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OpenStem
@openstem · Joined Jul 2026
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Quiz4 questions
What is the main difference between an asteroid and a comet?
AAsteroids are rock and metal; comets are ice, dust, and rockBAsteroids orbit the Sun; comets do notCComets are always bigger than asteroidsDThere is no real difference
Astronomy · L2 · Comets, Asteroids, and Meteoroids
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Astronomy · L2 · Comets, Asteroids, and MeteoroidsQuiz4 questions
What type of galaxy is the Milky Way?
AAn elliptical galaxyBA barred spiral galaxyCAn irregular galaxyDA dwarf galaxy
Astronomy · L2 · The Milky Way and Other Galaxies
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Astronomy · L2 · The Milky Way and Other GalaxiesQuiz4 questions
Where does nuclear fusion occur inside the Sun?
AThe coronaBThe photosphereCThe coreDThe convective zone
Astronomy · L2 · The Sun's Structure and Activity
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Astronomy · L2 · The Sun's Structure and ActivityQuiz4 questions
What was Sputnik 1?
AThe first human spaceflightBThe first artificial satellite, launched by the USSRCThe first Moon landingDThe first American space station
Astronomy · L2 · The Space Race
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Astronomy · L2 · The Space RaceQuiz4 questions
Since when has the International Space Station been continuously crewed?
A1969B2000C2021D1957
Astronomy · L2 · Modern Space Missions and Rovers
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Astronomy · L2 · Modern Space Missions and RoversQuiz4 questions
What is an exoplanet?
AA moon of a planet in our solar systemBA planet orbiting a star other than the SunCA planet with no star at allDAny object beyond Neptune
Astronomy · L2 · Exoplanets
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Astronomy · L2 · ExoplanetsQuiz4 questions
What is the main cause of ocean tides on Earth?
AWind blowing across the ocean surfaceBThe Moon's gravity pulling on Earth's oceansCEarth's rotation alone, with no outside influenceDOcean currents changing temperature
Astronomy · L2 · Tides and the Moon's Pull
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Astronomy · L2 · Tides and the Moon's PullQuiz4 questions
What is the celestial sphere?
AA real physical sphere surrounding EarthBAn imaginary sphere used to map star positions as seen from EarthCThe Sun's outer atmosphereDAnother name for the Milky Way
Astronomy · L2 · Navigating the Night Sky
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Astronomy · L2 · Navigating the Night SkyQuiz4 questions
What is a Near-Earth Object (NEO)?
AAny object inside the asteroid beltBAn asteroid or comet whose orbit brings it close to Earth's orbitCA satellite orbiting EarthDA comet that has already impacted Earth
Astronomy · L2 · Near-Earth Objects and Impact Risk
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Astronomy · L2 · Near-Earth Objects and Impact RiskQuiz4 questions
What is the solar wind?
AA stream of charged particles flowing out from the SunBA type of storm in Earth's atmosphereCWind caused by Earth's rotationDLight emitted by the Sun's core
Astronomy · L2 · Auroras and Earth's Magnetosphere
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Astronomy · L2 · Auroras and Earth's MagnetosphereQuiz4 questions
What best describes Low Earth Orbit (LEO)?
AVery high altitude with a 24-hour periodBLow altitude, roughly 90-minute orbital periodCAn orbit only around the MoonDAn orbit that never moves relative to the stars
Astronomy · L2 · Satellite Orbits and GPS
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Astronomy · L2 · Satellite Orbits and GPSQuiz4 questions
Why must radio telescope dishes usually be much larger than optical telescope mirrors?
ARadio waves are dimmer than visible lightBRadio wavelengths are much longer, requiring more collecting area for resolution and sensitivityCRadio telescopes only work at nightDRadio waves travel slower than visible light
Astronomy · L2 · Radio Astronomy Basics
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Astronomy · L2 · Radio Astronomy BasicsQuiz4 questions
What did the geocentric model claim?
AThe Sun is at the center of the universeBEarth is at the center, with everything else orbiting itCThe Moon is at the center of the solar systemDThere is no center to the universe
Astronomy · L2 · The Copernican Revolution
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Astronomy · L2 · The Copernican RevolutionQuiz4 questions
Why is Mars known as the 'Red Planet'?
AIt is covered in iron oxide (rust) dustBIt reflects red light from the SunCIts atmosphere is made of red gasDIt is the closest planet to the Sun
Astronomy · L2 · Mars in Depth
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Astronomy · L2 · Mars in DepthQuiz5 questions
Venus, Earth, and Mars formed in roughly the same region of the solar system from similar materials. What does comparative planetology try to explain?
AWhy they ended up so different despite similar starting pointsBWhy all three planets are actually identicalCHow many moons each planet hasDThe exact order the planets formed in
Astronomy · L2 · Comparative Planetology
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Astronomy · L2 · Comparative PlanetologyQuiz4 questions
What is a star cluster?
AA group of stars that formed together and are held together by gravityBAny two stars that happen to appear close together from EarthCA single star that is unusually brightDA cluster of planets orbiting one star
Astronomy · L2 · Star Clusters
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Astronomy · L2 · Star ClustersQuiz4 questions
What is light pollution?
AExcessive or poorly directed artificial light that brightens the night skyBSmoke and smog produced by streetlightsCNatural moonlight that outshines the starsDA type of radio interference affecting telescopes
Astronomy · L2 · Light Pollution and Dark Skies
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Astronomy · L2 · Light Pollution and Dark SkiesQuiz6 questions
Where do stars form?
AInside planetsBInside giant clouds of gas and dust called nebulaeCAt the edges of black holesDInside other stars
Astronomy · L2 · The Life Cycle of Stars Quiz
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Astronomy · L2 · The Life Cycle of Stars QuizQuiz6 questions
What is the nebular hypothesis?
AThe idea that planets were captured one by one from other systemsBThe idea that the Sun and planets formed together from one collapsing cloudCThe idea that the Sun formed before the galaxyDThe idea that planets formed from asteroid collisions only
Astronomy · L2 · How the Solar System Formed Quiz
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Astronomy · L2 · How the Solar System Formed QuizQuiz6 questions
Why do astronomers launch telescopes into space?
ATo make them cheaper to buildBTo avoid the atmosphere's blur and blocked wavelengthsCBecause space telescopes are easier to repairDTo get closer to the stars
Astronomy · L2 · Space Telescopes Quiz
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Astronomy · L2 · Space Telescopes QuizQuiz6 questions
What is the umbra?
AThe fully dark part of a shadowBThe partially lit part of a shadowCThe bright ring around an eclipseDAnother name for the Moon
Astronomy · L2 · Eclipse Mechanics Quiz
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Astronomy · L2 · Eclipse Mechanics QuizQuiz6 questions
Where is the asteroid belt located?
ABeyond NeptuneBBetween Mars and JupiterCBetween Earth and MarsDAround the Sun's poles
Astronomy · L2 · The Asteroid Belt and Kuiper Belt Quiz
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Astronomy · L2 · The Asteroid Belt and Kuiper Belt QuizQuiz5 questions
According to Kepler's First Law, where is the Sun located relative to a planet's elliptical orbit?
AAt the exact centre of the ellipseBAt one of the two fociCOutside the ellipse entirelyDAt the point farthest from the planet
Astronomy · L3 · Kepler's Laws & Orbital Mechanics
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Astronomy · L3 · Kepler's Laws & Orbital MechanicsQuiz5 questions
If the distance between two masses triples, what happens to the gravitational force between them?
AIt triplesBIt drops to a thirdCIt drops to a ninthDIt stays the same
Astronomy · L3 · Newtonian Gravitation
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Astronomy · L3 · Newtonian GravitationQuiz5 questions
In the OBAFGKM sequence, which class of star is the hottest?
AMBGCODK
Astronomy · L3 · Stellar Classification
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Astronomy · L3 · Stellar ClassificationQuiz5 questions
What must happen inside a protostar for it to become a true main-sequence star?
AIts outer layers must cool completelyBIts core must reach about 10 million K and ignite sustained hydrogen fusionCIt must collide with another protostarDIt must lose most of its mass
Astronomy · L3 · Stellar Evolution
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Astronomy · L3 · Stellar EvolutionQuiz5 questions
What does it mean to say 'space itself is expanding,' as opposed to 'galaxies are moving through a fixed space'?
AGalaxies are physically flying apart at high speed under their own enginesBThe space between galaxies is stretching, carrying them apart much like dots on an inflating balloonCNothing is actually moving; it is an optical illusionDGalaxies are falling into a central point
Astronomy · L3 · The Big Bang & Cosmology
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Astronomy · L3 · The Big Bang & CosmologyQuiz5 questions
What does a flat galaxy rotation curve suggest?
AThe galaxy has less mass than it appears toBThere is more unseen mass than the visible matter alone accounts forCNewtonian gravity is completely wrongDThe galaxy is not actually rotating
Astronomy · L3 · Dark Matter & Dark Energy
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Astronomy · L3 · Dark Matter & Dark EnergyQuiz5 questions
What are the three main galaxy shapes in the Hubble sequence?
ASpiral, elliptical, and irregularBSmall, medium, and largeCRed, blue, and yellowDNear, far, and distant
Astronomy · L3 · Galaxy Types & the Milky Way
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Astronomy · L3 · Galaxy Types & the Milky WayQuiz5 questions
What does a periodic dip in a star's measured brightness usually indicate?
AThe star is about to explodeBA planet is transiting in front of the starCThe telescope has malfunctionedDThe star has stopped fusing hydrogen
Astronomy · L3 · Exoplanet Detection
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Astronomy · L3 · Exoplanet Detection