Dec. 21 (UPI) -- Google is celebrating a rare occurrence between Jupiter and Saturn known as the great conjunction, with a new Doodle.
Jupiter and Saturn, the two largest planets in the solar system, will nearly overlap as they cross within .1 degrees of each other an hour after sunset on Monday.
The event hasn't been seen since the Middle Ages. The two planets will actually remain 450 million miles apart but will appear closer.
Jupiter, an hour after sunset, will be easily visible in the southwestern sky. Saturn will be fainter and appear slightly above and to the left of Jupiter until Dec. 21 when Jupiter will overtake it and the planets reverse positions in the sky.
The planets can be seen without the use of binoculars. The great conjunction happens on the longest night of the year in the northern hemisphere and the longest day of the year in the southern hemisphere, as they experience the first days of winter and summer, respectively.
Google's homepage pays homage to the great conjunction and features an animated sequence of Saturn and Jupiter giving each other a high five.
The year's final meteor shower will also occur Monday.