Venus will pass between the Earth and sun on Saturday during what’s called an inferior conjunction.
The moment of conjunction will happen at around 9 p.m. EDT, but don’t plan on seeing the linkup. The sight is extremely difficult to spot without special equipment and a trained eye.
“The glare from the sun makes it really, really difficult to see,” said Michelle Nichols with Chicago’s Adler Planetarium.
A conjunction happens when two celestial bodies appear close together in the sky. It could be two planets, or a planet and the sun.
Since Venus and Mercury are “inferior” planets compared with the Earth — meaning their orbits are closer to the sun, according to NASA — they create inferior conjunctions when swinging between the sun and our planet. For Venus, these events happen relatively often, every 19 months or so, according to the science site EarthSky. The alignment during an inferior conjunction is approximate, as opposed to direct, which scientists would call a “transit.” Those rarely happen.
Geary Albright, an astronomer and professor at James Madison University, told The Associated Press some people colloquially refer to the type of conjunction happening this weekend as a “Venus kiss,” because of the planet’s relatively close proximity to the Earth.
NASA/JPL-Caltech via AP 
Venus has phases just like the moon. Before and after the conjunction, Venus looks like a thin crescent — though only telescopes can see it. Those looking for signs of the transition can watch Venus move from the evening to morning sky Sunday.
In the nights leading up to the conjunction, find a flat area and look near the horizon just after sunset to glimpse Venus before it sets. It appears as one of the brightest objects in the sky.
After the conjunction, Venus will be visible in the morning sky just before sunrise. EarthSky scientists advised that people hoping to catch a glimpse of it look eastward on the horizon Sunday morning, about half an hour before sunrise. Some may be able to spot Venus shining brightly near the point where the sun ultimately emerges. Take precaution to not stare directly at the sun.
While this weekend’s event isn’t much of a visual spectacle, scientists say it’s an opportunity to track how the planets shift in space.
“Get a chance to get to know Venus,” said Nichols.
Paul McCartney’s “The Kiss of Venus” was partly inspired by a book chapter describing the inferior conjunction. And two upcoming NASA missions will put a spotlight on Venus, investigating how it formed and why it turned out so different from Earth.