Jupiter and Saturn to align in a very rare 'Double Planet' conjunction on December 21.

Artist’s concept of Jupiter and Saturn in December of 2020, as viewed from a space-based perspective.  Chart via Jay Ryan at ClassicalAstronomy.com.

Jupiter and Saturn to align in a very rare Double Planet conjunction last happened in the year 1226. This even is significant due to its happening after 800 years.

Planet Jupiter and Saturn will be aligned in conjunction on 21 December. According to reports in Chron, the spectacular even will appear in the night sky.

The conjunction that will happen in December will see Jupiter and Saturn be only 0.1 degrees apart. EarthSky adds that the conjunction in 2020 won’t be matched again until the Jupiter-Saturn conjunction of 15 March 2080.

Although the conjunction happens every 20 years, the one happening on 21 of December is rare has the degree of conjunction is about 0.1 degrees. Closed conjunction had happened in the year 1623, fourteen years after Galileo made his telescope.