Something special is happening in the sky tonight: The planets Mercury, Jupiter, and Saturn will all appear near to each other in a rare triple conjunction.
This event occurs as all of the planets are orbiting around the sun at different distances, and occasionally those orbits line up so that multiple planets appear close to each other. This means you can look in one section of the sky and see all three planets close together tonight.
This follows the “Great Conjunction” which occurred at the end of December last year, when Jupiter and Saturn appeared closer together than they had in 800 years’ time. Now Mercury will be joining them, and the three will be visible at their closest just after sunset on Sunday, January 10. If you miss the event tonight, you’ll have another chance tomorrow night, as the planets will be close by on Monday, January 11 as well.
The event, called a planetary trio, will be visible just after sunset and will appear close to the horizon in the southwestern sky. As there will still be a glow from the sunset and it can be hard to see bodies near the horizon, it’s a good idea to use binoculars if you want to catch the planets slinking past each other.
If you’re outside tonight and hoping to catch the event, you can follow the instructions from the astronomy magazine Earth & Sky to find the trio. The planets will appear within a circle less than 5 degrees wide, which is the equivalent of three fingers together held at arm’s length. Jupiter will be the brightest of the three planets, and should be visible with the naked eye, so train your binoculars on Jupiter to spot Mercury and Saturn too.
Earth & Sky also advises finding an unobstructed horizon in the direction of the sunset and making sure you start looking no more than 45 minutes after the sun has gone down.
After Monday, Mercury will have passed by Saturn and Jupiter and will no longer appear near to the other planets. However, Mercury will continue to be visible in the evenings in the west-southwest direction just after sunset.
