The year 2023 is only three weeks old, but we’re already on the brink of witnessing the closest planetary conjunction observable to the naked eye this year.
Venus will coincide with Saturn on Sunday (January 22), and they appear close enough in the sky that they can be seen through a telescope. Close coupling will also be visible to the naked eye.
These two planets, as well as the crescent moon, will appear in an ever-changing display at dusk this weekend into the beginning of next week. Planets will sink lower as twilight deepens, so make sure you have a clear, unobstructed west-southwest horizon for the best view.
Related: The night sky, January 2023: What you can see tonight [maps]
Planetary Principles
Anyone looking close to an hour after sunset will immediately see the planet Venus, which has been stationary in the evening sky since the end of November. As is usually the case, Venus shines brilliantly (currently it has a magnitude of -3.9).
This is the beginning of the spectacular evening apparition of Venus, which will see it literally soar high into the sky by late spring as it doubles in brightness.
The other planet is Saturn, which classifies the brightness of a star of the first magnitude. At magnitude +0.8, it will rank 12th among the list of 21 brightest stars (between Altair and Aldebaran). Yet, despite this respectable level of brightness, it appears dim next to dazzling Venus; Huge difference in brightness as Saturn will only appear 1/76 as bright. And it can be somewhat difficult to capture Saturn during the evening twilight without optical aid. Binoculars will be more helpful.
But unlike the ascending Venus, Saturn is decreasing with each passing night and becoming increasingly immersed in the bright evening twilight, as it approaches solar conjunction on February 16th.
Read more: Saturn: everything you need to know about the ringed marvel
weekend pass
So, this weekend, watch bright Venus transit Saturn. On Saturday (January 21), Saturn will stand just 1 degree above Venus and slightly to the left. This measures nearly twice the apparent width of the Moon.
By the following evening (Sunday, January 22nd) Venus will sit just 0.35 degrees to the left and just below Saturn. This equates to just under three-quarters of the Moon’s width; You can place both planets in the same field of view of a low-powered telescope. Venus appears as a relatively small, featureless disc. For Saturn, Murray Paulson notes in a guide to the Royal Astronomical Society of Canada:
“With its amazing ring system, Saturn is probably the most amazing planet in the solar system. The rings can be seen even in high-powered still (or still image) telescopes and small observing telescopes.”
From personal experience, a telescope with a magnifying lens of at least 30 power will make the rings easily visible. They are currently inclined by more than a dozen degrees to our line of sight.
Read more: Venus: The second hottest planet from the Sun
Then there is the moon
Adding to this evening show is our closest neighbor in space; A very narrow (2% lit) crescent moon will slide in front of the binary planet during the evenings of Sunday (January 22) and Monday (January 23). You’ll definitely need binoculars on Sunday to scan the bright twilight sky just half an hour after sunset to catch a glimpse of the moon for the first time.
Venus should be easy enough to see, but there is the matter of capturing Saturn as well as a sliver of the Moon — just one day after the new phase — which will be placed at the end of a vertical line that extends eight degrees below the two. planets. (For comparison, your clenched fist at arm’s length is about ten degrees wide.)
The next evening – Monday, January 23 – the entire composition will change radically.
Check it against a dark west-southwest sky about an hour after sunset. You’ll immediately notice that Venus has moved to a position about one degree higher and left of Saturn. A slightly wider crescent moon (6% lit, much easier to see) will overtake the planets and will now appear about eight degrees higher and left of them.
Read more: What is the moon phase today? Phases of the moon 2023
In fact, they are all widely separated
Finally, keep in mind that when you look at this clustering of the slender moon and two planets in the evening sky this weekend, they are all at varying distances from our Earthly perspective. The moon is actually now as close to Earth as it will get all this year, reaching a maximum perigee distance on Saturday (January 21) of 221,700 miles (356,600 km), followed by Venus at about 143 million miles (230 million). How many). Finally, the most distant is Saturn, at 998 million miles (1.61 billion km).
If you don’t have all the optics you need to get a good look at Venus, Saturn, or anything else in the night sky, our guides to the best telescopes and best binoculars are a great place to start. If you’re looking to take pictures of the night sky, check out our guides on the best cameras for astrophotography and the best lenses for astrophotography.
Joe Rao is a teacher and guest lecturer in New York Hayden Planetarium (Opens in a new tab). He writes about astronomy for Natural History Journal (Opens in a new tab)the Farmers’ almanac (Opens in a new tab) and other publications. Follow us on Twitter @employee (Opens in a new tab) and on Facebook (Opens in a new tab).