We offer you the astronomy calendar for May 2019. Astronomy is the foundation upon which astrology can operate. Actually, astrology and astronomy were treated together, under the Latin name of astrologia, being separated only by the Western 17th century philosophy. One thing is sure: a good astrologer needs to study astronomy.
Saturday, May 4th: New Moon
The New Moon is when the Sun and Moon are aligned, with the Sun and Earth on opposite sides of the Moon. The new moon is the first lunar phase, when the Moon and Sun have the same ecliptic longitude. At this phase, the lunar disk is not visible to the unaided eye, except when silhouetted during a solar eclipse. This is the best time of the month to observe faint objects such as galaxies and star clusters because there is no moonlight to interfere.
Monday, May 6th, Tuesday, May 7th: Eta Aquarids Meteor Shower
The Eta Aquariids are a meteor shower associated with Halley’s Comet. The meteors we currently see as members of the Eta Aquariid shower separated from Halley’s Comet hundreds of years ago. The current orbit of Halley’s Comet does not pass close enough to the Earth to be a source of meteoric activity. The Eta Aquariids get their name because their radiant appears to lie in the constellation Aquarius, near one of the constellation’s brightest stars, Eta Aquarii. The shower peaks at about a rate of around a meteor per minute, although such rates are rarely seen from northern latitudes due to the low altitude of the radiant. In the Northern Hemisphere, the rate can reach about 30 meteors per hour. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Aquarius, but can appear anywhere in the sky.
Saturday, May 18th: Full Moon and Blue Moon
The full moon is the lunar phase when the Moon appears fully illuminated from Earth’s perspective. This occurs when Earth is located directly between the Sun and the Moon (more exactly, when the ecliptic longitudes of the Sun and Moon differ by 180°). This means that the lunar hemisphere facing Earth – the near side – is completely sunlit and appears as a circular disk, while the far side is dark.
This moon has also been known as the Full Corn Planting Moon and the Milk Moon.
Since this is the third of four full moons in this season, it is known as a blue moon. The previous blue moon was on May 21st, 2016. The next blue moon will be on August 22nd, 2021. This is valuable if we have in mind the astronomical definition of the blue moon: the third full moon in a season of four full moons, but referenced to astronomical rather than equal seasons.
There is one other definition of the blue moon, which depends on the Gregorian calendar and time zones. According to it, the blue moon is the second moon in the same calendar month.