Could Tuesday’s “blood moon” event be connected to Jesus’ return? Some Christians think so.

Around 2 a.m. EST on Tuesday, the moon will slide into Earth’s shadow, casting a reddish hue on the moon. There are about two lunar eclipses per year, according to NASA, but what’s unusual this time around is that there will be four blood moons within 18 months—astronomers call that a tetrad—and all of them occur during Jewish holidays.

A string of books have been published surrounding the event, with authors referring to a Bible passage that refers to the moon turning into blood. “The sun shall be turned into darkness, and the moon into blood, before the great and terrible day of the Lord,” Joel 2:31 says.

In the New Testament, Acts 2:20 echoes the same doom: “The sun shall be turned into darkness, and the moon into blood, before the great and notable day of the Lord.”

Recent books capitalizing on the event include Blood Moons: Decoding the Imminent Heavenly Signs by Washington state author Mark Biltz; Blood Moons Rising: Bible Prophecy, Israel, and the Four Blood Moons by Oklahoma pastor Mark Hitchcock; and Four Blood Moons: Something Is About to Change by Texas megachurch pastor John Hagee.

Hagee’s book is drawing the most attention, with his book now No. 4 on The New York Times best-seller list in the advice/how to section, and No. 80 on USA Today’s best-seller list. The book by the controversial 74-year-old founder of San Antonio’s Cornerstone Church has also spent 152 days in Amazon’s top 100 books.

In his book, Hagee says something will happen to the nation of Israel due to the tetrad. The four eclipses occur on April 15 and Oct. 8, 2014, and April 4 and Sept. 28 next year. The ones in April occur during Passover, and the ones in October occur during the Jewish Feast of Tabernacles.

Jewish holy days revolve around a lunar calendar with Passover beginning on the first full moon after the beginning of spring, and the Feast of Tabernacles occurring on the first full moon after the beginning of fall. Hagee writes that every time a tetrad occurs on Jewish feast days, something traumatic and “world-changing” happens to Israel.

In 1492, the Jews were expelled from Spain and Christopher Columbus discovered America, giving the Jews a place to go. In 1948, the modern state of Israel was born, and in 1967, Israel won the Six-Day War and recaptured Jerusalem.

This time, Hagee suggests that a rapture will occur where Christians will be taken to heaven, Israel will go to war in a great battle called Armageddon, and Jesus will return to earth. Hagee has planned a special televised event on Tuesday on the Global Evangelism Television channel.

But NASA does not consider tetrads as especially rare, saying in a statement that there are eight sets of tetrads before the year 2100. The most unique thing about the upcoming tetrad is that they are visible from all or parts of the United States, NASA stated.