Skymatters: Get ready for winter solstice - and the 'king of the meteor showers' - in December
![Skymatters: Get ready for winter solstice - and the 'king of the meteor showers' - in December Skymatters: Get ready for winter solstice - and the 'king of the meteor showers' - in December](/cms_media/module_img/7724/3862084_3_articlesmall_22169371-1.jpg)
Newgrange, Co Meath
The most notable astronomical event in December is probably the winter solstice. It’s that time of year when the days start to become longer again, when the apparently inexorable lengthening of the nights that started on June 21 is reversed.
It represents the promise of brighter and warmer days to come. It has a psychological impact for us in our modern world, but for our ancestors, the impact was more than psychological.
The solstice was monumental, of such significance they literally built monumental structures to mark the event.
![An aerial view of the megalithic tomb at Newgrange. Pic: Copter View Ireland An aerial view of the megalithic tomb at Newgrange. Pic: Copter View Ireland](https://www.irishexaminer.com/cms_media/module_img/7719/3859510_7_articleinline_Newgrange_20Early_20Morning_20-_20Copter_20View_20Ireland_20_1_20of_201_1_.jpg)
Many of these structures would have consumed enormous resources in these early communities. The best example is probably Newgrange, Co Meath, a magnificent passage grave aligned to the rising Sun.
It seems reasonable to imagine that our ancestors associated life with the Sun’s warmth. They weren’t wrong. Without the Sun the Earth would be a permanently frozen rock.
But the Sun is not the only celestial object which has been crucial to life on Earth. Some of the smallest objects in our solar system have been every bit as important.
These are comets and asteroids. Their role was to bring water to the early Earth at a time when it was dry and hot.
They also brought carbon, which is fundamental to our biology, and molecules which we use in building the proteins that have enabled us to evolve from simple, microscopic lifeforms, to become incredibly complex humans.
When the Earth was young, about 4.5bn years ago, the number of comets and asteroids would have been mind-boggling.
The Earth would have been hit frequently with impacts of such ferocity that they would have caused the dinosaurs to become extinct.
But this was an era about 4bn years before dinosaurs appeared, before even the simplest forms of life appeared.
As time passed the number of comets and asteroids declined, until we reach modern times when big impacts are incredibly rare, with a frequency measured in tens or hundreds of millions of years.
And yet small impacts persist. These come from debris ejected by today’s much smaller comets and asteroids in the form of particles usually the size of a grain of sand. They can be seen in our skies as rapid flashes of light: shooting stars or meteors.
On December 14 each year, the dust from asteroid 3200 Phaethon (only discovered in 1982) provides us with a display known as the Geminid Meteor shower.
This year the Moon will have set by the time it gets dark, so from around 7pm onwards conditions will be excellent for viewing, possible clouds notwithstanding.
The Geminids are often considered to be the King of the Meteor Showers with up to two meteors per minute visible from dark skies.
Many of these are multicoloured, possibly reflecting the fact that they contain complex molecules that glow differently as they disintegrate in the high-speed collision with the Earth’s atmosphere.
The best way to observe the Geminids is simply with the unaided eye.
They can appear anywhere in the sky, at any moment, and if you give your eyes about 20 minutes to adapt to the dark you’ll be able to see more of the fainter meteors and more of the colours of the brighter ones.
Avoid, at all costs, the use of mobile phones: even the night-sky apps that are free to download and really helpful to identify your way around the sky will adversely affect your night-sky vision.
And given that you don’t actually need to look in any particular direction to see the Geminids I would suggest you simply sit or lie down and gaze upwards (while keeping warm, of course!).
Our ancestors would have also seen the Geminids, a mere week before the annual solstice, but it seems unlikely that they would have made any association between them and life.
Perhaps they were impressed anyway. Perhaps thoughts of the solstice dominated. For us, it’s time to put both phenomena on something of an equal footing.