Before 2020 will finish, Jupiter and Saturn will be so close that they seem to form a “double planet.” The great conjunction, because the planetary alignment was known, has not occurred in nearly 800 years.
When their orbits match every 20 years, Jupiter and Saturn get extremely close to each other. This occurs because Jupiter orbits the sun every 12 years, while Saturn’s orbit takes 30 years – every couple of decades, Jupiter laps Saturn, according to NASA.
However, the conjunction of 2020 is especially rare – the planets have not been observed close together since the medieval time, in 1226.
Rice University astronomer Patrick Hartigan said in a statement. “You’d have to go all the way back to just before dawn on March 4, 1226, to see a closer alignment between the objects visible in the night sky.”
According to the winter solstice on December 21, 2020, the two planets will be exactly 0.1 degrees apart – less than the diameter of a full moon, EarthSky says. The word “connection” is used by astronomers to describe the encounter of objects in our night sky, and the great connection occurs between the two largest planets in our solar system: Jupiter and Saturn.
The planets will be so close, from some perspectives they will overlap completely, creating a rare “double planet” effect.
However, although they may appear to the naked eye very, very close, in fact, they are still hundreds of millions of miles apart, NASA said.
How to watch the big 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 skiwaters should have a clearer view of the heavenly event. The great conjunction will shine bright shortly after sunset, low in the southwestern sky, as it is shown from the Northern Hemisphere, NASA says.
Throughout the entire December, squatters can easily recognize the two planets. In the next three weeks, you can look up every evening to see how they get closer and closer in the sky.
Jupiter is currently brighter than any star in the sky. Saturn is slightly dimmer, but still just as bright as the brightest stars, with a recognizable golden glow.
Saturn will appear just to the east of Jupiter, and will even look as close to the planet as some of its own moons. Unlike stars, which sparkle, both planets will maintain consistent brightness, easy to find on clear nights.
The event is observed from anywhere on earth, if the sky is clear. “The farther north there is a spectator, the less time they will have to catch a glimpse of the connection before the planets sink below the horizon,” Hartigan said.
The planets will appear extremely close for about a month, giving skiers a lot of time to see the spectacular alignment over the holiday season. The event aligns with the December solstice, marking the shortest day of the year in the Northern Hemisphere.
This will be the “biggest” big conjunction in the next 60 years, until 2080. Hartigan said that after this combination, the duo will not make such a close approach until sometime after the year 2400.