Stargazers are in for a celestial treat this month. Alongside the Perseid meteor shower, a rare lunar event called the “Seven Sisters Eclipse” will grace the skies on July 20, visible to many across the U.S. and Canada.
During this event, the crescent Moon will pass in front of the Pleiades star cluster—also known as the Seven Sisters—briefly obscuring it from view. The Pleiades, or M45, is an open star cluster located about 445 light-years away in the constellation Taurus. Though named for seven stars, only six are typically visible to the naked eye.
According to NASA, the Pleiades contains over a thousand stars, though only a few of the brightest dominate the view. This cluster has been observed since ancient times, and Galileo was the first to study it through a telescope.
The lunar occultation of the Pleiades isn’t a one-time occurrence. Since September 2023, it has been visible monthly and will continue until July 2029. However, whether the Moon passes above, below, or directly in front of the cluster varies each month.
On July 20, the Moon will cross directly in front of the Pleiades. As Royal Greenwich Observatory astronomer Anna Gammon-Ross explains, the Moon’s changing altitude in the sky affects how the event is seen.
To view the eclipse, look toward the horizon in the early hours of Sunday morning. With the naked eye, you’ll see the Moon slowly covering the star cluster—a beautiful moment for skywatchers everywhere.
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