Month: July 2025

CHEMICAL DIFFERENTIATION – The process where heavier elements settle toward the center of a forming planet while lighter materials remain on the outer layers.

HELIUM FLASH – The sudden onset of helium fusion in the core of a star during its formation, marking the end of its contraction phase.

SPIRAL GALAXY – A galaxy in which stars, gas, and dust are concentrated in spiral arms, often the type of galaxy that may be a site for solar system formation.

T-TAURI PHASE – The stage in the formation of a star during which it is still in a contraction phase and exhibits strong solar winds.

CORE ACCRETION MODEL – A model suggesting that planets form by the gradual accumulation of solid material, leading to the formation of a planetary core which then attracts a surrounding gas envelope.

PLANETESIMALS – Small, solid objects that formed from the accretion of dust and gas and eventually combined to form planets.

SOLAR NEBULA – The cloud of gas and dust from which the Sun and planets formed.

ACCRETION – The process by which dust and gas come together to form larger bodies, eventually leading to the formation of planets.

PROTOPLANETARY DISK – A rotating disk of dense gas and dust around a newly formed star, from which planets are formed.

NEBULAR HYPOTHESIS – A theory that suggests the solar system formed from the gravitational collapse of a giant molecular cloud, with the Sun forming at the center and planets forming from the surrounding material.