Stargazing in August: The many names for the moon

This month, we’re treated to a sturgeon moon, a blue moon, and two supermoons. Or, according to other traditions, a lightning moon, a dispute moon, a dry moon and – confusingly – a red moon!

These are all names given to the moon when it’s full, and at its maximum brilliance. Before our skies were filled with artificial illumination, the full moon made a huge difference to people’s lives, letting them work later into the evenings and easily find their way around at night. And so it was natural for them to distinguish the successive full moons of the year.

Many traditions around the world gave colourful names to each full moon of the year, but it’s the names from North America that are most widely used today. Most people go by a list compiled by the Old Farmer’s Almanac, first published in 1792:

January: Wolf Moon

February: Snow Moon

March: Worm Moon, when earthworms emerge in the warming soil

April: Pink Moon, named after the moss pink flower

May: Flower Moon

June: Strawberry Moon

July: Buck Moon, when the male deer’s antlers are growing

August: Sturgeon Moon

September: Harvest/ Corn Moon

October: Hunter’s Moon

November: Beaver Moon

December: Cold Moon

The full moon a few days ago – on 1 August – was the sturgeon moon, when North America’s largest freshwater fish are abundant in the Great Lakes and fishermen were assured a bumper catch.

In South Carolina, the rivers and streams dwindle in the summer heat, so the August full moon was named the Dry Moon. Many birds moult at this time, and the Arapaho people of the American plains called it the Geese Shedding their Feathers Moon.

To the Celtic tribes in Europe, the August full moon was the Dispute Moon: over the first fruits of the harvest, and with copious mead flowing, people feasted together and resolved their long-standing arguments.

Elsewhere, this full moon was hailed as the Lightning Moon, due to the fierce storms that were stoked by the summer heat. And the heat haze created during the day often led to the moon looking distinctly copper-coloured as it rose, creating the Red Moon of August.

And that’s not all: this month, we can look forward to a second full moon, on 31 August. With the traditional names taken by the previous full moon, this one is widely known as a blue moon.

The name is nothing to do with its colour: the lunar orb will appear just as white as any other full moon. It derives from the phrase “once in a blue moon,” as it’s only once in every two or three years that we witness two full moons in the same month.

The ‘blue moon’ tag wasn’t devised by astronomers, but again comes from an agricultural annual publication – in this case, the Maine Farmers’ Almanac (1819-1968). When there were four full moons in a three-month season, this almanac listed the third of them as a ‘blue moon.’

But in 1946, a writer in the prestigious astronomy magazine Sky & Telescope misinterpreted the almanac as describing the second full moon in a calendar month as a ‘blue moon.’ This usage caught on universally after it became an answer in the popular quiz game Trivial Pursuit, in 1986.

And both full moons in August are also ‘supermoons’ – a term again not invented by astronomers, but in this case by Richard Nolle, an astrologer. A supermoon is a full moon that’s unusually close to the earth in its orbit, so it appears bigger and brighter in the sky. The usual definition is that a supermoon is closer than 90 per cent of the moon’s average distance from the earth, and this means that are three or four supermoons every year.

In 2023, there was a supermoon last month; the two in August; and the full moon in September, with the ‘blue moon’ of 31 August being marginally the closest of the four. Even so, ignore anything in the popular media suggesting the full moon will appear extraordinary that night: it will look only 14 per cent larger, and 30 per cent brighter than the dimmest full moons of the year.

Saturn appears as a steadily shining beacon low in the southern sky, in a region devoid of bright stars. The sixth planet reaches its closest point to Earth on 27 August, at a distance of 1311 million km. The Moon lies nearby on the night of 30/31 August.

Through a telescope, you can spot Saturn’s famous rings, and its largest moon Titan, which has an atmosphere thicker than the Earth’s air and is completely enveloped in orange clouds.

After 11pm, Jupiter steals Saturn’s thunder, when the giant of the Solar System rises in the east, shining 15 times more brilliantly than the ringed planet. The Moon is near Jupiter in the early hours of 8 and 9 August.

High in the south, three bright stars mark the corners of the Summer Triangle: Vega, Deneb and Altair. On a dark night, you can spot the glowing band of the Milky Way flowing between these stars and down towards the southern horizon, to the left of the red giant star Antares. In the other direction, to the north, the Milky Way passes through W-shaped Cassiopeia and Perseus.

And Perseus spring to life this month, as shooting stars rain outwards from the constellation. These meteors are fragments from Comet Swift-Tuttle smashing into the Earth’s atmosphere and burning up high over our heads. Though the Perseid meteor shower is an annual fixture in the astronomer’s calendar, this is an unusually fine year for observing them as the Moon is well out of the way and its light doesn’t spoil the show.

The Perseid shower peaks on the night of 12 August, though you’ll catch some meteors before and after that date. Find a place away from streetlights and other artificial illumination, stretch out on a lounger and look upwards (the meteors can appear anywhere in the sky as they streak away from Perseus), for the summer’s best display of cosmic fireworks.

Diary

3 August: Moon near Saturn

8 August, 11.28 am: Last Quarter Moon near Jupiter

9 August, early hours: Moon near Jupiter

10 August: Mercury at greatest elongation east

12 August: Maximum of Perseid meteor shower

16 August 10.38 am: New Moon

18 August: Moon near Mercury and Mars

21 August: Moon near Spica

24 August, 11.07 pm: First Quarter Moon near Antares

27 August: Saturn at opposition

30 August: Moon near Saturn

31 August, 2.35 am: Full Moon, supermoon, ‘blue moon’

Nigel Henbest’s latest book, ‘Stargazing 2023’ (Philip’s £6.99) is your monthly guide to everything that’s happening in the night sky this year