Atom: The basic unit of matter, consisting of a nucleus of positively charged protons and neutral neutrons, surrounded by negatively charged electrons.
Asteroid: Small, rocky objects that orbit the Sun, primarily found in the asteroid belt located between Mars and Jupiter.
Astronaut: A person trained for traveling and working in space, often as a member of a spacecraft's crew.
Astronomical Unit: A unit of measurement used in astronomy to represent the average distance between the Earth and the Sun, approximately 149.6 million kilometers.
Astronomy: The scientific study of celestial objects, space, and the universe as a whole.
Big Bang: The prevailing cosmological model that describes the rapid expansion of the universe from an extremely high-density and high-temperature state.
Black Hole: A region in space where gravity is so strong that nothing, not even light, can escape from it. It forms from the remnants of massive stars.
Celestial Body: Any naturally occurring physical entity in space, such as stars, planets, moons, asteroids, and comets.
Comet: A celestial object composed mainly of ice, dust, and gas that orbits the Sun in an elongated, elliptical orbit.
Cosmonaut: A person trained for traveling and working in space, especially as a member of the Russian or former Soviet space program.
Cosmos: The universe seen as a well-ordered whole, often used to describe the entirety of space, time, and all that exists.
Cosmology: The scientific study of the large-scale properties of the universe as a whole, including its origin, evolution, and eventual fate.
Dark Energy: A mysterious form of energy that is thought to be responsible for the accelerated expansion of the universe.
Dark Matter: Non-luminous, invisible matter that is thought to make up a significant portion of the total mass in the universe.
Dwarf Planet: A type of celestial body that orbits the Sun and has sufficient mass for its self-gravity to overcome rigid body forces, but has not cleared its orbit of other debris.
Dwarf Star: A small or medium-sized star, such as a red dwarf, white dwarf, or brown dwarf, which are less massive and cooler than the Sun.
Galaxy: A large system of stars, star clusters, gas, dust, and dark matter bound together by gravity.
Galactic Supercluster: A vast group of galaxies and galaxy clusters bound together by gravity.
Galactic Web: The large-scale structure of the universe, consisting of interconnected filaments of galaxies and voids.
Geocentric View: An ancient cosmological model that places the Earth at the center of the universe, with celestial bodies orbiting around it.
Gravitational Wave: Ripples in space-time caused by the acceleration of massive objects, predicted by Einstein's theory of general relativity.
Gravity: The force of attraction between two masses, responsible for the phenomenon of weight and the motion of celestial bodies.
Heliocentric View: A cosmological model that places the Sun at the center of the solar system, with planets orbiting around it.
Helium: A chemical element, represented by the symbol He, that is a colorless, odorless, and inert gas, commonly found in the universe.
Hydrogen: The lightest and most abundant chemical element in the universe, represented by the symbol H.
Interstellar Space: The vast expanse of space that exists between stars within a galaxy.
Light Year: The distance that light travels in one year in the vacuum of space, approximately 9.46 trillion kilometers (5.88 trillion miles).
Matter: Any substance that has mass and occupies space, composed of atoms or subatomic particles.
Nebulae: Vast clouds of gas and dust in space, often the birthplaces of stars.
Neutrino: An extremely light, electrically neutral subatomic particle that is produced in various nuclear reactions.
Neuron: A specialized cell in the nervous system that transmits information through electrical and chemical signals.
Observatory: A facility equipped with telescopes and instruments for observing and studying celestial objects and phenomena.
Orbit: The curved path that an object follows around a celestial body due to gravitational attraction.
Planet: A celestial body that orbits a star, is spherical in shape, and has cleared its orbit of other debris.
Rotation: The spinning motion of a celestial body around its own axis.
Shooting Star: A common name for a meteor, which is a bright streak of light that occurs when a meteoroid enters the Earth's atmosphere and burns up due to friction.
Space Ship: A generic term for any manned or unmanned vehicle designed for travel or operation in outer space.
Space Shuttle: A reusable spacecraft designed for missions to transport astronauts and cargo to and from space.
Space-time: The interconnected four-dimensional framework of the universe, combining three dimensions of space with one dimension of time.
Star: A massive celestial body primarily composed of hydrogen and helium, undergoing nuclear fusion to emit light and heat.
Supernovae: A catastrophic explosion that occurs when a star reaches the end of its life cycle, resulting in a sudden increase in brightness.
Telescope: An optical instrument designed for viewing distant objects in space, gathering and magnifying light to enhance observation.
Universe: The entirety of space, time, matter, and energy, including galaxies, stars, planets, and all forms of cosmic structures.
Universe Expansion: The overall increase in the size and scale of the universe, first theorized as a consequence of the Big Bang.
Wavelength: The distance between successive peaks or troughs of a wave, such as electromagnetic radiation.
Universe Inflation: A rapid and exponential expansion of the universe believed to have occurred in the moments following the Big Bang.