PORTLAND -- Tuesday's first of four lunar "blood moon" eclipses will mark a major earth-shattering event, depending on your viewpoint — either the possible start of the end of the world or Tax Day.
It could also be just a spectacularly beautiful astronomical event over the next two years.
The tetrad — or four consecutive and complete lunar eclipses occurring at approximately six-month intervals — will all be visible over the United States this year and next, according to NASA lunar eclipse expert Fred Espenak.
The viewing sky forecast for Portland is uncertain, according to KGW meteorologist Rod Hill.
"There is hope to at least see a partial view," Hill said. "Increasing cloudiness this evening may thicken and take away our view, but we may get lucky! It will be safe to view the eclipse with a naked eye.".
The eclipse will begin at 9:55 p.m. and reach totality at 12:08, lasting for 73 minutes.
OSMI planned an eclipse-watching party in Estacada.
While Espenak sees it as a frequent and naturally occurring event, best-selling author and Texas televangelist pastor John Hagee sees the four blood moons as evidence of a future "world-shaking event," possibly the beginning of the end of the world.
The controversial 73-year-old founder of Texas' Cornerstone Church says he has been preparing for the tetrad for years. The preparation includes a book — Blood Moons: Something is About to Change and an online TV special Tuesday.
"What is the prophetic significance (of the four blood moons)? Is this the end of the age?" Hagee asked his congregation during a sermon shortly after his book was released, Christianity Today reports.
He cites Acts 2:19-20 as a sign: "And I will show wonders in Heaven above and signs in the Earth beneath, the sun shall be turned into darkness and the moon into blood before the coming of the great and awesome day of the Lord."
Hagee, who sees the tetrad as particularly meaningful for Israel, says previous tetrads, in 1492, 1948 and 1967, coincided with such events as the expulsion of Jews from Spain at the end of the Inquisition, statehood for Israel, and the Six-Day War.
Pastor John Hagee Texas televangelist John Hagee speaks during a visit with Evangelical Christians to Ariel Israeli settlement in the occupied Palestinian territory on April 3, 2008.
NASA's Espenak does not consider tetrads as particularly rare, noting in a statement that there are nine sets of tetrads during the 21st century. He notes that there have been periods with no tetrads, notably from 1600 to 1900.
"The most unique thing about the 2014-2015 tetrad is that all of them are visible for all or parts of the USA," Espenak said in a prepared statement.
The full eclipse is known as a "blood moon" because, NASA explains, the sunset red glow that rings the Earth as it blocks the light from the sun is cast upon the moon.
The first one in this tetrad begins at 2 a.m. ET Tuesday. The other dates are Oct. 8, April 4, 2015, and Sept. 28, 2015.
In 2008, Hagee was criticized for suggesting that Hurricane Katrina was a result of God's wrath toward the city of New Orleans for planning a rally for gays and lesbians.