Almost 800 years ago, in 1226, two planets visibly “aligned” in the night sky. It was the conjunction of Jupiter and Saturn. In a rare event, they appeared extremely close, 1/15 of the apparent width of the Moon.
This happened on March 4, 1226 – just a few months before the death of Francis of Assisi to give you an idea of the time period. It was also the 20th year of Genghis Khan’s reign and a year before his death in 1227.
Although 1226 was the last time an extremely close conjunction between Saturn and Jupiter was visible, it is not the last time it has happened. In fact, the conjunctions between Jupiter and Saturn happen every 19.6 years. Due to the angle at which Jupiter (1.3º) and Saturn (2.5º) both orbit the Sun, when they meet every 19.6 years they will be at different distances from each other, anywhere from 4º or less. Therefore, it is even rarer to see a conjunction less than 1º.
In 2020 we will see one of the rarest hang up meetings, a conjunction of a tenth of a degree. To find a close conjunction similar to that of 2020, in addition to 1227, you must go back to the seventeenth century.
In the summer of 1623, Galileo enjoyed the telescope he had made 14 years earlier, in 1609. He did not know that a conjunction of planets was happening. Even if she knew, she wouldn’t see him. This planetary alignment occurred at 13 ° from the sun and was therefore not visible from Earth. Sad day for Galileo.
Now, in 2020, we will see this show in the coming weeks. If you look every night, you will notice that the two planets are approaching every night.
The “great conjunction,” as it is called, will finally take place on the night of the winter solstice.
This is right! Coincidentally, at the beginning of the longest night of the year we will see two planets appear separated by a tenth of a degree (0.1º). This is about a fifth of the apparent diameter of the Moon!
When looking through a telescope or even through binoculars, you will be able to see both Saturn and Jupiter in the same frame (already a rarity), as well as their moons!
Of course, while these two gas giants will “appear” close together, they will still be hundreds of millions of miles apart. Jupiter is almost 545 million miles from Earth, and Saturn another 455 million miles beyond.
Jupiter is the largest planet in our solar system and will shine the brightest. Saturn will have a golden hue.
When these two planets “meet” on December 21, be sure to watch them at dusk and even after sunset. These two planets will “settle” pretty quickly and you don’t want to miss it! Look west.
Some have called this meeting the “Christmas Star” because the two planets together on December 21 will appear so big and bright. However, I will note that both astronomers and biblical scholars have determined that the star of Bethlehem at the time of Jesus’ birth could not have been a conjunction between Jupiter and Saturn, because a conjunction at that time would have been only about half a degree. or about the width of the moon and therefore not so bright. Of course, not as bright as we’ll see this December 21st. Also remember that this event can take place at any time of the year, not just in December. It all depends on the 19.6 year cycle.
Although this event will take place in 2040 and 2060, it will not be until March 15, 2080 that they will be visible again so close, or maybe even a little closer than we will see in 2020.
If you see the Christmas Star on December 21, be sure to send us the photos via the KOMU 8 weather app!