A trick of the light will cause a vast letter "X" and "V" to appear on the lunar surface tonight, mere hours before the moon hits its first quarter phase, which will see its right half lit by direct sunlight and its left veiled in darkness.
The moon's position relative to the sun changes constantly throughout its 27-day orbit of Earth, throwing countless craters, mountain ranges and myriad other geographical features into focus as the line separating night from day known as the "terminator" sweeps across its surface.
