Scheduled for this weekend and again in mid-February
The Christmas star, an occasional astronomical event that happens when Jupiter and Saturn, the two largest planets in the Solar System, form what resembles a double planet. It was one of the highlights of 2020.
2021 seems to top that. This weekend, Mercury will collaborate with the two gas giants in a “triple conjunction,” as the three planets will be within a couple of degrees from each other during the night sky.
NASA wrote the following on its website-
“From Friday evening to Monday evening, the planet Mercury will appear to pass first by Saturn and then by Jupiter as it shifts away from the horizon, visible each evening low in the west-southwest and setting before evening twilight ends,”.
According to Forbes, the three planets will be in the same two degrees of the sky in the Capricorn constellation.
As per EarthSky.org, skywatchers may require binoculars to catch some of the planets. However, the event can be witnessed by searching for Jupiter first, then locating Saturn and Mercury. Jupiter will be the brightest among the trio.
The science website opines that it is ideal to locate an unobstructed horizon in the direction of sunset to view these planets, starting stargazing no less than 45 minutes after sundown.
Dissimilar to the “Christmas star,” this triple conjunction of planets occurred recently, last in October 2015. Jupiter and Saturn form double conjunction once in approximately 20 years, though the latest event was the closest the two had been to each other after 1226 A.D.
Post this weekend, the next time the trio will form triple conjunction is on Feb. 13, 2021, i.e Valentine’s eve.
The next two triple conjunctions are set for April 20, 2026 (Mercury, Mars, Saturn) and June 16, 2028, when Mercury, Venus and Mars create the magic.