Perhaps you’ve heard of the astronomical event that scientists are calling the great conjunction and that some people are calling the Christmas Star. It should be very visible from all area in the Triangle, as long as skies are clear!
Skywatching is free and fun! Bundle up and head outside!
What is the Great Conjunction?
From the vantage point of Earth, Jupiter and Saturn are inching toward each other in the sky. In reality they are over 400 million miles from each other, but to our eyes, they are very close, and getting closer.
How close? At their closest they will be just 0.1 degrees apart. That’s about 1/5 of a full moon’s diameter.
When planets and other objects meet on our sky’s dome, astronomers call this a conjunction. Saturn and Jupiter are the largest planets in our solar system, so their meeting is the great conjunction.
The great conjunction will take place December 21st, 2020. Some people are calling it the “Christmas Star,” due to its proximity to Christmas. Of course it has nothing to do with Christmas and is not a star, but that won’t prevent the nickname from taking hold!
Keep reading to learn about the astronomical event, how to watch on your own, plus some virtual skywatching events. We’ve also included some tips on photographing the event.
Keep reading to learn about the astronomical event, how to watch on your own, plus two virtual skywatching sessions!
It’s not that rare for Saturn and Jupiter to experience a conjunction. It happens every twenty years, according to earthsky.org.
Saturn takes 30 earth years to go around the sun and Jupiter takes 12 earth years. So every 20 years, Jupiter catches up with Saturn, as viewed from Earth. If you’re good at math, you can figure out why they meet up every 20 years, but here at Triangle on the Cheap, we’re taking the word of the astronomers.
But although great conjunctions are not that rare, the one that’s about to happen is the closest the two planets will have been since 1623. So, this one will be an exceptionally great great conjunction.
During the great conjunction in 2000, Saturn and Jupiter were near the sun in our sky, which made it hard to observe, but this time they’ll be much lower in the horizon, and should be pretty easy to see, as long as the sky is clear.
Jupiter is brighter than any star, and Saturn isn’t quite as bright as Jupiter, but is still as bright as a star. How can you tell that you’re looking at a planet and not a star? Planets shine steadily. They don’t twinkle like stars.
You won’t need any highly specialized equipment, although binoculars or a small telescope will help. You won’t need to go to a super-remote location to see it, although the experience will definitely be enhanced if you’re in a location with less light pollution.
December 21st, 2020, is also winter solstice in the Northern Hemisphere, which means that the sun is in the southernmost position in the sky, and travels its lowest and shortest path across the sky. So, this is the shortest day of the year, in terms of hours of sunlight.
Sunset will be at 5:15 p.m. on December 21st.
Some tips from NASA:
- Jupiter and Saturn will appear brighter than nearly every star. They can be seen from large cities.
- You’ll need a clear view of the southwest.
- The planets will be visible in early evening.
- Start around sunset, and try to watch for an hour or two to see how they change
- The crescent moon will pass near the planets a few days before the conjunction, making for an interesting photo
If you miss the Great Conjunction on December 21, 2020, don’t despair. You’ll get another chance on March 15th, 2080.
Photographing the Great Conjunction
NASA has a comprehensive guide to photographing the great conjunction. Follow that link for the full guide.
Here are a few of the tips:
- Since Jupiter and Saturn will appear as points of lights, make your photo more memorable by framing the planets with something like an outdoor landscape or the silhouette of a tree.
- Use a tripod to hold your camera steady. If you don’t have one, brace your camera against something like a fence or a car.
- Try to capture the planets both during sunset and in complete darkness.
- If you’re using a DSLR camera, set your focus to Infinity (Manual Focus Mode) so that the planets will be sharp.
- Set your aperture wide open, to let in the maximum amount of light.
- To capture Jupiter and Saturn as sharp points while using a tripod, use a shutter speed of up to a few seconds. If you’re using a wide-angle lens you can use a longer exposure
- If you use a 200 mm telephoto lens you should be able to see Jupiter’s four bright moons in a short exposure. Saturn’s rings will usually need a longer lens or a telescope.
Virtual Skywatching Events
Morehead Planetarium
Morehead Planetarium and Science Center and Raleigh Astronomy Club are joining together to host a virtual skywatching session on Monday, December 21st, 2020, at 6 p.m., via Zoom.
Here is the Zoom link.
More info on the event, from Morehead Planetarium:
See the Jupiter/Saturn conjunction close-up!
Morehead Planetarium and Science Center is teaming up with the Raleigh Astronomy Club (RAC) to offer a free virtual skywatching event for the Dec. 21, 2020 conjunction of Jupiter and Saturn—the closest apparent pairing of these two planets since the year 1623, and the closest readily observable one since 1226.
RAC members and NASA/JPL Solar System Ambassadors Mike Keefe and Doug Lively will share live views from their telescopes of Jupiter and four of its moons, and Saturn and its spectacular rings—all in the same field of view of the telescope.
We’ll discover why the planetary pile-up (and apparent massive violation of social distancing) is happening, what makes this one so special, and how Jupiter and Saturn are in fact giving each other, and us, LOTS of space. We’ll also take a look at Mars and the Moon, and you’ll have a chance to ask questions. Join us in observing and learning about several of our solar system neighbors! Appropriate for all ages.
Kopernik Observatory & Science Center
The Kopernik Observatory & Science Center in Vestal, New York, is hosting a live stream of the Great Conjunction, starting on Monday, December 21st, 2020, at 5 p.m., on YouTube.
More info on the event, from Kopernik Observatory:
Join Jeremy Cartie, Kopernik Educator on Kopernik YouTube channel for this event.
In the early evening of December 21, Jupiter and Saturn will be as visually close to each other since 1623, being only 0.1 degree apart. They will both easily fit inside the view of a single telescope eyepiece. Kopernik’s resident Livestream Astronomer, Jeremy Cartie, will offer a livestream of this conjunction through Kopernik’s telescopes. The next time these two planets will be this close will be in March of 2080, so this is the year to catch the event. Let’s hope for clear skies that evening and tune in early as this conjunction will drop out of site for us at Kopernik by 6:15 pm.
More about the great conjunction
- EarthSky.org (where we learned almost everything we talked about in this post)
- Nasa.gov (statement on the astronomy events in December)
- Nasa.gov (tips for photographing the great conjunction)
More upcoming astronomical events
- Ursides Meteor Shower: Peak dates December 21st and 22nd, 2021. Could view as many as 10 meteors in an hour.
- Cold Moon: December 30th. The last full moon of the year is called the Cold Moon, or Long Nights Moon or the Moon Before Yule.
- Earth’s Perihelion: January 2nd. This is the time when the Earth is at the closest point on its orbit all year to the Sun.
- Quadrantids Meteors: Peaks on the night of January 3rd and the morning hours of January 4th.
