Chapter 16: Space Knowledge Organiser

Vocabulary flashcards based on the Space chapter knowledge organiser, detailing star life cycles, orbital mechanics, cosmic radiation, red-shift, and theories of the universe.

Solar System

The system consisting of the Sun (a star) and all the objects that orbit it, including eight planets, dwarf planets, moons (natural satellites), asteroids, and comets.

Milky Way Galaxy

The galaxy in which our Solar System is located, containing billions of other stars.

Nebula

A huge cloud of dust and gas from which stars are formed by gravitational attraction.

Protostar

A dense, collapsing cloud of gas and dust pulled together by gravity, which heats up as particles collide prior to the onset of nuclear fusion.

Main Sequence Star

A stable phase in a star's life cycle where outward forces from nuclear fusion reactions are in equilibrium with inward gravitational forces.

Life Cycle of a Star (Sun-sized Mass)

The sequence of changes for a star with about the same mass as the Sun: nebula ➞ protostar ➞ main sequence star ➞ red giant ➞ white dwarf ➞ black dwarf.

Life Cycle of a Star (Massive Star)

The sequence of changes for a star with much greater mass than the Sun: nebula ➞ protostar ➞ main sequence star ➞ red supergiant ➞ supernova ➞ neutron star or black hole.

Supernova

The explosion of a massive star (red supergiant) that produces elements heavier than iron and distributes elements throughout the universe.

Neutron Star

A dense remnant formed after a supernova explosion of a massive star, if the remaining mass is not high enough to form a black hole.

Black Hole

An extremely dense object formed after a supernova explosion of a star with exceptionally high mass.

Centripetal Force

The resultant force directed towards the centre of a circular orbit that keeps an object moving in a circle, provided by gravity for planets and satellites.

Circular Orbital Motion

Motion in a circular path where an object moves at a constant speed but constantly changes direction, meaning its velocity is constantly changing and it is constantly accelerating.

Stable Orbit Speed and Radius

The relationship in a stable orbit where changing an object's speed changes its orbital radius; a slower speed corresponds to a larger orbital radius.

Red-shift

The increase in the observed wavelengths of light from a source (such as a distant galaxy) that is moving away from the observer.

Big Bang Theory

The scientific theory proposing that the universe began from an extremely small, hot, and dense region that exploded and expanded.

Dark Energy

A theoretical concept proposed by scientists to explain the accelerating expansion of the universe.

Dark Matter

An unidentified form of matter thought to provide the gravitational force holding galaxies together.

Nuclear Fusion in Stars

The process in which light nuclei (such as hydrogen) fuse to form heavier nuclei (such as helium and heavier elements up to iron), releasing huge amounts of energy.