The ability to see an entire planet in the night sky isn’t always a rare occurrence, but it’s something most people don’t want to miss when it does become prominent. Well, everyone can get their chance this week, as Mercury intends to pass quite close to Venus in a ‘quasi-junction’ at dusk tonight, January 5th.
This evening, Venus will sit comfortable at magnitude -3.3 around 18 degrees east of the Sun in the sky. Seemingly, there will be a narrow window to view the planet, as it will sit 10 degrees above the southwestern horizon seen from latitude 40 degrees north for an hour after sunset. A clear horizon will definitely be wanted for anyone hoping to experience the view, and binoculars will certainly make things a little easier.
If you’re viewing the spectacle tonight, then you may notice a small bit of light just a little lower to the right of Venus – that will be Mercury passing close by the planet. The second planet won’t quite be as bright as Venus, but it should be clearly visible for a limited amount of time during this junction.
Throughout the week, Mercury will appear to move across the sky as the nights pass, coming closer and closer to Venus as it does so. The planet will cross over the one-degree separation threshold sometime between January 8th and January 12th. Dusk hours will be the best time to see this alignment.
If you’re lucky enough to have a telescope lying around, both planets will be visible within the same lens space, offering a perfect view of the two planets. Both will appear about the same size.
Universe Today notes how interesting it is that the two planets will come so close together, yet neither will meet within the same space. Mercury will always be just a little ways off from Venus, offering everyone the chance to see both planets eerily close together.
This will be the only time since 2012 that the two planets have been this close together in our night sky, meaning you really won’t want to miss this, as it happens only ever few years or so. However, for one that was readily visible for everyone to see, you have to go way back to 2005, and October 2001 for a true quasi-junction.
If you miss this week’s event, then you will have to wait until May 13, 2016 for another chance to see Mercury this close.