Galilean Moons Lecture Notes

Flashcards about Galilean Moons

Galilean Moons

The four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto.

Copernican (heliocentric) model

Galileo's observation that the moons orbit around Jupiter provided support for this model.

Accretion disk origin of Galilean moons

Evidence for this theory includes the moons moving in nearly circular orbits in the equatorial plane of Jupiter, in the same direction that Jupiter spins.

Cause of orbital resonances of bodies

Regular, periodic gravitational pulling on the bodies as they pass near each other.

Tidally locked moons

Moons have rotation periods that are the same as their orbital periods.

Tidal flexing

A source of internal thermal energy for the three inner moons, due to tidal forces from Jupiter.

Galileo (orbiter spacecraft, 1989 - 2003)

Mission: Study Jupiter and its moons. First spacecraft to visit an asteroid.

New Horizons (flyby space probe) primary mission

Help understand worlds at the edge of our solar system by making the first reconnaissance of the dwarf planet Pluto and by venturing deeper into the distant, mysterious Kuiper Belt.

Multi-layer insulation (MLI)

Its main purpose is to prevent heat loss from radiation into space. It also helps protect spacecraft close to the Sun from overheating. A secondary role is to act as a shield against micrometeorites and dust.

Volcanism on Io

Convection within the mantle, driven by the temperature difference between the interior and surface, results in this.

Io

Volcanically more active than Earth, with colors on its surface resulting a result of sulfur compounds being expelled from its interior.

Internal energy source of Io

Subject to large tidal forces due to Jupiter’s large mass. Differences in gravitational pull create tidal flexing that generates thermal energy.

Albedo

The fraction of incident light that is reflected from a surface.

Europa's surface

High reflectivity, lack of impact craters, and cracks suggest:

Cryovolcanism

Low-temperature volcanism in which the magmas are composed of molten ices rather than rocky material.

Ganymede

Largest satellite (moon) in the solar system and only moon in the solar system to have a global magnetic field.

Callisto

Has an ancient, heavily cratered and unaltered ice surface.

Callisto's surface

Uniformly cratered, not uniform in color or brightness. Brighter areas = ice, darker areas = eroded ice-poor material.