The Solar System - Dwarf Planets, Meteors & Asteroids

Vocabulary flashcards covering key terms about the Solar System, planet classifications, dwarf planets, and stars as described in the lecture notes.

Solar System

The Sun plus all planets and other celestial bodies that orbit the Sun; everything orbits the Sun in an anticlockwise direction.

Planet

A body that orbits the Sun directly (not a satellite of a planet); it is spherical and has cleared its orbital neighborhood, i.e., it is a dominant object.

Terrestrial planets (Inner planets)

Inner planets made of rock and metal; heavier and move slower; have no rings and very few moons; diameter less than 13,000 km.

Gas giant planets (Outer planets)

Outer planets made of gas, primarily hydrogen and helium; very large and move comparatively fast; have rings and many moons; diameter 48,000 km or less.

Dwarf planet

A body that meets the first two planet criteria but has not cleared its orbital neighborhood.

Pluto

A dwarf planet (one of the five known).

Eris

A dwarf planet.

Ceres

A dwarf planet.

Haumea

A dwarf planet.

Makemake

A dwarf planet.

Stars

Massive regions of burning hydrogen gas where nuclear fusion occurs.

Sun

The star at the center of the Solar System; energy produced by nuclear fusion of hydrogen; distance to Earth about 150 million km; light takes ~8.5 minutes to reach Earth.

Nuclear fusion

The process by which hydrogen atoms fuse to form helium, releasing energy; powers stars.