Astronomy and Celestial Mechanics Vocabulary

Vocabulary flashcards generated from lecture notes covering planets, astronomical terms, coordinate systems, and stellar lifecycle concepts.

Rock

A solid material made of minerals, metals, and silica.

Minerals

Substances that are made of elements.

Jupiter

The largest planet in the Solar System, composed of gases.

Comet

A celestial object made of ice.

Isotope

An atom that has more neutrons than protons.

Zenith

The point directly above you in the sky.

Celestial Horizon

A circular boundary dividing the Earth and the sky.

Nadir

The point directly down below you.

Celestial Meridian

An imaginary line that divides the sky into two halves.

Polaris (Pole Star / North Star)

The last star in the Little Dipper, pointed to by the emptied Big Dipper.

Arcturus

A very bright, very old red star.

Corona Borealis

A constellation known as the Northern Crown.

Vega

A very young, blue star located in the constellation Lyra, which is the brightest star in the northern hemisphere when facing north.

Milky Way

A band of dust between us and the galactic core, spanning $100{,}000\text{ light years}$ across.

Orion Arm

The arm of stars in the Milky Way galaxy where Earth is located.

Light Year

The distance light travels in a single year.

Speed of Light

The speed at which light travels, equal to $186{,}000\text{ miles/sec}$ or $300{,}000\text{ km/sec}$.

Nebula

A cloud in space filled with hydrogen gas.

Supernova

An explosion of a super giant star causing energetic expansion, representing the most energetic event besides the Big Bang.

Black Hole

The leftover remnant remaining after a supernova explosion.

Nuclear Fusion

The process in which elements come together inside stars.