dark skies?
Are your skies dark enough to see the stars? A new map of the Milky Way is revealed just as the planets go on parade.
Dear word explorer,
Few things infuse me with more inspiration and hope than new discoveries about the workings of our star-stuffed universe.
I’m lucky to live in a relatively low-light rural location in the West of Ireland, and thanks to a couple of mobile phone apps (Stellarium is excellent), I can monitor the position of the planets and constellations, day or night, from my home or outside. It’s pretty cool to point your phone downwards and see the stars below your feet, as if you possess an X-ray device capable of peering through the planet!
Are you aware that Ireland is home to three Dark Sky regions? Ah, but I get ahead of myself… what is the Dark Sky initiative? The International Dark Sky Association (IDA) was established in 1988 by astronomers David Crawford and Tim Hunter, and its mission was to educate governments and people about the adverse effects of light pollution.
Thanks to the IDA, there are Dark Sky reserves and parks around the world that maintain low levels of light pollution to aid astronomical observation, safeguard nocturnal ecosystems, and protect access to our celestial cultural heritage.
In Ireland, the first designated Dark Sky region was the Kerry International Dark Sky Reserve. It’s situated on the Iveragh Peninsula in south-west Kerry, and covers approximately 700 square km. This Atlantic starry wonderland was honoured thanks to the dedication of the local community and their astronomy club, who recognised they lived in a low-light paradise and wanted to keep it that way. Due to the outstanding quality of its dark skies it was the first reserve to obtain Gold Tier status in 2014. It remains one of only four Gold Tier Dark-Sky Reserves in the northern hemisphere.1
This was quickly followed by the Mayo International Dark Sky Park at the Wild Nephin National Park in Co. Mayo, which was designated a Gold Tier park in 20162 and covers an area of 150 square km. It hosts the Mayo Dark Sky Festival every year in November.
The most recent is the OM Dark Sky Park and Observatory, which is approximately 15 square km, in Davagh Forest, at the foothills of the Sperrin Mountains in Northern Ireland. It was given a Dark Sky designation in 2020.
The sad fact is that the Milky Way galaxy, a glorious band of stars in our night sky, ‘is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans.’3 The following graphic offers a visual of the distribution of light pollution, which is tied to urban areas with the highest concentration of population.
The main culprit is skyglow, which is not a comic book villain, but the diffuse luminance of artificial light sources. From a distance it appears like a dome of light over towns and cities. For example, the skyglow from Dublin city on the east coast of Ireland is visible on the Llŷn Peninsula in Wales, approximately 113 km across the Irish sea.
This lingering light is disorientating for wildlife, especially the night-loving creatures, but it’s not beneficial for humans either. Not only are our splendid star vistas obscured, but artificial light disrupts sleep patterns, our circadian rhythms and has been connected to various health conditions.4
I can attest that it is far easier for me to sleep during the winter while it performs its deepest stretch of darkness.
If you live in a city and manage to travel to less densely populated areas, seize the opportunity to enjoy wandering under dark skies and observe the fully glory of the mesmerising stars!
But do you know who has had a stellar view of the Milky Way? The European Space Agency’s (ESA) Gaia craft, launched back in December 2013.
Since then it has been mapping a ‘precise three-dimensional map of more than a thousand million stars throughout our Milky Way galaxy and beyond, mapping their motions, luminosity, temperature and composition.’
Less than a week ago Gaia completed the sky-scanning phase, having made more than three trillion observations. Despite fading fuel reserves (and it has suffered a micrometeoroid hit and solar storm damage), the ESA hopes Gaia will be capable of more data transmissions.
As I’ve noted before, our space agencies don’t believe in early retirement for their interplanetary craft.
“This will conclude an incredible coordinated effort between hundreds of experts across the science operations centre here at ESAC, the mission operations team flying Gaia from ESA’s European Space Operations Centre in Germany, and the huge consortium of data processing specialists, who have together ensured the smooth running of this beautiful mission for so long.”
Once again, I’m impressed at how much collaboration takes place between scientific teams in many countries for these long space missions, which can take decades to complete, from planning through execution and the processing and analysis of the observation data.
I love that image of Gaia performing over 15,000 ‘pirouettes’, like some cosmic ballet dancer, entertaining a starry audience and monitored by its off-stage human crew.
Yet the original Greek goddess Gaia, is hardly a pawn. She’s the primordial mother, representing Earth, who created herself from the void of Chaos, and birthed the first set of gods, creatures and giants, including the god Uranus, with whom she had children (but Gaia had many offspring with many mates).
Several times her children and lovers became overbearing autocrats and she helped overturn them, or lent encouragement to those who would challenge the rule of bullies.
Kind mother and crafty rebel, she makes and unmakes.
She is no metal puppet.
She is the crucible and the fire.
For those of you who have access to dark skies, there’s a planetary parade sailing across our firmament at the moment. Venus, Saturn, Jupiter and Mars are all visible in the sky, with Uranus and Neptune lurking in the background if you have a telescope.
On the 28th of February Mercury will join them. From our Earth-bound perspective of the heavens it will be an uncommon gathering of big personalities.
Let’s hope they don’t serve the wine too early.
It is twinned with the Aoraki Mackenzie Gold Tier Reserve in New Zealand.
Late in 2024 it was given the International Dark Sky Place of the Year award from DarkSky International.
‘The new world atlas of artificial night sky brightness’ at Science.org, 2016.
I’d suggest you investigate via your handy search engine of choice, but it’s worth noting that the worst light pollution occurs in cities, which also have sound and air pollution, so I’d guess it’s not easy to separate out those impacts.