The Great Planetary Conjunction of 2020

The Great Planetary Conjunction of 2020

As you may have heard, on December 21, 2020, the planets Jupiter and Saturn will be very close together in the sky, an event called a conjunction. Because this coincidentally is happening on the same day as the winter solstice, and only a few days before Christmas, a lot of media have dubbed this the Christmas Star. There’s been some confusion about what exactly that means and how you can see this event, so here’s a handy reference guide to the whole thing.

A circled star in the evening sky. A large black circle shows the zoomed-in view of the area which includes several stars as well as Saturn and Jupiter. Text aong the bottom reads,

What is happening?

The planets Jupiter and Saturn will appear very close together in the sky, almost touching, on the early evening of December 21st, 2020. This kind of event happens about every 19 years, when Jupiter passes Saturn as seen from the Earth, while all three planets are in their orbits around the Sun. However, usually the passage isn’t this close – so, we haven’t had a Jupiter-Saturn conjunction this close since the middle ages.

When can I see it?

It’s actually in progress already – Jupiter and Saturn have been visible in the evening sky for months, slowly moving closer together as Jupiter catches up to slower-moving Saturn. Over the weekend of December 18-20 the two are already closer together than the apparent size of the Moon in the sky. Each night they will be closer together, leading up to closest approach on the evening of Dec. 21, 2020. After the 21st, Jupiter will move farther away from Saturn night after night. The Manitoba Museum will be doing a live-stream telescope event on the early evening of December 21 so you can see the planets up close and in detail.

What will it look like?

With the unaided eye, you can see Jupiter as a bright white “star” in the southwestern sky right after sunset. Saturn is quite a bit fainter, and has more of an off-white colour. In the days before closest approach you’ll easily distinguish them as separate objects. On the evening of closest approach, most people will still probably be able to see them as two separate objects (unless you have less than 20/20 vision).

In a small telescope, you’ll be able to see both planets at the same time in a low-power eyepiece. As the sky darkens, you’ll also see some of the moons of Jupiter and Saturn appear. The Manitoba Museum will be doing a live-stream telescope event on the early evening of December 21 so you can see the planets up close and in detail.

What’s all this about a Christmas Star, then?

That’s… complicated. The common image many people have of the Christmas Star comes from many different sources. The Christian Biblical story of the “Star of Bethlehem” actually doesn’t say much about what the “star” looked like, but centuries of art and Christmas card images have turned it into a huge blazing beacon in the heavens. This event will not look like that. (See “What will it look like?” above.) The Star of Bethlehem actually wasn’t something that everyone saw – it was only the Magi, the “wise men from the East” who saw it. That alone tells us it probably wasn’t as simple as a bright light in the sky.

There are some theories that suggest that the “wise men from the east” were astrologers, and so they would have been excited about things like planetary conjunctions, things that were seen as significant but not immediately noticeable to the casual viewer. Things like planetary conjunctions would have been highly significant to the Magi, especially if they were rare events or repeated events. If we run with this hypothesis, there was a conjunction of Jupiter and Saturn in 7 B.C. – actually, there were three of them, in an even-rarer triple conjunction. This actually times out fairly well to match the Biblical account, since we know that the 8th-century monk who did the math to calculate the year 1 A.D made some errors and was off by a few years – the Nativity story probably actually occurred a few years before 1 A.D. in our current calendar. For example, King Herod, who was alive during the Nativity story, actually died around 4 B.C., so we know the story had to take place before then.

If this idea is correct, the wise men saw the triple conjunction in 7 B.C., interpreted it to mean there would be a royal birth in Judea, and traveled to the land of King Herod. King Herod had no idea what they were talking about – his court astrologers had not seen a “star” that they thought was important. (Neither did Chinese astronomers of the day, who took meticulous observations of any new objects like comets, new stars, and the like.) The wise men leave Herod and travel to Bethlehem, arriving sometime in 6 B.C. or perhaps a bit later.

None of this is certain, of course – there are other possible explanations for the Star of Bethlehem, like a conjunction of Venus and Jupiter in 2 B.C. that would have been the brightest star in the sky. And given the nature of the Nativity story, there isn’t enough evidence to even say whether the Star was an astronomical object, a divine inspiration, an interpretation by the wise men, or an idea added in later revisions of the Bible throughout the ages. And really, not everyone feels the Star of Bethlehem needs an explanation in the first place. As I said, it’s complicated.

So, because it’s possible that the Star of Bethlehem was inspired by a rare triple conjunction of planets in 7 B.C., and because this year we are seeing a single conjunction of the same planets Jupiter and Saturn, which happens to occur in December, the Great Planetary Conjunction of 2020 has been dubbed the Christmas Star. And so many people are expecting the Christmas Card version of the event: a huge light in the sky.

Conclusion

To some, the actual Planetary Conjunction of 2020 will fall short of their expectations. To others who attach religious significance to the idea of a Christmas Star, it might disappoint as well. But consider what is happening: humans, a part of the universe that has become alive and aware, are standing on a ball of rock hurtling through space, looking out at the two largest planets in our solar system. On December 21, 2020, those two planets will be lined up from our viewpoint, so that they will both be visible in a telescope at the same time – a very rare and pretty cool event to watch. In the days before and after, we can watch the clockwork of the heavens tick forward night after night, as the relative position of the Jupiter, Saturn, and Earth change as they orbit the Sun. Right now, a human-made robotic spacecraft is in orbit around Jupiter, beaming back close-up pictures of a gas giant planet covered with storms larger than the Earth. On some of the moons of the two planets, there may in fact be some form of primitive life, living there now: in the underground oceans of Europa, for example, or the thick atmosphere and methane seas of Titan. And we can participate in these grand cosmic events just by going outside and casting our eyes upwards on a clear winter’s night. I think that qualifies as a miracle of sorts, no matter what your beliefs are.

Scott Young

Scott Young

Planetarium Astronomer

Scott is the Planetarium Astronomer at the Manitoba Museum, developing astronomy and science programs. He has been an informal science educator for thirty years, working in the planetarium and science centre field both at The Manitoba Museum and also at the Alice G. Wallace Planetarium in Fitchburg, Massachusetts. Scott is an active amateur astronomer and a past-President of the Royal Astronomical Society of Canada.

Popping Pine Cones and Other Fun Facts About Conifers

I recently read that, thanks to Covid-19, there’s been a run on Christmas trees because so many people are staying home for the holidays this year. In a world that suffers from plant blindness (i.e. an inability to see the trees for the forest), “Christmas trees”, are among the most well-known “species” of plant. Except that “Christmas tree” is not actually A species; it is ANY kind of coniferous (i.e. cone-bearing), evergreen tree that we decorate. So, if you don’t know much about conifers, here are 10 fun facts about these common trees many of us share our homes with once a year.

Close-up on a low-to-the-ground Balsam Fir tree branch

1. Many different species are used as Christmas trees

Some of the most popular Christmas tree species in Manitoba are native ones: Eastern White Pine (Pinus strobus), White Spruce (Picea glauca) and Balsam Fir (Abies balsamea). Other species are non-native, most commonly Fraser Fir (Abies fraseri) and Scots Pine (Pinus sylvestris). How to tell them apart? Just remember this little rhyme about the needles of these trees: firs are flat, spruces are stiff, and pines are in pairs.

 

Balsam Fir is a popular Christmas tree because the needles are not shed as quickly as in spruce trees.

A stone partially embedded in grassy ground with a creeping vine-like plant with small green leaves and red berries growing across it.

2. Not all conifers are evergreens and not all evergreens are conifers

The term evergreen just means that the plants’ do not shed all of their leaves in autumn the way deciduous plants do. Being evergreen is advantageous for plants that grow in cold, nutrient-poor soils where organic matter decomposes slowly (i.e. pretty much all of Canada!). Most conifers are evergreens, but Tamarack (Larix laricina) trees are deciduous. Tamaracks can afford to regrow new needles each year because they can reabsorb many of the minerals in them before they turn yellow and fall off. Some flowering plants in nutrient-poor habitats, like Bearberry (Arctostaphylos uva-ursi), are evergreen, with thick, but broad (not needle-like) leaves that stay on all winter.

 

Bearberry, shown here growing over a rock, is an evergreen shrub that produces white, bell-shaped flowers and red fruits, not cones.

3. In conifers, the females are on top

Manitoba’s conifers are not like people: they don’t have different genders. Conifers produce both male cones, which produce sperm, and female cones, which produce eggs. The male cones are typically produced on the lower branches and the female cones on the top ones. This positioning helps to prevent self-fertilization because the sperm-containing pollen won’t fall on the trees’ own female cones.

Close-up of a green-brown Jack Pine cone on a tree branch.

4. Manitoba has popping pines

To protect Jack Pine (Pinus banksiana) seeds from predators like squirrels and birds, their cones are tough and tightly closed (i.e. serotinous). The cones will not open, sometimes for decades, until they are exposed to intense heat, such as that from a forest fire. In fact, shortly after a forest fire, you can hear the sound of Jack Pine cones popping open and releasing their seeds. You can hear this sound too, if you collect closed cones and put them near a bonfire or on top of a radiator.

 

Jack Pine is a conifer that has adapted to the natural forest fires that periodically occur due to lightning strikes.

5. Conifers can fly

The seeds of most conifers have a thin “wing” attached to them. These wings help the seeds, which are near the top of the tree, glide some distance away, so that the baby trees do not have to grow in the shade of their parent. Juniper (Juniperus spp.) and yew (Taxus spp.) seeds are contained in fleshy cones (incorrectly called “berries”), which are eaten by birds. Thus, they can also fly, although they will be in the stomach of a bird when they do. Fortunately, the seeds are usually not digested, just the fleshy part. They are usually excreted intact in the birds’ dung.

6. Conifers are always in your house (or ARE your house)

Unless you have a bidet, don’t use any paper products at all, and live in a house made entirely of straw, you have conifers in your house all the time. Paper products like toilet and wall paper, paper towel, newsprint, cardboard and printing paper are all made, at least in part, with “softwood” trees, which are conifers. As well, much of the timber we use to build our houses and furniture comes from conifer trees like pine and spruce. If you eat pesto sauce or drink gin, you are also consuming conifers. Pesto sauce is typically made with pine nuts, and gin is usually flavoured with juniper cones.

White Spruce tree growing around other kinds of trees in a wooded area.

7. A conifer is Manitoba’s provincial tree

Manitoba’s provincial tree is White Spruce (Picea glauca). This is the dominant conifer in North America, growing in every Canadian Province. Their life span is relatively short, about 250-300 years old, in part because spruce forests become more susceptible to wildfires as they age. White Spruce provides much of the habitat for migratory songbirds and small boreal mammals, which eat the insects that live on them, or the seeds of their cones. Crossbills (Loxia spp.) and squirrels are busy eating White Spruce seeds right now, even here in the city.

 

White Spruce trees grow in upland areas all over Canada’s boreal forests.

A leafless gnarled, twisted tree with a thick trunk growing in a lightly snowy landscape.

8. Conifers are the oldest trees

The Great Basin Bristlecone Pine (Pinus longaeva) is the worlds’ longest-lived, non-clonal tree species, typically surviving for thousands of years. The oldest individual of this species, found in California, was estimated to be just over 5,000 years old, so it germinated several hundred years before the Egyptians built the first pyramid.

 

The oldest trees in the world, Great Basin Bristlecone Pines, look just as you would expect an ancient tree to look: gnarled and knotty. From Wikimedia Commons.

At least nine people hold hands in a line, reaching around the visible half of a Giant Sequoia trunk in a wooden area.

9. Conifers are the biggest trees

A tree named “General Sherman” is the largest tree in the world at 1,487 cubic metres. It is almost 84 metres tall, about the height of a 26-story building, and has a 31-metre circumference at ground level. It is a species of Giant Sequoia (Sequiadendron giganteum), and can be found in Sequoia National Park in California. They make bad Christmas trees, cause who could ever get the star on top?

 

A Giant Sequoia with people at the base for scale. From Wikimedia Commons.

10. Dinosaurs ate conifers

Conifers are the oldest seed plants; they evolved about 300 million years ago in the Carboniferous Period. Unlike the earliest land plants, which still needed water to reproduce, conifers did not: their sperm became contained in pollen grains, which could be transported to other plants by the wind instead of water. This enabled conifers to live in relatively dry areas. They became the dominant plants during the “Age of Dinosaurs”: the Triassic, Jurassic and Cretaceous Periods. So, any plant-eating dinosaurs would probably have eaten conifers. Fortunately, dinosaurs are extinct so they will not eat your Christmas tree.

Wanting more conifer trivia? Check out this post from the past to learn why people drank conifer “beer”: click here to read.

 

Enjoy a tree-filled holiday!

Dr. Diana Bizecki Robson

Dr. Diana Bizecki Robson

Curator of Botany

Dr. Bizecki Robson obtained a Master’s Degree in Plant Ecology at the University of Saskatchewan studying rare plants of the mixed grass prairies. After working as an environmental consultant and sessional lecturer…
Meet Dr. Bizecki Robson

Astronomy Resources

Explore the stars from your own backyard! This page has resources for budding astronomers and scientists of all ages. Build your own star clock, track the International Space Station, connect with local Manitoba astronomy groups, and more.

The Northern Lights

  • SpaceWeatherLive.com offers forecasts for northern lights visibility on their website or via an app for IOS and Android.
  • On Facebook, the Manitoba Aurora and Astronomy group tracks local sightings and shares information on how to observe and image the northern lights in Manitoba.

Safe Sun Viewer

Use a cardboard box to safely view the sun during a solar eclipse! Follow the bilingual instructions at the Canadian Space Agency!

Build a Star Clock

Exploring the Sky

General Astronomy Information

Astronomy Groups in Manitoba

Astronomy Publications

  • SkyNews Magazine – the Canadian magazine of amateur astronomy. Lots of current information and useful links for amateur astronomers of any level.
  • The Royal Astronomical Society of Canada publishes several books useful to amateur astronomers in Canada.
  • Sky & Telescope Magazine – daily information updates, star maps, and a wealth of information for the amateur astronomer.

Astronomy Education Resources

  • The Astronomical Society of the Pacific – excellent site for teachers with lots of resources, lesson plans, and products for astronomy education. The site is based on the American curriculum but is still useful for Canadian teachers.

Space Exploration

Scott Young

Scott Young

Planetarium Astronomer

Scott is the Planetarium Astronomer at the Manitoba Museum, developing astronomy and science programs. He has been an informal science educator for thirty years, working in the planetarium and science centre field both at The Manitoba Museum and also at the Alice G. Wallace Planetarium in Fitchburg, Massachusetts. Scott is an active amateur astronomer and a past-President of the Royal Astronomical Society of Canada.

Choosing a First Telescope

By Planetarium Astronomer Scott Young

Choosing a first telescope is bit like buying a car – there’s no “best” car, but there is the one that will work best for you. It depends a bit on what you want to do with it, where you will observe from, and of course your budget.

Nightwatch book cover featuring the silhouette of a person looking into a telescope. The background shows a starry night sky lit in pinks and purples.First step: educate yourself. Pick up Nightwatch by Terence Dickinson. It will provide you with information on a first telescope, and help you use whatever telescope you buy. This is THE best book for first-time astronomers, and will help you not only choose a telescope, but learn to use it as well.

Second step: learn the sky. If you can’t point your finger at a galaxy, a star cluster, or a planet, you won’t be able to point your telescope at it either. Unless you spend big money, you’re not going to get a computerized telescope that will do everything for you – you still need to know where to look. Space is mostly empty space (hence the name), and so finding the interesting objects takes some work. Learn the constellations (again, Nightwatch is a great reference), use binoculars if you have them, get to know the sky, take an astronomy course (click here to learn about the current Dome@Home offerings), join an astronomy club (the local group is called the Royal Astronomical Society of Canada – Winnipeg Centre). All of these steps will help you get the most out of your telescope when you do get one, and will also help you know more about them before you buy one.

Now you’re ready for your first telescope. Here are some basic facts to help guide your choice.

The main thing about a telescope is its aperture – the diameter of the main lens or mirror. The bigger the aperture, the more “power” a telescope has – it gathers more light, it resolves finer detail, it makes objects look better. Of course, as the aperture increases the telescope also gets physically larger and more expensive.

Contrary to popular belief, magnification is not an important function of a telescope – any telescope can theoretically magnify any amount! What matters is, how much can a telescope magnify and still provide a clear image? Small department-store telescopes often claim “600x” or “1000x”, but that’s baloney. You can almost never use more than 200-300x on any telescope, because the atmosphere of the Earth is not steady enough – the image gets bigger but fuzzier, and you lose detail. Most observing is done in the 50x to 200x range of magnification. So, avoid any telescope advertised based on magnification – they’re trying to fool you into buying a junky telescope.

We also recommend you avoid a telescope with a computer or motors built in, unless you’re spending $800 or more – every dollar that goes into the computer is taken away from your optics, and you usually wind up with a telescope that isn’t very good optically or electronically. If you want this option, it will cost a significant amount of money if you want it to actually work. As an example, Orion’s computer-aided telescope line costs about $400 more than the equivalent manual scope.

One big question to consider: where are you using the telescope? If you have to carry it down stairs or load it in a car with a family every time you’re going to use it, I would recommend a different scope than if you’re going to use it mostly in your own backyard. Most “real” telescopes are bigger than the ones you see in camera stores, and are bigger than people expect. They’re not unreasonable, but they won’t fit in the back seat with two kids. The old-style “spyglass” on a spindly fold-up tripod that most people think of has been replaced by a sturdy large-diameter tube on a wooden box – they look more like a cannon.

Recommended Starter Telescopes

I have personally used both of these scopes, and can recommend them from experience as great instruments for exploring the Universe. Even though I have access to larger telescopes, I still use my personal GoScope 80 and StarBlast 6 for stargazing.

We invite you to order through our trusted online distributor, Orion Telescopes. Alternatively, we also recommend a local company that sells and repairs telescopes, Side Lines Distribution.

The universe awaits!

Scott Young

Scott Young

Planetarium Astronomer

Scott is the Planetarium Astronomer at the Manitoba Museum, developing astronomy and science programs. He has been an informal science educator for thirty years, working in the planetarium and science centre field both at The Manitoba Museum and also at the Alice G. Wallace Planetarium in Fitchburg, Massachusetts. Scott is an active amateur astronomer and a past-President of the Royal Astronomical Society of Canada.