What is a planetary conjunction? When, how to see moon, Saturn in January

• Saturn and the moon will appear close together in the night sky in an event known as a conjunction.
• The celestial event will be visible for one night on Friday, January 23, after sunset.
• To see the conjunction, observers in the Northern Hemisphere should look to the west to find Saturn below the moon.

Saturn and the moon are about to meet up for a short-lived cosmic hangout.

That's good news for avid skygazers, who will in one week have a chance to spot the celestial pair sharing a section of the night sky for one night in January. The rendezvous is what's known in astronomy as a conjunction, and it presents spectators with a rare opportunity to see a phenomenon in which at least two celestial bodies appear from our vantage on Earth to be near one another.

The impending conjunction is also the latest celestial display lighting up Earth's night skies in January after a group of stars known as the beehive cluster became visible earlier in the month.

Here's what to know about the Saturn and moon conjunction and how to see the celestial objects sharing a section of the night sky.

What is a planetary conjunction?

A conjunction is an astronomical event in which at least two planets – or, in this case, a planet and a moon – appear to our vantage from Earth to be close together in the sky.

Even though the planets are in reality still tens of millions of miles apart, the events present a special opportunity for astronomers and casual stargazers to see multiple worlds in our solar system at one time.

So, what causes conjunctions to take place?

As planets in our solar system orbit the sun at varying speeds, sometimes their orbital paths bring them close together on the same side of the sun. The same can be said of the moon, which instead orbits Earth.

When this event lines up with our view from Earth, we get a conjunction, according to the nonprofit Planetary Society.

When is the Saturn, moon conjunction?

Saturn and the moon are due to share the sky for one night on Friday, Jan. 23, after sunset and before sunrise, NASA said in a monthly skywatching guide.

Those who look up that night have not only a chance at seeing the moon – Earth's only natural satellites – but Saturn, the sixth planet from the sun and the second largest in the solar system after Jupiter.

How full will the moon be during the conjunction? What to know about lunar phase

The moon is due to be about 23% full and in a waxing crescent phase on Jan. 23, according to the Old Farmer's Almanac.

That means a silver sliver of the moon will be visible, with most of its illuminated half facing away from Earth, NASA explains.

Where, how can you see celestial conjunction in January? Tips

For those in the Northern Hemisphere, which includes the U.S., spotting the conjunction is as easy as locating the moon.

Look to the west and you'll see Saturn located just below the moon "sparkling in the night sky," Chelsea Gohd, a science communicator at NASA's Jet Propulsion Laboratory in Southern California, explained in a video.

Do you need a telescope to see Saturn next to the moon in the sky?

Telescopes certainly will enhance the view – and may even unveil Saturn's rings – but spectators don't need any equipment to spot Saturn and the moon in the pre-dawn sky.

Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at [email protected]