On June 17, skywatchers across parts of North America were treated to a beautiful celestial event: a lunar occultation of Venus. For a brief time, the Moon passed directly in front of Venus, temporarily hiding the bright planet from view.
While lunar occultations of Venus happen on average every few years, they are still considered somewhat rare. These events usually last only a few minutes to a little over an hour, and you must be in the right location on Earth to see them. Even then, clear skies are essential.
What is a Lunar Occultation?
The Moon occasionally passes in front of planets because they all travel along similar paths across our sky. These paths lie close to an imaginary line called the ecliptic, which is the path the Sun follows across the sky throughout the year.
The ecliptic marks the plane of Earth’s orbit around the Sun. Since most planets orbit within nearly the same plane, they also appear near the ecliptic when viewed from Earth. The Moon’s orbit is slightly tilted to the ecliptic, but it remains close enough to it that it sometimes passes in front of a planet.
When the Moon moves directly between Earth and another object in the sky, it blocks that object from view. Astronomers call this an occultation, a word that simply means “to hide.” Because the Moon and planets travel along similar paths, these events occur from time to time, though they are not visible from every location on Earth.
Why Some People Saw It and Others Didn’t
Interestingly, where you are located on Earth affects what you see. Because the Moon is relatively close to Earth, its position against the background sky appears slightly different depending on your location.
For some observers, the Moon passed directly in front of Venus. For others farther north or south, the Moon passed above or below the planet, and no occultation occurred at all. This means that even when an occultation is happening, only certain regions of Earth can witness it.
Venus Has Phases Too
The June 17 event also offered a chance to observe something many people do not realize: Venus goes through phases just like the Moon.
At the time of the occultation, Venus appeared in a waning gibbous phase, meaning more than half of its sunlit side was visible. Over the coming weeks, its appearance will continue to change as it moves around the Sun. By mid-August, Venus will reach a quarter phase, appearing half illuminated through a telescope. By late September, it will become a thin waning crescent.
As Venus swings closer to Earth in its orbit, it will also appear larger through a telescope. By September, its crescent shape will be so pronounced that observers may be able to detect it even through binoculars. Watching Venus go through all its phases provides clear evidence that the planet orbits the Sun, just as Galileo observed more than 400 years ago.
Looking Ahead
If you missed this month’s event, don’t worry—another lunar occultation of Venus will be visible from parts of the United States on October 10, 2029. Unfortunately, observers in Nashville will miss the actual occultation because the Moon will set before the event begins.
Even so, the close pairing of Venus and the Moon before the moonset should create a beautiful sight in the western sky.
Events like these remind us that the Solar System is constantly in motion. The planets and the Moon follow predictable paths, yet their changing positions can produce striking celestial displays. Occasionally, those motions align to create brief and memorable moments that offer a glimpse of the dynamic universe above us and our place within it.