Astronomy

Solar System

"The Sun and all celestial objects orbiting it due to its gravitational influence."

Planet

"A celestial body that orbits the Sun”

Moon

"A natural satellite orbiting a planet."

Dwarf planet

"A celestial body orbiting the Sun that is spherical but has not cleared its orbital neighborhood of other debris."

Asteroid

"Small rocky or metallic object orbiting the Sun”

Comet

"A small celestial object composed of stony material, dust, and ice”

Weight

"The force exerted on an object due to gravity”

Orbit

"The path of a celestial object (planet, moon, satellite) as it revolves around another celestial body under the influence of gravity."

Centripetal force

"The force directed toward the center of a circular path that keeps an object moving in a circular orbit."

Ptolemy

"An ancient astronomer who proposed an Earth-centered model of the Solar System."

Copernicus

"Astronomer who proposed a heliocentric model placing the Sun at the center of the Solar System."

Gravitational field strength

"The force exerted by gravity on a unit mass at a point in space."

Red shift

"The phenomenon where light from distant galaxies appears shifted towards longer (redder) wavelengths due to the expansion of the universe."

Big Bang Theory

"The prevailing cosmological model explaining the origin and evolution of the universe approximately 13.8 billion years ago from a hot, dense state."

Cosmic Microwave Background Radiation (CMBR)

"The thermal radiation left over from the Big Bang, observable in all directions in the universe, supporting the Big Bang theory."

Steady State Theory

"An alternative cosmological theory positing that the universe has always existed in a constant state, but largely discredited due to CMBR evidence."

Observable Universe

"The portion of the universe visible from Earth, expanding over time with advances in observational technology."

Telescopes

"Instruments used to observe celestial objects, allowing for detailed study of distant stars, galaxies, and other phenomena."

Hubble Space Telescope

"A space telescope orbiting Earth since 1990, equipped to observe visible, infrared, and ultraviolet wavelengths."

Solar System

"The Sun and all celestial bodies orbiting it, including planets, moons, asteroids, and comets."

Nebula

"A cloud of gas and dust in space where stars are born."

Protostar

"A developing star formed from the gravitational collapse of a nebula, heating up until nuclear fusion ignites."

Main Sequence Star

"A stable phase in the life cycle of a star, including our Sun, where hydrogen fusion in the core balances gravitational collapse."

Red Giant Star

"A large, luminous star formed when a main sequence star depletes its hydrogen fuel and begins to fuse heavier elements."

White Dwarf

"The remnant core of a low to medium mass star after it has exhausted its nuclear fuel, gradually cooling over billions of years."

Supernova

"The explosive death of a massive star, releasing an enormous amount of energy and leaving behind either a neutron star or black hole."

Neutron Star

"A dense remnant of a supernova explosion primarily composed of neutrons."

Black Hole

"An object with gravitational pull so strong that nothing, not even light, can escape from it beyond a certain boundary."