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The Back Garden Moon Starer

Humans have always gazed in awe at the night sky. In the last 500 years, we have slowly discovered that we live in a Universe so enormously vast, so utterly ancient, and containing such strange and wondrous objects, that it boggles the mind. We are truly lucky to live in times when we have such knowledge.

But this article is about an older, simpler astronomy. I will talk about the heavenly bodies in our galactic back garden — the Sun, Moon and planets that make up our solar system. These celestial neighbours can be seen, with no equipment, from our own back gardens.

By the way, the phrase "moon starer" is an anagram, but I'll come back to that later.

The Sun

It might seem an odd place to start, but understanding the Sun's movements will really help you to find the Moon and planets. Almost certainly you already have a good idea of where the Sun rises and sets throughout the year in your location. You can consolidate this knowledge on all but the cloudiest of days. Notice that at the equinoxes, 21st March and 21st September, the Sun rises exactly due East and sets exactly due West: this is true no matter where in the world you live. See how high he rides at the Summer solstice on 21st June (or 21st December in the Southern hemisphere). See, if you can! how low at the Winter solstice.

All these different places where the Sun may be through the day and through the year make up the ecliptic, sometimes called the "road of the Sun". It is also the road of the Moon and planets. The visible part of the ecliptic is an enormous semicircle through the sky: from somewhere in the East, through the South — sometimes high, sometimes lower — to somewhere in the West. (As usual, change "South" to "North" in the previous sentence if you are South of the equator.) And the rest of the ecliptic is another enormous semicircle below the horizon. You are at the centre!

Now, here comes a crucial point which may take a little while to get your head around. Although the ecliptic is the road of the Sun, he travels along it imperceptibly slowly, just 1 degree each day, taking a whole year to complete the circuit. The movement of the Sun that we perceive every day is the ecliptic itself spinning around the Earth. Every day, that enormous circle of the ecliptic spins from East to West, a complete circuit in just under 24 hours, carrying the Sun, the Moon, the planets and stars with it. (Of course, we understand that in truth it is the Earth that rotates, but it looks like the sky is spinning!)

Furthermore, the ecliptic sweeps up and down between high, low, and back again on each circuit. In fact, any particular point on the ecliptic is always at the same height as it tracks from East to West each day. In Winter, the Sun is at his lowest, because he is on that part of the ecliptic which is low every day. A Winter full moon — on the opposite side of the ecliptic to the Sun — is very high in the sky. Whenever you are outside, day or night, try to find the ecliptic. This is especially rewarding when you can see and recognise several planets, strung out along it.

Before we move on from the Sun, let me mention that his metal is gold; Greek Helios is identified with Roman Sol, also known as Apollo, the perfection of male beauty.

The Zodiac

The ecliptic is divided into 12 equal-sized segments: the zodiac. The segments are named Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. Astrological terminology is fairly straightforward. I was born with the Sun in Scorpio, and the Moon in Libra, with Taurus in the ascendant. This tells you within which segments of the ecliptic the Sun and Moon were at that time. The ascendant is simply whichever segment is rising on the eastern horizon; since the entire ecliptic spins around us each day, the ascendant sign changes every 2 hours.

But astrology is not as useful to the back garden moon starer as you might hope. The zodiac signs bear the same names as 12 star constellations which ring the ecliptic, but the signs and constellations no longer coincide. Due to the precession of the equinoxes — basically a 26,000 year wobble in the Earth's axis — the "first point of Aries" is currently in the constellation of Pisces! If your astrologer's ephemeris tell you that Mars is in Virgo (the sign), you'll actually see him in Leo (the constellation).

Moreover, the zodiac constellations are mainly rather unimpressive: nowhere near as striking as Orion (everyone's favourite constellation), or the Plough. Of the twelve zodiac constellations, Leo is the best — you will see him in late winter and spring, directly below the base of the the Plough's saucepan; due South as Orion sets. The colon (:) formed by the two stars Castor & Pollux, the twins of Gemini, is above and to the left of Orion. The very bright reddish star above and to the right of Orion is called Aldebaran and represents the bull's eye in Taurus. Spica is another bright star in Virgo, to the left of and below Leo. The remainder of the zodiac is unremarkable.

Finally, the one piece of astrological information that everybody knows is their Sun sign. But you can never see which constellation the Sun is near: if you can see the Sun, it's daytime and there are no visible stars!

The Moon

Each lunar month follows the same pattern, and I will describe this pattern starting from the new moon. It will be very helpful to have a calendar that shows new moons. Some lunar calendars are suggested at the end of this article. But you don't need much detail to start moon staring: the basic signpost of the new moon is shown in almost every calendar and diary.

But this brings us straight up against an unfortunate discrepancy: the new moon marked in calendars is invisible! In daily life, the new moon means the first sighting of the Moon, which is possible, weather permitting, 2 or 3 days after the astronomical new moon. So if your calendar shows a new moon on Monday, you might first see it on Wednesday, or more likely Thursday. Just after sunset, in the gloaming, look to the West, to the lightest part of the sky. The thin crescent of the new moon will set soon after the Sun.

Probably you will also be able to see the rest of the Moon's disc, very palely lit, by light reflected from the Earth. This is called earthshine, or "the new moon with the old moon in her arms", considered a portent of terrible weather. As the brightly lit crescent grows over the next few days, it masks the dim earthshine.

Each day, the Moon sets a little later (about 49 minutes) as she pulls away from the Sun. So the waxing crescent moon becomes easier to see each evening, being both brighter and visible for longer. A week or so after the astronomical new moon is first quarter, when the crescent becomes a semicircular D (in the Northern hemisphere). The first quarter moon is visible all evening, setting around midnight, and is highest in Spring, lowest in Autumn.

Past first quarter, the moon is gibbous (the g is hard), referring to its uneven shape. In late afternoon, you might see the waxing gibbous moon in the day time, newly risen in the East. She will not set till after midnight.

The full moon truly is the Queen of the Night. Now opposite the Sun on the ecliptic, she rises at sunset, reaches her maximum height at midnight, and sets at sunrise. The full moon is highest in Winter, and lowest in Summer. Your calendar will give the date of the astronomical full moon, but you will see a full, round disk for 3 nights around this date. On a clear night, away from street lighting, the full moon almost does "shine as bright as day". Even when it's cloudy, there's enough light to travel on foot or horseback. So festivals, moots, and all kinds of gathering were traditionally held at full moon. It is hard to imagine how significant the extra light must have been before urbanization.

The second half of the lunar month is a mirror image of the first half. The waning gibbous moon continues to rise later and later each night, and you may see it in the blue morning sky setting in the West. By last quarter, moonrise is around midnight. The last quarter moon is highest in Autumn, and lowest in Spring.

In the Northern hemisphere, the last quarter moon has a C shape, and you might find that DOC is a useful mnemonic for the whole cycle. (As you travel towards the equator, the Moon's bowl increasingly lies on its base. UOU isn't very helpful, but in the Southern hemisphere COD does the job.) At any time of the month, the round side of the Moon points along the ecliptic, towards the Sun.

A few days before the new moon, early risers may glimpse the crescent moon in the lightening sky before sunrise — a sight as beautiful as the new moon. Finally, for 3 or 4 days around the astronomical new moon, she is too close to the Sun, and cannot be seen at all. This dark moon period is ideal for inward magic; it is also a good time to see stars, planets, meteors, and sights which may be obscured by the Moon's light.

The metal of the Moon is silver. Roman Diana is identified with the Greek Selene, although the dark moon belongs to Hekate.

The Planets

There are five planets that can be seen with the naked eye. By now, you should have a good idea of where the ecliptic runs in the sky — all the planets are always on the ecliptic. The planets resemble stars, but there are two telltale differences: planets do not twinkle; and, although they are still just points of light, they are slightly larger than the pinpricks of the stars. These clues are subtle, but unmistakable with practice.

Planets are the "wandering stars", but don't expect to see them moving. If you note where a planet is relative to nearby stars, and then look again next week, you might be able to detect the difference. Mars is the best candidate for this. The Moon moves much more quickly than any planet, and you can see her motion along the ecliptic against the background stars in the course of an evening, but it's still like trying to see movement in the hour hand of a clock. (Comets don't go any faster, either. Apart from the brief streak of a meteor — a shooting star — if you can see it moving, then it must be an aeroplane, or perhaps a satellite.)

Venus is far and away the easiest planet to see. She is the third brightest object in the sky — after the Sun and the Moon — and yet her silver brilliance is often missed. Because her orbit is inside the Earth's, she is always somewhere near the Sun. This means that you will see her in the same places that you can see a thin crescent Moon — either in the West around sunset, or in the East around sunrise. Beautiful Roman Venus is identified with Greek Aphrodite, and Norse Freya. Her metal is copper.

Mercury is much closer to the Sun than Venus, and smaller. He can be seen with the naked eye in evening or morning twilight, but only for a few minutes of the day, for a few days, every seven weeks or so. Swift messenger of the gods, the Roman Mercury is identified with the Greek Hermes, and the Anglo-Saxon Wodin. His metal, of course, is mercury, also known as quicksilver.

Venus and Mercury are constrained to being near the Sun, so can only be seen in the evening or the morning, never in the middle of the night. Not so the outer planets: Mars, Jupiter, and Saturn. They can be anywhere on the ecliptic, and they travel quite slowly along it. Mars takes 2 years, Jupiter 12 years, and Saturn 30 years to complete an orbit. For Jupiter and Saturn, this means that once you have found them, they will be visible near the same stars for several months, earlier in the night each month. Then the Sun will catch them up and they will disappear for a few months; at this time they are only above the horizon during the day. And then they reappear before dawn, only a little further along the ecliptic than the previous year.

Mars moves more quickly, so it takes the Sun longer to catch him. This means that he stays visible at night for longer than Jupiter or Saturn — about a year — then disappears altogether for nearly another year. Mars is usually brighter than any star and is distinctly red. The god of war, Roman Mars is identified with Greek Ares (son of Zeus and Hera, not Aries the Ram), and Anglo-Saxon Tiw. His metal is iron, and his red colour is in fact caused by iron oxides (rust) in the dust storms that sweep over the surface of the planet.

Distant Jupiter is like a dimmer version of Venus: white and brighter than any star. Jupiter is the largest of the planets, and is a "brown dwarf" — almost, but not quite, a star. About half the light we see from Jupiter is reflected sunlight, but the other half is his own glowing heat. Leader of the gods, the Roman Jupiter or Jove is identified with the Greek Zeus and Anglo-Saxon Thor. His metal is tin.

Although almost as large as Jupiter, Saturn is much further away still. This means that he is no brighter than many of the stars. Slightly yellow in colour, he's not hard to see, just difficult to distinguish from the starry background. Remember, planets don't twinkle! Father of the gods, the Roman Saturn is identified with Greek Kronos, who is Time. His metal is lead.

There are three more planets that you won't see from your back garden. In theory, Uranus can sometimes be seen with the naked eye, but you'd have to know exactly where to look, and then use binoculars or a telescope to confirm that you'd got it right. There is no evidence that Uranus was known to the ancients (who spent plenty of time looking at skies clear of air- and light-pollution), or indeed anyone before 1781. Neptune always requires optical aid, and Pluto — much smaller — a decent telescope.

Conclusion

I hope that this brief tour of the Solar system will help you to find, recognise, and follow the movements of our planetary neighbours. Perhaps also I have made some links from astrology to what you can see when you look up on a clear night.

One lifetime is not enough to learn all the secrets of the starry skies. I have found that, with any lore, the best way is to increase your knowledge gradually. I try to learn the names of a few stars (and a few trees, and a few plants) each year. I don't seem to have reached the end of this quest just yet.

By the way, the phrase "moon starer" has the same letters as "astronomer"!

References & Resources

The following books and websites are good references if you wish to pursue amateur astronomy.

The Stargazer's Alamanac, published annually by Hawthorn. A large wall calendar with monthly maps of stars and planets, plus information on meteor showers, eclipses, and other things to see in the night sky.

The Monthly Sky Guide, by Ian Ridpath and Wil Tirion, Cambridge 2009. With 5 years of planetary positions, this guide sees a new edition every few years. It features very clear monthly star maps, and will soon have you saving for a small telescope.

Philips' Planisphere, published by George Philip and Son. A pair of rotating plastic disks that show the stars (but despite its name, not the planets!) for every day of every year. Easier to use than most of the printed star maps I've seen.

heavens-above.com I haven't looked at many amateur astronomy websites, but this one seems to be quite well-respected.

In writing this article, I also referred to the following books.

  • Hearth Witch by Anna Franklin, Lear 2004. 9780954753412.
  • Moonwise Diary by William Morris, published annually by Edge of Time. See moonwise.co.uk for details.
  • Earth Pathways Diary edited by Glennie Kindred, published annually by Moonshare Co-operative. See earthpathwaysdiary.uk for details.
  • The Times Night Sky, published annually by Times Books, but unfortunately not since 2007.
  • The NASA Atlas of the Solar System by Ronald Greeley and Raymond Batson, Cambridge University Press 1997. 9780521561273.
  • Brewer's Concise Dictionary of Phrase and Fable edited by Betty Kirkpatrick, Helicon 1995. 9781859862865.
  • World Ephemeris for the 20th Century by Para Research, 1985. 0914918613.
  • eclipse.org.uk Essential website for eclipse watchers.
Toby Goodwin
March 2010

This article was originally published in Silver Wheel anthology, edited by Anna Franklin.