AI Insight
During the first quarter moon phase in May, two large optical phenomena resembling the letters "X" and "V" become visible on the lunar surface. These formations are created by the interplay of sunlight and shadow along the terminator line, the boundary between the illuminated and dark portions of the moon. The effect is produced by specific crater rims and mountain ridges catching sunlight at precise angles, making them appear as distinct letter-shaped features to observers on Earth.
Why it matters
These predictable lunar optical events provide accessible opportunities for amateur astronomers to engage with observational science using basic equipment such as binoculars or small telescopes. Understanding how light and shadow interact with lunar topography also contributes to broader knowledge of surface geometry and selenography.
Here’s when to see a pair of massive letters shining on the lunar surface around May’s first quarter moon phase.
Source: Massive 'X' and 'V' shapes will appear on the moon tonight — here's how to see them