June has been a more fascinating time astronomically than it may have seemed. For weeks we have had several opportunities to see a very rare planetary conjunction. Without the need for binoculars and shortly before twilight, Mercury, Venus, Mars, Jupiter and Saturn have been seen throughout the month. This is something that happens every 18 years and is about to end. Over the top, yes.
What is this about a ‘planetary conjunction’? The fact that two or more planets appear aligned in the sky is something relatively frequent: all the planets of the Solar System orbit in approximately the same plane with respect to the sun. Of course, this is an optical effect: seeing them up close does not mean they are “closer” to each other. It is, something very surprising, yes; but, in the end, it is a matter of perspective.
What exactly can we see? Although planetary conjunctions are frequent, those of these five planets are not so: Although, as I said, the conjunction has been seen since June 3, the truth is that as the month has progressed and the planets have been moving away del Sol, the outlook has been improving. Now the parade of planets can be seen in areas where the horizon is not necessarily clear in the east.
But things get much more interesting because on the 24th, coinciding with the night of San Juan, there will be one more guest: the Moon, which will sneak between Venus and Mars, in the place where the Earth would be in the order of the Solar System. . As I said, this is one of those phenomena that occurs every many years. The last time we saw it was in 2004 and we will have to wait until 2040 to see it again.
How to see it? The planets will be appearing in the east and moving towards the south (or towards the north for those observing from the southern hemisphere). Mercury will be the last planet to appear, completing the conjunction. While we’re past the days when Mercury and Saturn are at their closest distance (91 degrees), there’s now more time to see it: up to 45 minutes before sunrise.
Of course, those who have a sufficiently powerful telescope or binoculars will be able to double the bet and, according to astronomers, they will even be able to see Uranus and Neptune.