Space Physics: Stars, Satellites, and Cosmology

Vocabulary flashcards reviewing key astronomical terms, stellar evolution, circular orbital mechanics, red shift, and evidence for the Big Bang.

Asteroid belt

A region located between Mars and Jupiter containing orbiting rocky debris.

Milky Way

The galaxy in which our solar system is located.

Nebula

A cloud of dust and gas particles pulled together by gravity that becomes denser and hotter until nuclear fusion begins.

Main sequence stage

The stable period in a star's life cycle when the outward pressure from fusion and the inward gravitational force remain balanced.

Red giant

The expanded stage of a dying star of similar size to our sun, caused by an increase in outward pressure.

White dwarf

The dense core that remains when a red giant collapses after exhausting all of its fusion fuel.

Black dwarf

The cold remnant of a white dwarf after it has completely cooled down.

Super red giant

The expanded dying stage of a star that is much bigger than our sun.

Supernova

The powerful explosion of a super red giant that releases enough energy to fuse heavier elements and disperses material to form new nebulae.

Neutron star

A very dense body left at the center of an exploded super red giant.

Black hole

An extremely dense body formed after a supernova that is even denser than a neutron star.

Geostationary satellites

Circular-orbiting artificial satellites that stay above the same spot over the Equator with an orbital time period of $24\text{ hours}$, commonly used for communication.

Centripetal force

Any force that results in circular motion, which always acts towards the center of the orbit and perpendicular to the object's velocity.

Red shift

The lengthening of light wavelengths toward the red end of the spectrum observed from distant stars and galaxies, showing that they are moving away from us.

CMBR (Cosmic Microwave Background Radiation)

Microwave radiation detected from all directions across outer space, produced by matter still cooling down from the Big Bang.