Don’t Miss Tonight’s Spectacular Moon Event: How to Spot the Mysterious ‘X’ Marking!

Tonight, look up at the moon to spot something special: the Lunar X! This fascinating optical illusion will be visible from the US and Canada, with the best views between 6 PM and 8:20 PM ET.

The Lunar X appears at the terminator line, which is the edge between the moon’s light and dark sides. This happens during the moon’s first quarter phase when it’s 50% lit by the sun. The interplay of light and shadow creates striking shapes, making craters and mountains stand out beautifully.

To find the X, focus near the terminator, halfway between the moon’s equator and its south pole. It lies just northwest of the crater Werner, a prominent feature on the lunar surface. For the clearest view, grab some binoculars or a small telescope—though one could catch a glimpse with the naked eye under perfect conditions, binoculars will enhance the experience.

As the sunlight creeps across the moon’s surface, the shadowed areas cast long shadows, making features appear more dramatic. You’ll notice that the X takes shape as the sun rises over ridges near the craters La Caille, Blanchinus, and Purbach. This creates a unique optical display that looks different from when the sun is higher in the sky.

Before viewing, find a place away from bright lights so your eyes can adjust to the darkness. A spot with a clear line of sight will help you spot the X more easily.

If you’re curious about the other lunar feature, scan the sky northward along the terminator line to find the lunar V, which is just south of Mare Vaporum. It’s slightly larger than the X and creates a similar magical illusion at lunar dawn.

If you miss it tonight, don’t worry! The Lunar X and V appear once a month, but visibility may be limited. You can look forward to the next chances on May 4 and July 2, so mark your calendar!