International Observe the Moon Night 2025 is almost here! This year, on October 4, gaze at the moon as it rises in the eastern sky. Each year, NASA collaborates with global partners to get people involved in moon observation and to share knowledge about our exploration of this fascinating natural satellite.
If you’re interested in joining the fun, check out the Observe the Moon Night website. There are over 950 virtual and in-person events planned worldwide.
To make the most of your viewing experience, we’ve highlighted some incredible lunar features to look out for, whether you’re using a telescope, binoculars, or just your eyes.
1. The Terminator
The terminator is the line that separates day from night on the moon. On October 4, you’ll notice it on the left side of the nearly full moon. Just two days later, the moon will reach its full phase on October 6, resulting in a beautiful Harvest Supermoon.
At the top of the terminator, you can spot the shadowed Pythagoras Crater, about 75 miles wide. And just south of it, you’ll see the outlines of the Schickard and Byrgius craters.
2. Mare Nubium
Look toward the southern part of the moon to find Mare Nubium, or “Sea of Clouds.” This dark area showcases impacts from the Lubiniezky, Bullialdus, and Wolf craters.
Fun fact: These lunar seas developed billions of years ago when lava flooded impact craters. As the lava cooled, it created a smooth surface that still tells a story of the moon’s violent past.
3. Montes Jura
The Montes Jura mountain range is located at the northern edge of the Sinus Iridum, or “Bay of Rainbows.” Around 11 days after a new moon, these peaks catch sunlight beautifully, creating what looks like a “Golden Handle” on the moon.
4. Ejecta Rays
During a full moon phase, it’s easier to see ejecta rays. These bright streaks burst from impact craters like Tycho and Copernicus. Ejecta rays are formed when asteroids hit the moon, scattering reflective debris over large distances. Though all craters once had these rays, they fade over time. For instance, Tycho is about 108 million years old and still shows off its striking patterns.
This year be sure to participate and see some amazing sights. Sharing your observations has never been easier. Experts from various fields, like astronomy and science education, emphasize the importance of events like this for sparking interest in space. Surveys show that over 70% of participants report a heightened appreciation for astronomy after attending these moon-watching events.
Join in and be part of the excitement surrounding International Observe the Moon Night!
