The Outer Planets

Vocabulary flashcards covering the key terms, features, and celestial bodies of the outer planets: Jupiter, Saturn, Uranus, and Neptune.

Gas Giants

The name given to the first four outer planets—Jupiter, Saturn, Uranus, and Neptune—which are much larger and more massive than Earth, lack solid surfaces, and are composed primarily of hydrogen and helium.

Ring

A thin disc of small particles of ice and rock that surrounds a gas giant planet.

Jupiter

The largest and most massive planet in the solar system, featuring a thick atmosphere of hydrogen and helium, a liquid hydrogen and helium mantle, and a dense core of rock and iron.

Great Red Spot

A massive storm on Jupiter's surface that is larger than Earth, characterized by swirling winds, made up of hydrogen and helium

Jupiter’s 4 large moons

Io, Europa, Ganymede, and Callisto

Saturn

The second largest planet in the solar system, surrounded by broad, thin rings of ice and rock and possessing a thick atmosphere primarily composed of hydrogen and helium.

Titan

Saturn's largest moon, which is larger than the planet Mercury.

Uranus

An outer planet about $4$ times the diameter of Earth that rotates in about $17\text{ hours}$ on an axis tilted at approximately $90^\text{ degrees}$ from the vertical, surrounded by thin, dark rings.

Neptune

A cold, blue outer planet that is thought to be slowly shrinking and heating up internally, which produces visible clouds and storms in its atmosphere.

Great Dark Spot

A storm system on Neptune, similar to Jupiter's Great Red Spot, that did not last very long.

Triton

Neptune's largest moon, which features a thin atmosphere and a region near its south pole covered by nitrogen ice.