I have been looking forward to this Conjunction on December 20-21, 2020 for quite some time, and I am happy that the word is getting out…
However, once again, I am beyond irritated by the useless misleading trivia that plagues the headlines to hype up the event.
This event will be amazing and special on its own, and it doesn’t need any further hype! As a dedicated observer and astrophotographer, I’ll do my part in hyping it through the pictures I share, and giving you the correct facts!
Remember that we call a Jupiter and Saturn conjunction a “Great Conjunction,” and believe it or not, in the grand scheme of time, they happen rather frequently – every 19-20 years. So every two decades or so, Jupiter, having the faster orbit of the two planets, will appear to “lap” Saturn in the sky as they continue their orbits around our Sun, and appear to shift their positions in the sky from west to east in front of the Zodiac constellations (save for retrograde motion but that’s a different matter).
When these Great Conjunctions happen, sometimes the planets will still appear about a “moon diameter” apart, other times further apart… and much more rarely close enough to be seen as a “double planet,” and this is due to Earth’s perspective, and each respective planet’s orbital plane in our Solar System not being 100% perfectly in line with each other.
So where do they get the “First Time in 800 Years” From?
Because on December 20/21, the two planets will officially be 6 arc-minutes away from each other, or a tenth of a degree. A better way of saying that is the two planets will be separated by 1/3 the diameter of a full moon away… so close you can cover both of them with your pinky at arms length!
And they were even closer on March 4, 1226… by about 2-3 arcminutes – about half the separation as we’ll see in 2020! So it’s safe to say that the two planets being that close is exceptionally rare, and one could say they’ll appear as a “Double Planet.”
But was 1226 the last time we witnessed a Jupiter/Saturn “Double Planet?” Nope! We actually had one as recently as 59 years ago!
Again, we’ve had nearly 400 Great Conjunctons happen between 1226 and 2020. Surely there were other Great Conjunctions that were exceptionally close and could be seen as “Double Planets,” right? Here are some examples:
On July 16, 1623… the two planets were about 5-6 arc-minutes away… so pretty similar to what we will see in 2020.… wait, that’s less than 400 years ago – NOT 800 years like NBC or CBS said! OOPS!
The 1842 and 1901 Great Conjunctions saw the two planets separated by about a “full moon length” away… not quite a “Double Planet” but still really close – close enough to see both of them through a telescope in the same view!!
And lastly, on February 18, 1961, the two planets were 14 arc-minutes apart, so about half the diameter of a full moon apart… Close enough to still be considered a “Double Planet” as it would have looked to the naked eye.
So yes, the headlines that say “First time in 800 Years” Are NOT Accurate! There were plenty of times the two planets appeared super close in recorded history before and after Medieval Times…
But that doesn’t mean this 2020 Great Conjunction won’t be amazing. It’s still going to be a once in a lifetime event, as stated before, it’ll be rare for them to be this close together! The 2040 and 2060 Great Conjunctions will have the planets appear one degree or “two full moon diameters” away, and will not appear exceptionally close again until the year 2080!
I will be looking forward to seeing the two gas giants in the telescope at the same time at 200-300x magnification! I’ll be looking forward to all the times I’ll be capturing these two planets together in my camera and sharing the event to the masses! I’ll be especially looking forward to the people who visit my telescope and see the Great Conjunction for themselves!!
If you’re reading this: Trust me, this is your one and only chance to see the pairing through a telescope at the same time. DON’T MISS OUT!
But Wait, you heard this is a “Jesus Star” or “Star of Bethlehem?”
Once again, it’s not entirely true but not entirely false.
Yes, Johannes Kepler in his observations thought that the Star of Bethlehem was such an occurrence. There was a very interesting one that occurred in 7 BC (-6 if trying to find it on star apps), which was actually a rare series of three conjunctions, as both planets were in retrograde at the time. Like two cars neck and neck on a race track, Jupiter appeared to “lap” Saturn in May, lose the lead in September, and then “overtake” Saturn again in December before “speeding off.” But they never appeared closer than a degree away from each other. The 2020 Conjunction will look much more impressive than what the Roman Empire saw in 7 BC!
Without going too much into it, there were a number of astronomical events that occurred in that proper time frame which could have been interpreted by Babylonian Astrologers (the Magi) as a heavenly sign indicating a Jewish prophecy was coming true. But there is still an ongoing debate between astronomers that will never get settled over which of these was indeed the Biblical star – and that’s if one believes it ever happened.
Something like this doesn’t need to be overhyped. It doesn’t need any special trivia. It just needs to be observed and witnessed! Get your telescopes out soon, or if you don’t have one, get in contact with someone who does!
Get Out There and LOOK UP!
NOTE: For those that don’t understand what “arc-minutes” are, you have degrees, arc-minutes, and arc-seconds… 60 arc-seconds is 1 arc-minute, and 60 arc-minutes is 1 degree, and the entire sky is 360 degrees across in a circle! For another reference, the Sun and Moon’s disc cover about 30 arc-minutes or half a degree across in the sky. Read This Article to further understand it better.