Jason E. Andersen

Bonus Fun Fact: This December brings a rare astronomical sight — the two largest planets in the solar system, Jupiter and Saturn, will appear as a double planet. As the planets orbit the sun, they do so at different speeds and angles (and lots of other factors). Occasionally, the positions of the planets align with our perspective on Earth and they appear on top of one another. Astronomers call this a conjunction. Jupiter and Saturn will be in conjunction on Monday, December 21st. This is when the two planets will appear closest, although they will also appear pretty darn close the few days before and after. Jupiter and Saturn can be seen at dusk and early evening by looking just above the southwest horizon.

Bonus Bonus Fun Fact: Conjunctions between Jupiter and Saturn are fairly rare, happening only once about every 20 years. However, this conjunction is exceptionally rare. The two planets have not appeared this close since 1623, almost 400 years ago.

Bonus Bonus Bonus Fun Fact: While Jupiter and Saturn appear to be close by, they are not. Quite not, in fact. Jupiter is about 539 million miles from the Earth, on average. Saturn is about 403 million miles beyond Jupiter. Consider that the Earth is a little over 91 million miles from the Sun, and it gives you some sense of the scale of this conjunction photo-bomb.