Did You See This X on the Moon? Here’s Why It Was There

Did You See This X on the Moon? Here’s Why It Was There

On March 6, 2025, a giant “X” could be seen on the moon. Every so often, this rare event displays an optical illusion on the moon in the shape of a cross. That cross is called the “Lunar X” or “Werner X”. 

The phenomenon isn’t a mystery, nor is it new, but it still manages to capture the attention of astronomers and casual stargazers alike. The illusion is created when sunlight strikes the rims of three overlapping craters—Purbach, La Caille, and Blanchinus—casting shadows in such a way that the letter ‘X’ becomes visible. The effect doesn’t last long; the angle of the sunlight shifts, and the X fades into the Moon’s rugged landscape.

Last night, the phenomenon started at around 7:25 p.m. EST and became fully visible by 9:20 p.m., remaining clear for about an hour before slowly fading as the surrounding lunar landscape was further illuminated. The entire event lasted approximately four hours.

For those hoping to catch the Lunar X in the future, the key is to look along the moon’s terminator—the line dividing the illuminated and shadowed portions of the lunar surface. The X appears about halfway between the moon's equator and its south pole, just northwest of the Werner crater. Using a pair of binoculars or a small telescope provides the best view, though under perfect conditions, it may be hard to see to the naked eye.