The phenomenon happens every 20 years, but the two planets were not so close since 1623.
“Not only are they the two largest planets in the solar system, they are also the two largest planets that we can see with the naked eye”, even though Venus is “brighter”, explains Pedro Garcia, communication technician at OASA.
20 years ago, in 2000, “these two planets were very close, to the point that we were able to put a little finger between the two, which is more or less a degree in the sky. This time, if we put a little finger, we will be able to cover the two planets, which means that it is really, really, very close ”.
In what would be “the highlight of the year”, OASA will not open doors, due to the restrictions imposed by the covid-19 pandemic, but the official leaves some suggestions for those who want to observe the alignment.
The ideal would be to use a telescope, but “with the naked eye” and “in a sky with very little light pollution and on a night with good weather conditions, it will be possible to see the two planets so close together that it will look like just one”.
Also binoculars, which “can even be playful”, can help. “If the binoculars are any size, 50×70, they will already be able to see the moons of Jupiter and realize that Saturn has ‘ears’, which are the rings”, guarantees the technician.
The phenomenon happens around 17:30 in the Azores (18:30 in mainland Portugal) but Pedro Garcia advises to start following the phenomenon from 15:30 (16:30 in Lisbon). “Starting at 7 pm, objects (planets) will be touching the horizon and will disappear throughout the night”.
As for its position, “the object will be seen in the southwest. After the sun goes down, more or less in the same position ”, he adds.
“As long as people have a good view of the sea, in the southwest, that has no mountains or houses in front, or light poles with light pollution, they will easily see this phenomenon”, he guarantees.
This, of course, if the weather cooperates. The Portuguese Institute for the Sea and the Atmosphere (IPMA) issued a yellow warning for all islands in the archipelago. At 17:30 on Monday, however, it is expected that only Santa Maria and São Miguel are still under yellow warning due to precipitation.
The two planets will form a point that resembles a star. Pedro Garcia clarifies that “one of the ways in which we perceive that it is not a star is because it does not sparkle, because the planets do not sparkle in the sky, but a very bright point will appear in the sky”.
With the approach to Christmas, and on the day of the winter solstice, this alignment is of particular relevance, since there are those who compare it with the star who guided the Kings: The astronomer and mathematician Johannes Kepler, in the 17th century, “ he suggested that what is described about the star of Bethlehem was a conjunction, but it does not seem to me to be any of that, not least because the effect will not be similar to the description of the star of Bethlehem ”, demystifies.
Symbolisms aside, the advice is that “whoever can do this [observar a conjunção], let him do it ”.
“Take advantage of the fact that this phenomenon will only happen again in about 60 years, in 2080, and, perhaps, this could be the last opportunity for many people”, says the official.
Despite being closed on that day, OASA will transmit images of this event online. But the technician reinforces: “I will be honest, these videos can be seen later, on the internet, what I advise is that, if the weather is good, go outside, use your cell phone, and you will see the phenomenon”.