space flashcards
The force that keeps planets in orbit around the Sun.
Gravity
The process that powers stars by fusing hydrogen into helium.
Nuclear fusion
The path a planet takes around the Sun.
Orbit
The nickname of Mars due to its reddish appearance.
The Red Planet
The two planets known as “ice giants.”
Uranus and Neptune
The event where the Moon moves into Earth’s shadow.
Lunar eclipse
The event where the Moon blocks sunlight from reaching Earth.
Solar eclipse
The phase of the Moon when it is completely illuminated.
Full moon
The term for a star that suddenly brightens due to an explosion.
Supernova
The force that pulls objects toward a planet’s surface.
Gravitational force
The reason astronauts feel weightless in space.
Free fall (microgravity)
The hottest type of star in terms of color.
Blue stars
The coldest type of star in terms of color.
Red stars
The reason the Moon has no atmosphere.
Weak gravity
The name for the outermost layer of the Sun’s atmosphere.
Corona
The effect where light shifts toward red when an object moves away in space.
Redshift
The region of space with a strong gravitational pull that nothing can escape.
Black hole
The explosion that creates elements heavier than iron in space.
Supernova
The point in a black hole where gravity is infinite.
Singularity
The reason why Mercury has extreme temperature differences.
No atmosphere
The largest volcano in the solar system, found on Mars.
Olympus Mons
The planet with the fastest rotation in the solar system.
Jupiter
The type of star our Sun will become at the end of its life.
White dwarf
The region around a planet where its gravity dominates over the Sun’s.
Hill sphere
The belt of icy objects beyond Neptune that includes Pluto.
Kuiper Belt
The cloud of comets surrounding the solar system, extending far into space.
Oort Cloud
The reason Venus is hotter than Mercury despite being farther from the Sun.
Greenhouse effect
The point in a planet’s orbit where it is closest to the Sun.
Perihelion
The point in a planet’s orbit where it is farthest from the Sun.
Aphelion
The boundary around a black hole beyond which nothing can escape.
Event horizon
The type of galaxy that the Milky Way is.
Spiral galaxy
The phenomenon where time slows down near a black hole.
Time dilation
The term for a rocky object that burns up in Earth’s atmosphere.
Meteor
The term for a rocky object that survives and hits Earth’s surface.
Meteorite
The reason the Moon always shows the same face to Earth.
Tidal locking
The force that causes tides on Earth.
Gravitational pull of the Moon
The name of the dark, flat plains on the Moon formed by lava flows.
Lunar maria
The second stage of a star’s life cycle after a nebula collapses.
Protostar
The name for a rapidly rotating neutron star that emits beams of radiation.
Pulsar
The nickname for Jupiter due to its role in protecting inner planets.
Cosmic vacuum cleaner
The theory that the universe is expanding from an initial explosion.
Big Bang Theory
The element that makes up most of Jupiter and Saturn.
Hydrogen
The name of Saturn’s largest moon, which has a thick atmosphere.
Titan
The reason the sky on Uranus appears blue-green.
Methane in the atmosphere
The name of the region where new stars are born.
Nebula
