A Rare Celestial Event: The Moon and Pleiades Eclipse
On Sunday, July 20, 2025, a rare and mesmerizing astronomical event will capture the attention of early risers across North America. The waning crescent moon, which will be just 24% illuminated, will pass directly in front of the Pleiades star cluster, also known as the Seven Sisters. This celestial alignment, referred to as an occultation or eclipse, offers skywatchers a unique opportunity to witness two of the most brilliant objects in the night sky seemingly collide. This extraordinary spectacle will be visible across the U.S., Canada, and Mexico—making it a must-see event for all astronomy enthusiasts.
What to Expect from the Moon and Pleiades Eclipse
The eclipse will begin between 2:00 a.m. EDT and 5:00 a.m. EDT, during which the moon will appear to move in front of the Pleiades star cluster. As the moon passes in front of the cluster, it will briefly block out the brightest stars, including Alcyone, the brightest star in the group. After a few moments, these stars will reappear, and the moon will continue on its path. This alignment is not just a fascinating visual display but also a line-of-sight illusion. The moon is only about 226,000 miles away, while the Pleiades is located a staggering 445 light years from Earth. The contrast in distances adds a profound perspective to this beautiful celestial event. The apparent proximity of the two objects in the sky highlights the vastness of space.
Timing Your Observation: When and Where to Look
If you want to catch this incredible sight, you’ll need to be outside between 2:00 a.m. EDT and 5:00 a.m. EDT on July 20. The moon and the Pleiades will rise in the east-northeast and remain visible until dawn breaks. Observers are encouraged to be outside by 3:00 a.m. EDT, when the moon will be passing directly in front of the brightest stars of the cluster. After 3:00 a.m., you’ll also be able to spot Venus rising below the pair, adding another celestial object to the skywatching experience. The alignment is a stunning moment where the moon and Pleiades briefly come together in a cosmic dance before the night gives way to daylight.
The Science Behind the Event: A Cosmic Line of Sight Illusion
While the moon-Pleiades eclipse is an awe-inspiring visual, it’s important to understand that it’s an optical illusion. The moon is positioned much closer to Earth at 226,000 miles, whereas the Pleiades star cluster lies a vast 445 light years away. Light from the moon takes just 1.3 seconds to reach us, whereas the light from the Pleiades takes a staggering 445 years to travel across space. This immense difference in distance creates a captivating illusion where two celestial objects appear to be in the same location, when in reality, they are separated by an enormous gap. This phenomenon is a perfect reminder of the scale of the universe we live in.
How to View the Eclipse: A Skywatcher’s Guide
To make the most of this event, all you need is a clear view of the east-northeast horizon. No special equipment is necessary to witness the eclipse, although binoculars can enhance the experience by providing a closer look at the moon as it crosses in front of the Pleiades. The soft glow of the crescent moon will be visible to the naked eye, but binoculars will help you catch finer details of the stars as they briefly disappear and then reappear. For optimal viewing, check your local sunrise and sunset times to ensure you’re outside at the right time. This event promises to be one of the best skywatching moments of 2025, and it’s one that should not be missed.