A "Christmas star" will light up the sky on the December Solstice, a rare "double planet" event that hasn't been seen since the Middle Ages. These two planets have not appeared to be this close together from Earth’s vantage point since predawn March 4, 1226.
On the evening of Dec. 21, Jupiter and Saturn will seem to inch incredibly close to each other, looking like one single bright star. In reality, they will be hundreds of millions of miles apart. When two celestial objects closely approach each other in the sky, astronomers call it a conjunction, according to AccuWeather.
Jupiter and Saturn have formed a conjunction in the past, but they haven't gotten this close, or formed a "great conjunction," since 1623, Earth Sky reported. In that year, it was not visible because it happened during the day.
If you want to catch the rare event, you'll have to act quickly. The planets will dip below the horizon at around 7 p.m. that night. The two planets will be visible the entire last week of December.
This isn't the only astronomy event that will happen in December. One of the best meteor showers, the Geminid meteor shower, and a total solar eclipse will also happen. Here's a breakdown of the astronomy events happening this month.
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