Moon

The Moon is a natural satellite in orbit around Remnant.

Apart from being a striking visual feature of the series, it may also bear some symbolic significance.

Appearance
The most obvious feature of the satellite moon is it does not appear to be uniformly spherical like traditional moons, but instead appears to be partially "shattered". While most of Remnant's moon remains predominantly spherical, a large portion has been dislodged, broken and displaced into several floating, irregularly-formed fragments held within the moon's gravity. It is still unknown what caused the moon to exist in this unusual shape.

Astrophysics


Remnant's moon follows a peculiar lunar cycle radically different to that of Earth's. Unlike Earth's moon, which is tidally locked to Earth and thus always presents the same surface when viewed from the planet's surface, Remnant's moon exhibits an asynchronous rotation in spin-orbit resonance. In other words, the rotation period of the moon's axis rotation differs from the orbital period of its orbital rotation around Remnant.

As a result of this, at different points in the lunar cycle, the moon presents a different face to the planet: when the hemispherical fragment is directly facing Remnant, the moon appears full; at other times the moon's fragments are visible.

Different phases of the lunar cycle are visible throughout the series. For example, in "Ruby Rose", the moon appears to be in a broken phase, while in "The Shining Beacon, Pt.2", it appears to be full.

It is not known what role illumination from the sun plays in this lunar cycle, though the surface of the moon facing Remnant does appear to be always fully illuminated. This may be due to a peculiarity of its orbit causing it to be fully lit when viewed from Remnant's surface. Another possibility is that the moon may actually provide its own light.

Symbolism




The moon is a significant recurring visual motif in the series. The writers of the show have stated that the moon's appearance is not arbitrary or coincidental. The moon is heavily associated with Ruby Rose, who appears dramatically silhouetted against the full moon in both the "Red" Trailer and the Volume 1 Opening, as well as on official merchandise.

Yang Xiao Long may also be symbolically connected to the sun in a similar way. The moon also makes a significant appearance in the "White" Trailer, as Weiss Schnee gazes up into the sky after her performance and sees the moon in its partially-shattered phase. The moon appears briefly in the "Black" Trailer, again in its shattered phase.

It is also notable that the moon in its cracked phase heralds two significant appearances of Roman Torchwick, first in "Ruby Rose", and later in "Players and Pieces". The moon in its cracked phase may foreshadow the unfolding plans of the villains of RWBY.

Reference to the moon is also made on several occasions in the RWBY: Volume 1 Soundtrack in the song "Gold:" "If the stars all fall / When there's no more light / and the moon should crumble / It will be alright," and again in the song "I May Fall:" "When we lose our faith / And forsake our friends / When the moon is gone / And we've reached our ends."

Specific reference to the moon being shattered is also made on the RWBY: Volume 2 Soundtrack songs "Die": "Our path was clear / The moon watched safely from above", "Enemies arise and the hate is flowing / Shattering the moon and bloodying the sky" and "Sacrifice": "The moon will sadly watch the roses die."

Trivia

 * Monty Oum has compared the moon of RWBY to the Praxis, the shattered moon of the Klingon homeworld in Star Trek.