Editor’s Note: The renowned English astronomer, Howard Parkin, writes for us from the Isle of Man, a British Crown dependency. Aero Crew News will not change his spellings nor punctuation to American English.
Living as most of us do, primarily in one location on Earth, we tend to be aware of the seasonal nature of the night sky. Whilst this is valid, the labelling of “the seasonal nature of the sky” gives a distorted and inaccurate view of the night sky, especially if as aircrew, your work takes you from the northern to southern hemispheres on frequent occasions. We speak of the seasons most often about the effect of the seasonal changes brought about by the weather. We erroneously talk about “stars of winter, spring, summer, and fall” which is only valid if you are viewing the night sky from one specific location.
The more correct and precise titles would be to refer to “the stars of December, or June” etc. As the Earth orbits the Sun on its annual journey, we only see certain stars, in the evening hours as we look in the exactly opposite direction to the Sun. At any time of year, we will always see the same stars. For instance, we see the constellations of Orion, Taurus and Gemini in December through February, regardless of your location on the Earth. In the U.S. and the northern hemisphere, we see these dramatic and bright stars in the winter but in the southern hemisphere, it is their summer.
The ancient observers saw the paths of the planets as influencing our human existence on Earth which gave rise to the subject and study of astrology, strongly linking astrology to astronomy. However, in the sixteenth and seventeenth centuries, Copernicus, Kepler, Galileo, Newton, and others proved that the Earth goes around the Sun, contrasting the previously accepted theory that the Sun, Moon and other planets orbited the Earth. Consequently, the two subjects maintained their common link but went their separate ways.
The Earth’s axis is inclined at an angle of 23.5 degrees from the equator, and this tilt (or inclination) gives us the seasons. The path that the Sun, Moon, and planets appear to travel along throughout the year is an imaginary line in the sky called the ecliptic. The name derives from the world eclipsis and is the path along which eclipses can occur. The zodiacal constellations are the twelve constellations that sit on the ecliptic.
Consequently, one of the twelve zodiacal constellations on the ecliptic that the Sun passes through when you were born is your own individual birth sign. Consequently, your birth sign will not be visible at night when you celebrate your birthday. You only see your zodiacal sign about six months before (or after) your birthday.
However, due to the phenomenon known as the precession of the equinoxes, the dates that the Sun passes through your own birth sign are about a month out. For example, if you were born on 3 August, you have likely always thought your sign is Leo. But the Sun is still passing through the preceding neighbouring constellation of Cancer on that date. Furthermore, and to further confuse, there is a thirteenth sign of the zodiac, Ophiuchus (the Serpent Bearer, pronounced oh-fee-YOO-kus), which astrologers conveniently ignore. Strictly speaking, if you were born between 30 November and 18 December, your sign is Ophiuchus, not Scorpio. Use that in the pub!
The zodiacal constellations through which the Sun passes annually
On July 1 the ecliptic stretches across the sky from horizon to horizon, or more specifically, it meets the horizon at an angle of 305 degrees at sunset, and 63 degrees at sunrise. This is because the sun at its most northerly position at the time of the June solstice.
As you observe the night sky from the flight deck in July through September just before sunrise, it is possible to see the faint autumnal stars of Pegasus, Andromeda and Pisces, followed by the bright stars of Taurus and Orion. In the opposite direction just after sunset, you may see the setting spring constellations of Virgo and Libra. The constellations of Gemini, Cancer, and Leo will not be visible as the Sun passes through them in the July to September period and will thus be too near the sun for observation.
As well as the view of these constellations (after all the excitement of the “planetary parade” earlier this year), during July to September the Earth has moved on its orbit around the Sun, so Venus has now moved into the morning sky and is very bright and unmistakable in the dawn sky passing through the constellations of Taurus, Gemini and Cancer.
Finally keep your eyes peeled on the eastern horizon in mid-August as one of the best meteor showers of the year occurs on and around August 12. The Perseid shower is so named because it appears to come from the constellation of Perseus. Around this date, look for bright rapid shooting stars or meteors around the northeastern horizon.
Editor’s Note: If you’re home on or around this date, find a dark-sky place to observe Mother Nature’s fireworks and make memories with the children in your life. I so fondly remember watching this meteor shower with my grandfather. Every shooting star I see to this day reminds me of that night, that man and that night-sky show. -D
Look to the eastern horizon in mid-August for the Perseid meteor shower, which peaks around August 12. The shower, named for its apparent origin in the constellation Perseus,
is shown here during the 2024 display.
