Jupiter and Saturn will be within 0.1 degrees of each other, forming the first visible “double planet” in 800 years

Before the end of 2020, Jupiter and Saturn will be so close that they will appear to form a “double planet”. The great conjunction, as the planetary alignment is known, has not happened for almost 800 years.

When their orbits line up every 20 years, Jupiter and Saturn are extremely close to each other. This happens because Jupiter revolves around the sun every 12 years, while Saturn’s orbit takes 30 years – every two decades Saturn is stoned by Jupiter, according to NASA.

However, the conjunction of 2020 is particularly rare – the planets have not been observed so close to each other since medieval times, in 1226.

“Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is exceptionally rare due to the proximity of the planets,” Rice University astronomer Patrick Hartigan said in a report. communicated. “One would have to go back to the dawn of March 4, 1226 to see a closer alignment between these objects visible in the night sky.”

Aligning with the solstice on December 21, 2020, the two planets will be only 0.1 degrees apart – less than the diameter of a full moon, EarthSky says. The word “conjunction” is used by astronomers to describe the meeting of objects in our night sky, and the great conjunction occurs between the two largest planets in our solar system: Jupiter and Saturn.

The planets will be so close that they will appear to overlap completely, creating a rare “double planet” effect.

How to look at the great conjunction

During the last great conjunction in 2000, Jupiter and Saturn were so close to the sun that the event was difficult to observe. But sky watchers should have a clearer view of the celestial event this time around. The great conjunction will shine soon after sunset, low in the southwestern sky, as seen from the northern hemisphere, according to NASA.

Throughout the month of December, sky watchers will be able to easily spot both planets. For the next three weeks, you can look up each evening to watch them get closer and closer in the sky.

Jupiter currently appears brighter than any star in the sky. Saturn is slightly darker, but still as bright as the brightest stars, with a recognizable golden glow.

Saturn will appear just east of Jupiter, and will even look as close to the planet as some of its own moons. Unlike stars, which twinkle, both planets will have a constant brightness, easy to find on clear nights.

The event is observable from anywhere on Earth, provided the sky is clear. “The farther north a viewer is, the less time they will have to see the conjunction before the planets sink below the horizon,” Hartigan said.

The planets will appear extremely close for about a month, which will give sky-watchers enough time to witness the spectacular alignment throughout the holiday season. The event lines up with the December solstice, marking the shortest day of the year in the northern hemisphere.

It will be the “biggest” big conjunction for the next 60 years, until 2080. Hartigan said that following this conjunction, the duo will not make such a close approach until after 2400.