Gas Giants and Satellite Systems

Vocabulary practice flashcards covering the physical characteristics, atmospheric dynamics, internal structures, missions, and major satellite systems of Jupiter and Saturn.

Jupiter and Saturn Composition

Composed primarily of hydrogen ($\text{H}$) and helium ($\text{He}$)—nearly the same composition as the Sun—with minor fractions of ice and rock.

Saturn's Interior Structure

A layered interior spanning a total radius of $60$ units, consisting of a central rock core ($0-8$), an ice layer ($8-16$), a metallic hydrogen mantle ($16-30$), and an outer molecular hydrogen envelope ($30-60$).

Saturn's Diameter

A planetary equatorial diameter of approximately $120{,}000\,\text{km}$.

Cassini-Huygens

The joint robotic spacecraft mission designed and deployed to explore Saturn, its ring system, and its moons.

Titan

Saturn's largest moon ($5150\,\text{km}$ across) and the only moon in the solar system with a thick atmosphere; it maintains a surface temperature of $92^\circ\text{K}$, a density between ice and rock, and an atmosphere consisting mostly of $\text{N}_2$.

Methane Photolysis (Titan)

The chemical decomposition of methane gas initiated by solar ultraviolet ($\text{UV}$) radiation in Titan's nitrogen-rich atmosphere, creating dense organic aerosol hazes that resemble smog.

Enceladus

An icy moon of Saturn exhibiting active cryovolcanic geysers that blast ice particles into space via warm vapor escaping through surface fissures, propelled by tidal heating.

Jupiter's Interior Structure

A layered planetary interior reaching a radius of $71$ units, composed of a rocky core ($0-7$), an ice core boundary ($7-14$), an extensive metallic hydrogen shell ($14-59$), and an upper layer of molecular hydrogen ($59-71$).

Jupiter's Diameter

A planetary diameter measuring approximately $142{,}000\,\text{km}$.

Galileo Mission

The NASA robotic space mission launched to orbit Jupiter and investigate the gas giant and its satellite system.

Io

The innermost large moon of Jupiter, characterized by a rocky composition and intense volcanic activity; it is roughly the size of Earth's Moon and larger than Pluto.

Europa

Jupiter's second large moon from the planet, comprising a rocky interior enclosed by a thin icy crust with a subsurface liquid ocean; it is approximately the size of Earth's Moon and larger than Pluto.

Ganymede

Jupiter's third large moon, composed of roughly equal parts rock and ice with a subsurface ocean; it is larger than Mercury and Pluto and is the only moon known to generate its own intrinsic magnetic field.

Callisto

The outermost of Jupiter's four large moons, made of roughly half rock and half ice, containing a subsurface ocean and exceeding Pluto in size.

Galilean Moons (Distance Sequence)

The four major moons of Jupiter ordered from closest to furthest: Io, Europa, Ganymede, and Callisto.

Synchronous Locking (Jupiter's Moons)

The dynamical state in which all four major moons of Jupiter (Io, Europa, Ganymede, and Callisto) complete one orbital revolution in the same time they rotate once, keeping the same hemisphere continuously facing Jupiter.