Wiccan views of divinity the ancient Greek conception, where the elements correspond to matter (earth) and energy (fire), with the mediating elements (water, air) relating to the phases of matter (fire/earth mixtures). A more modern conception correlates the four elements to the four states of matter known to science: Solid (earth); Liquid (water); Gas (air); and Plasma (fire); with the akasha element corresponding to pure Energy. The Aristotelian system proposes a fifth or quintessential element, spirit (aether, akasha). The preferred version is a matter of ongoing dispute in the Wiccan community. There are other non-scientific conceptions, but they are not widely used among Wiccans.
Extraterrestrial liquid water combined with evidence of ongoing cryovalcanic activity. Scientists' consensus is that a layer of liquid water exists beneath Europa's surface, and that heat energy from tidal flexing allows the subsurface ocean to remain liquid. The first hints of a subsurface ocean came from theoretical considerations of tidal heating (a consequence of Europa's slightly eccentric orbit and orbital resonance with the other Galilean moons). Scientists used gravitational measurements from the Cassini spacecraft to confirm a water ocean under the crust of Enceladus. Such tidal models have been used as theories for water layers in other Solar System moons. According to at