Jupiters Moons Flashcards
What are the main characteristics of Io?
No impact craters
Smooth young volcanic surface
Highest density but not the greatest size of the largest moons (3530 kg/m^3)
Active volcanic - caldera collapses common
Surface
No visible impact craters hence surface younger than 1my
Plumes from 8 active volcanoes - high resurface 10-100my
Many hundreds of calderas
Surface largely extensive with areas of frozen SO2
Fault scalps visible - a shard ridge (Mongibello Mons)
Deposition
Sulfur dioxide rich vapours from the plume frozen and then snowed out onto the ground (superheated and cause the eruption to be so violent also with low gravity and low atmospheric pressure)
Flat topped Mesa surrounding a caldera Scalloped margins (sharp) due to sapping (fluid/sulfur dioxide is pressurised and the escapes as gas removing ejecta. Sulfur dioxide the goes to frost, overlain, melts and repeats cycle)
What are the main characteristics of Europa?
Bright clean icy surface
Few impact craters
Active geological features
Surface - rigid
Scarcely cratered surface
Rigid plains and mottled terrain are the main landforms
Geologically active
Smooth plains - Ice water volcanoes flood low lying areas
Ridges plains - Opening and closing of fractures
Chaos - platy fracture and rotational crustal rock (due to diurnal stresses - reaches 1 bar ice breaks at 0.7 bar)
Ridges plains
Banded terrane - linear curved wedges with low albedo with bilateral symmetry (cusp & segment) AND fractures can be filled with upwelling surface
Ridged terrane - intersecting cracks at topographic high
Plumes - would form if liquid water breached surface
Europa interior
Metallic core - warm connecting ice - cold brittle surface
Metallic core - liquid ocean - ice covering
What are the main characteristics of Ganymede?
Complex surface with light and dark terraces
Abundant impact craters
Geological features
Largest of the moons (5212km)
Surface - cratered and ice
Tectonically active
Abundant cratering
Leading and trailing hemisphere have different characteristics
Leading - brownish grey in colour, heavily cratered, lighter tectonically deformed area
Trailing - low albedo, grooved and furrowed terrains
Ice caldera?
Scalloped margin - depression containing a lobate flow like feature that is the best candidate for an icy volcanic lava flow
What are the main characteristics of Callisto?
Low albedo meaning dark surface
Many impact craters
No geological features
Surface - cratered and heavily eroded/weathered
Very abundant impact craters
Covered by a dark material layers - this erodes and semi-covers small craters
Geologically dead
The flows on Io are they composed of silicate and sulfur and give reasons?
Sulfur evidence
Presence of S ions I’m Io’s plasma torus
Eruption temperate of volcanoes match melting point of sulfur
Low resolution spectra from UV-IR match sulfur SO2 allotropes
Why is Io so volcanically active?
Significant radiogenic decay if heat producing elements
Only 6 Jupiter radii away from Jupiter (strong tidal working - orbital and rotational energy dissipated as heat)
Source of internal heating
How does jupiters icey moons differentiate?
Undifferentiated body composed of rock and ice begins to warm up
Warm body approaches temperate of Ice I - (II)I melting minimum
Layer of ice and rock separate degassing volatiles
Icy surface develops dense rock layer forcing density to overturn
Creating a fully differentiated ice crust with rocky core
Closer to Jupiter more likely to occur (stronger tidal forces)
