Man with headlamp looks up at stars

Health benefits of dark skies

Today’s blog comes from our Healthy Parks Healthy People Coordinator Sarah McMichael. 

My most memorable camping memory didn’t come from a crackling campfire, a panoramic lookout, or a stunning sandy beach.

It happened at 3:00 am at Lake Superior Provincial Park.

As I stumbled out of my tent for a late-night bathroom break, I noticed something different about the sky above me. There were stars.

A LOT of stars.

In fact, I don’t think I’ve ever seen so many stars at once.

Lake Superior Rabbit Blanket Lake starscape
Photo: Paula Trus

At that moment, I was struck with a sense of wonder at the pristine darkness of the sky and the seemingly endless kaleidoscope of celestial objects above me.

I couldn’t look away.

There’s nothing like the feeling of staring up at a sensational starry sky. But beyond our positive feelings, dark skies are good for the health of humans, animals, and the environment alike.

Let’s look at some of the health benefits of dark skies:

Human health benefits

We’ve all seen the familiar ambient glow of city lights along the skyline. It’s called light pollution, and it’s caused by artificial lights from urban centres filling the normally dark night skies with light.

Lit up tent in trees at night

When we get away from cities and into natural spaces like provincial parks, the skies get much darker. This is good for our health for several reasons.

Over millions of years on Earth, the human body has evolved by experiencing  light during the day and darkness at night. This is also known as a circadian clock or rhythm.

This clock affects our physiology in many ways, including sleep patterns, hormone release, eating habits and digestion, and body temperature.

Having an irregular circadian clock has been linked to various chronic health conditions, including sleep disorders, obesity, diabetes, depression, bipolar disorder, and seasonal affective disorder.

Three men sit around campfire on rock

Have you ever noticed that you sleep better when camping? This is because we are exposed to more darkness at night.

Being exposed to artificial light at night breaks the circadian clock, while being in the darkness resets it. When camping, the darkness of the park is actually helping our circadian clock function more naturally. A better circadian clock means a better sleep, which contributes to better overall health.

When we sleep, we produce melatonin. This is a cancer-fighting chemical best produced in the dark. Some studies are beginning to see connections between light pollution and rates of cancer.

It’s not just good for us!

Darkness is important to the survival of many other species as well.

Northern saw-whet owl
Northern Saw-whet Owl

Many species have evolved to rely on uninterrupted periods of darkness at night. For example, nocturnal animals like bats, wolves, and owls rely on darkness to survive.

Seasonal changes in how long it is dark at night help plants prepare for spring and fall. They also provide important signals to other animals that trigger events like amphibian breeding and bird migration.

Protecting darkness is key to ecological integrity. When we have ecological integrity we have a healthy environment, which sustains a healthy population and a healthy economy.

Dark sky preserves

Provincial parks have great potential for dark sky protection. This is because most of the land within Ontario Parks is protected from development.

Killarney stars

In 2018, Ontario Parks protected two parks as Dark Sky Preserves: Killarney Provincial Park and Lake Superior Provincial Park. This designation from the Royal Astronomical Society of Canada means that these sites are focused on the preservation and protection of the night sky.

Provincial parks are the perfect places to experience the natural splendor of dark skies.

Learn more about the the astronomical sights of Ontario Parks here.