What Is Occultation? Don't Worry, It's Not Quite As Witchy As It Sounds


On the evening of Sept. 18, as the cooler weather of fall creeps in and Halloween grows ever closer, those of us in the earthly realm will bear witness to a rare celestial occurrence: the occultation of three planets and a star. But, what exactly is occultation? Don't worry: despite its name, it's actually not that witchy.

Though the term may conjure up images of cauldrons, black cats, and magic potions, within the world of astronomy the word "occultation" simply means the passage of one celestial body in front of the other, a phenomenon that results in one planet hiding the other from view, according to Dictionary.com. It's a catchall term, one that applies to everything from solar eclipses (when the moon passes between the earth and the sun) to lunar "grazing" (which looks, from the earth's surface, like a star is winking in and out of sight — it's not, it's just the moon's visible edge passing by).

And while occultation is a fairly regular celestial event since the moon is continually in orbit, it rarely occurs on a such a large scale, as will be happening Sept. 18. The last time the moon occulted, or passed over three planets — Venus, then Mars and finally Mercury — in a 24-hour span was in May 2008. The next time a three-planet occultation will grace the sky? July 24, 2036.

The moon will also be occulting Remulus, a first-magnitude (meaning: brightest to the naked eye) star and the brightest within the Leo constellation. Moon! We get it! The nighttime sky is yours! You don't need to be stealing the spotlight! You own it!

Though this wild night of occulting may leave the moon a bit tired, those of us on the ground won't be quite as spent. Most of the action won't even be visible from the earth's surface without a serious set of stargazing tools, and for much of the world, the occultations will actually be occurring during the daytime hours of Monday. This round of occultation, it seems, is more academic than it is for show.

Both the celestial "occult" and the supernatural "occult" stem from the same latin root — "occultus," meaning "clandestine, hidden, secret." And although astronomy likes to make it clear that it's strictly science-based, there's still a connection between the literal and the spiritual blocking of planets.

Within the astrology world, occultation often serves to put our lives into perspective, forcing us to step outside our individual experiences and realize just how big and interconnected the universe is. It can be easy to forget that we are far from alone — seeing, or even feeling the effects of the moon directly blocking another celestial body can jolt us into realization.

Astrologers also see an occultation as a blocking of energy (ugh, thanks a lot, Moon), so think of it as a reset button — much like an eclipse, or similar astronomical event. The concerns of the occulted body are first muted, and then emphasized. In the case of Sept. 18, considering the planets being occulted are Venus, Mars and Mercury — which represent love, war, and communication respectively — there might be one hell of an emotional rollercoaster waiting for us when the lunar event occurs.

Need some survival tips? The same ones used during eclipses can apply during any sort of occultation. You might feel more emotional — so, breathe through it, take your time, keep your schedule open (occultations are known as "wild cards," according to Astrology Zone) and don't be too quick to judge the effects. With occultations, something ends and another begins. Embrace the shake-up.