromagnetic force, gravity, tidal force.
  2. strong force, weak force, electromagnetic force, gravity. check properly this is the correct answer
  3. nuclear force, gravity, electric force, magnetic force.
  4. strong force, weak force, electric force, magnetic force.
  5. strong force, weak force, electric force, dark force.


  1. nuclear fusion within the cores of high-mass stars.
  2. the bombardment of comets in the late stages of planet formation.
  3. white dwarfs.
  4. the Big Bang, when the universe first began.
  5. nuclear fusion within the cores of low-mass stars.


  1. redder and rounder.
  2. bluer and rounder.
  3. bluer and flattened.
  4. redder and flattened.
  5. always much smaller.


  1. In any star cluster, stars with lower masses greatly outnumber those with higher masses
  2. The time between rising and setting of a star is dependent on the observer's longitude
  3. Our Earth feels a greater tidal force from the Sun than from the Moon as the Sun has greater gravitational force
  4. The Coriolis effect is very important to the weather of Venus
  5. There is no limit to the mass with which a star can be born


  1. We do not yet have a theory that links quantum mechanics and general relativity.
  2. We do not know how hot or dense the universe was during that time.
  3. We do not understand the properties of antimatter.
  4. The Planck era was the time before the Big Bang, and we cannot describe what happened before that instant.
  5. We do not know how much energy existed during that time


  1. According to nebular theory, Oort cloud was made of material left over from the interstellar cloud that never contracted with rest of the gases to form the solar nebula false(quiz answer)THIS IS WRONG
  2. Copernicus had developed a system for predicting planetary positions that remained in use for 1,500 years false, it's Ptolemy (quiz answer)
  3. Our Earth is made mostly of metals and rocks and this material was made by our Sun [Our Earth is made mostly of metals and rocks and this material was made by our Sun false(yahoo answer)]
  4. The higher the magnification, the better the telescopes to observe depth sky objects
  5. Brown dwarfs white dwarfs and neutrons stars are all kept from collapsing by degeneracy pressure [1] TRUE
  1. when a star becomes luminous enough to emit thermal radiation
  2. the instant when hydrogen fusion first begins in the star's core
  3. when hydrogen fusion is occurring throughout a star's interior
  4. when the protostar assembles from a molecular cloud
  5. when the rate of hydrogen fusion within the star's core is high enough to sustain gravitational equilibrium


  1. radar ranging
  2. Hubble's law
  3. main-sequence fitting
  4. using Cepheid variables
  5. stellar parallax


  1. All stars in the cluster have approximately the same mass.
  2. Most of the stars in the cluster are younger than 10 billion years old.
  3. All stars in the cluster are approximately at the same stage in evolution.
  4. There is an approximately equal number of all types of stars in the cluster.
  5. Most stars in the cluster are yellow or reddish in color.


  1. Our Sun will likely undergo a nova event in about 5 thousand years
  2. If the distance between us and a star is doubled, its luminosity is decreased by a factor of four, but the apparent brightness remains the same false (wiki answer)
  3. Nitrogen and Ammonia are the main constituents of the jovian planets false, it's hydrogen and helium (quiz answer)
  4. Earth's atmosphere resulted from the impact of icy planetesimal that originated in the outer regions of the Solar System true(quiz answer)
  5. Most of the mass of the galaxy is located in the galactic center, in the form of a low-mass black hole


  1. do not have to be around the galactic center.
  2. are elliptical, with random orientation.
  3. do not have to pass through the plane of the galaxy.
  4. are elliptical but orbiting in the same direction.
  5. are relatively uniform to each other.


  1. Always a white dwarf
  2. Always a neutron star
  3. Either a white dwarf or a neutron star
  4. Either a neutron star or a black hole
  5. Always a black hole


  1. When travelling north from Singapore to China, you will see the North Star (Polaris) getting higher in the sky true(yahoo answer)
  2. Europa is considered likely to have a deep, subsurface ocean of liquid water true(quiz answer)
  3. When a returning space shuttle enters the atmosphere and begins to slow down, its kinetic energy is primarily converted into potential energy false, it's thermal energy
  4. Our Sun will end its life in a planetary nebula and become a white dwarf
  5. Pluto has more in common with comets in the Kuiper belt than it does with the other planets of the outer solar system


  1. ellipticals only
  2. irregulars only
  3. spirals only
  4. lenticulars only
  5. spirals and lenticulars


  1. on average, each solar mass of matter in the galaxy emits less light than our Sun.
  2. on average, each solar mass of matter in the galaxy emits more light than our Sun.
  3. the galaxy is not very massive.
  4. the galaxy is very massive.
  5. most stars in the galaxy are more massive than our Sun


  1. He found that the universe is expanding, and therefore concluded that Andromeda must lie outside our own galaxy.
  2. He was able to measure the parallax of the Andromeda Galaxy.
  3. By observing individual Cepheid variable stars in Andromeda and applying the period--luminosity relation.
  4. He was the first person ever to look through a telescope at the object we now call the Andromeda Galaxy.
  5. He found a massive star supernova in the Andromeda Galaxy


  1. Spiral galaxy rotation curves are generally flat out to large distances
  2. The Earth in our solar system has the strongest magnetic field false, it's the collisions between neutron stars (astro article)
  3. The cores of the terrestrial worlds are made mostly of metal because the terrestrial worlds as a whole are made mostly of metal. false(quiz answer)
  4. Nothing is left behind after a star goes supernova false(astro article)
  5. The Sun is located at the edge of the galaxy, appropriately 10 light-years from the galactic centre false(quiz answer)
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