About 800 years ago in 1226 two planets “aligned” visually to the night sky. It was the union of Jupiter and Saturn. In a rare event, they appeared extremely close together at 1/15 of the moon’s apparent width.
It took place on 4 March 1226 – a few months before the death of Francis of Assisi to give you an idea of the time frame. It was also the 20th year of Genghis Khan’s reign and one year before his death in 1227.
While 1226 was the last time a very close conjunction between Saturn and Jupiter, this was not the last time. In fact, the conjunction between Jupiter and Saturn occurs every 19.6 years. Due to the angle at which both Jupiter (1.3 the) and Saturn (2.5 both) revolve around 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 more rare that we see a combination that is less than 1 more.
In 2020 we get to see one of the rare Close A combination of encounters, tenths of a degree. To find a similar combination in 2020, apart from 1227, you have to go back to the 17th century.
In the summer of 1623, Galileo was enjoying the telescope he had built 14 years earlier, in 1609. Little did they know that a combination of planets was occurring. Even if he knew, he would not have seen. This planetary alignment occurred within 13º of the Sun and therefore it was not visible from Earth. Sad day for Galileo.
Now, in 2020, we will get to see this spectacle in the coming weeks. If you look at each night, you will see two planets close together each evening.
The “Great Conjunction” as it is being said, will eventually occur on the night of the winter solstice.
This is right! Incidentally, at the beginning of the longest night of the year we will see that the two planets will appear separated by a tenth of a degree (0.1 a). This is about one fifth the diameter of the Moon!
When looking through a telescope or binoculars, you will likely see both Saturn and Jupiter in the same frame (already rare) as well as their moons!
Of course, while these two gas giants would “appear” together, they would still be hundreds of millions of miles apart. Jupiter is about 545 million miles from Earth, and Saturn is another 455 million miles away.
Jupiter is the largest planet in our solar system and will be the brightest. There will be a golden color for Saturn.
When these two planets “meet” on December 21, be sure to watch during the mist and just after the sun sets. These two planets will “set” very quickly and you don’t want to miss it! Look to the west.
Some people have called this meeting a “Christmas Star” because on December 21, two planets together will appear so big and bright. However, I will note that both astronomers and biblical scholars have determined the star of Bethlehem during the birth of Jesus, which could not have occurred as a conjunction between Jupiter and Saturn, to a degree during that time It must have been about half, or about the width of the moon, and therefore not so bright. Definitely not as bright as we are seeing on 21 December. Also remember that this event can happen at any time of the year, not just during December. It all depends on the cycle of 19.6 years.
While the event will also occur in 2040 and 2060, it will not be until March 15, 2080 that they will be visible again, or maybe just a closer than we get to see in 2020.
If you see Christmas Star on December 21, be sure to send us your photos via the KOMU 8 Weather app!