You will probably hear phrases like "The Great Conjunction", "Christmas Star'' or "Double Planet" a lot this month. But what do they all mean?!

THE SHORT STORY:

Jupiter and Saturn are going to align so closely, that they will almost appear to collide or look as one radiant point of light from our vantage point on Earth later this month!

THE SCIENCE BEHIND IT:

The word conjunction is used in astronomy to describe a meetings of planets and other objects in our sky. The term "Great Conjunction" describes the meeting of two of the biggest objects in our solar system: Jupiter and Saturn.

Jupiter and Saturn have spent most of 2020 traveling across the sky together, but this month, they will really put on a spectacular show! Over the first three weeks of December, watch each evening as the two planets get closer in the sky than they've appeared in two decades!

HOW TO FIND IT:

All you have to do is look for them low in the southwest in the hour after sunset. "The Great Conjunction" will occur on December 21st and the two giant planets will appear just a tenth of a degree apart – that's about the thickness of a dime held at arm's length!

HOW RARE IS THIS?

NASA says this event occurs every 20 years, during this century, as the orbits of Earth, Jupiter, and Saturn periodically align making these two outer planets appear close together in our nighttime sky.

However, according to EarthSky, this will be the closest Jupiter-Saturn conjunction since 1623, but that conjunction was very close to the sun and it is believe it went unnoticed by many. That means the closest observable Jupiter-Saturn conjunction was back in 1226 during medieval times!

This will be the "greatest" great conjunction between Jupiter and Saturn for the next 60 years, with the two planets not appearing this close in the sky until 2080!!