This Thursday, May 31, 2017 there has been a curious phenomenon that has popularly been called “Blue Moon”. Do not be confused, the Moon will not look that color or be eclipsed, as it is circulating wrongly through some news sites. It is simply called a second full moon that takes place in the same month.
This phenomenon occurs more or less every 2 and a half years, and is basically related to the orbital period of our satellite around the Earth. As we well know, the Moon takes the same time to revolve around itself and its translation around our planet (27 days); this implies that we always see the same "face", and according to the position in which it is in relation to the Sun is that we will see its "phases", that is, different visual aspects of the Moon according to the portion that is illuminated (Fourth Crescent, full moon, new moon, etc.)
But the following must be taken into account: the orbital period around the Earth (27 days) corresponds to the sidereal revolution (taking into account the turn in relation to the star background), but its synodic revolution (taking into account the turn in relation to the Sun) is 29 days. The synodic revolution, then, is what determines the phases of the Moon that we see in a month. But since the months have 30 or 31 days, this lag implies that at some point it is possible to have the configuration of having 2 full moons in the same month. Thus, this month he had his first full Moon on May 2; and she will have her second on May 31, when we will see her emerge in the East around 9:40 p.m. * (6:40 p.m. local time). Blue? The second full moon of the month of May will be seen just like any other; a very bright pearly gray color. There are different versions about the origin of the Blue Moon denomination, but these are the most popular: - Within the ancient American traditions, farmers used to use colloquial denominations to refer to the full Moon under which they collected their crops that, according to belief, were more productive when picked up at night instead of day. When performing these works on a full moon, its reflected light seems to give the ground a medium blue tinge. - The thirteenth full Moon in a year was known, this time according to the Christian religion, as "the saddest" or "the rarest." This tradition may have to do when associating the thirteenth (13th) Moon with a number of bad luck; or because because this extra full moon did not have an exclusive month to assign it, it was a "sad moon" or "blue moon" (the translation is homologous in English for "blue moon", "single moon" or "rare moon". - Krakatoa volcano erupted in 1883. The explosion was so great that it was heard more than 500 kilometers around, and the furious volcano threw a huge column of ashes into the high atmosphere.These small particles created an effect of scattering of the red light, while allowing other colors to pass in. Thus, the light of the bright full Moon at that time acquired a bluish tint. The Moon turned blue (and the effect lasted even several years because of the effect of the ashes in the atmosphere.) In summary ... Prepare to observe the second full moon of May 2007 !. It will be a beautiful show, considering that for that night our satellite will be locate as well the 7 of the planet J piter, and will be found hiding the bright star Antares from the constellation of Scorpio, which will appear again on the other side at approximately 23:22 UT (20:22 local time)! So be sure to see our satellite. Red, blue, green or yellow, always offers us a show worthy of observation by any fan. * UT: Universal Time.
