Category: earth

There are many places on Earth that most of us will never have the opportunity to visit. Like Antarctica. Of course, there is no limit to the places on Earth and beyond that we can visit with our imagination. With no suitcases to pack, plane tickets to purchase or hotel rooms to book, an Imagination Vacation might not be so bad after all!

Antarctica is a little chilly, so let’s go somewhere a bit warmer. Let’s take a look at an island that most of us will never visit for ourselves: Canada’s Sable Island.

A satellite photo of Nova Scotia.

A satellite photo of Nova Scotia.

Sable Island is a tiny little sand bar located about 160 km southeast of Nova Scotia, on Canada’s East Coast. A sand bar is a landmass made up of sand; the word “sable”, in fact, is French for “sand”. Sable Island is 42 km long, and about 1 1/2 km at its widest point. From an airplane, it looks a little bit like a thumbnail!

A sattelite photo of Sable Island.

A satellite photo of Sable Island.

An even closer view.

An even closer view.

Once we get a little bit closer, we see that Sable Island is covered in beaches, sand dunes, grasses, and other low-lying plants. It is definitely warmer here than the Antarctic! Temperatures reach a pleasant 25°C at the peak of summer, and it only goes down to about -5°C in the winter. It’s windy, too! Sable Island’s shape is constantly changing due to strong winds and ocean storms.

Only five or so researchers live on the island year-round. Photographers and scientists sometimes come to visit in the summer months. It may be a bit of a lonely spot for humans, but not for the wildlife living here! Aside from hundreds of invertebrae and insects, over 330 species of birds have been spotted over Sable Island, with several species choosing to nest here. Five species of duck nest on the island as well. It is also home to Harbour and Grey Seals, and is frequently visited by large numbers of other species of seals.

Maybe you’re starting to wonder why we would ever want to visit this sandy little thumbnail, even on an Imagination Vacation. There are lots of other places we can go to see sand and birds and ducks and seals. Well, it just so happens that Sable Island is famous for some very special inhabitants: We’ve come here to see the island’s wild horses, peacefully grazing along the sand dunes and beaches.

A group of Sable Island horses graze near a pond.

A group of Sable Island horses graze near a pond.

Courtesy: Sable Island  Green Horse Society

Courtesy: Sable Island Green Horse Society

Sable Island is home to about 300 beautiful wild horses. They are among the very few wild horse populations that humans do not interfere with in any way. But where did the Sable Island horses come from in the first place?

A popular myth is that these horses are descended from shipwreck survivors. There have been about 350 recorded shipwrecks on Sable Island over the past few hundred years due to violent ocean storms and fog. Sable Island is sometimes called “The Graveyard of the Atlantic” for this reason. But the horses did not arrive this way.

Most evidence that we have today tells us that these horses are actually descendants of animals taken from the Acadians during the Great Expulsion in the mid-1700s and brought to Sable Island by a Boston merchant. He attempted to establish a farming settlement but was unsuccessful. The horses were left behind and continued to breed and thrive. Because the present-day horses are descendants of domesticated animals, it is much more accurate to say they are “feral” horses rather than “wild”.

Sable Horses

In the past, some of these horses would be rounded up and shipped off the island to be sold or used in Cape Breton coal mines. In 1962, the Canadian government gave full protection to the horse population from human interference. Now they are free to gallop the dunes and roam the seashore. What a wonderful place!

Look up. Look waaaaay up!

Since we’re hanging out at the South Pole, let’s take a minute and do some sight-seeing. Maybe you’re wondering what sights there could possibly be on a continent almost entirely covered with ice. Don’t worry. What we’re interested in isn’t found on the ground. It’s high up above our heads, in the night sky: The Aurora Australis, also known as the Southern Polar Lights.

Aurora Australe

Photo © Samuel Blanc

Aurora Australis dancing in the night sky.

Aurora Australis dancing in the night sky.

Beautiful!! These brilliant lights get their name from Aurora, the Roman goddess of dawn. “Australis” is a Latin word, and means “of the South”. The Aurora Australis are only visible at night in the farthest Southern regions of the Earth, in Antarctica, South America, and Australia. But these are not the only places we can go to see auroras.

There are Northern Polar Lights, too. They are brightest near the North Pole, but are sometimes visible from many locations in the Northern Hemisphere all over the world. Another name for the Northern Lights is Aurora Borealis. “Borealis” comes from the Greek name for wind. Both Southern and Northern Lights look like colourful curtains draped over the night sky, swaying in the wind.

Aurora Borealis near the North Pole.

Aurora Borealis near the North Pole.

Pretty colours light up the sky above Alaska.

Pretty colours light up the sky above Alaska.

Most people have heard of the Northern and Southern Lights before, and many people have even seen them for themselves. But have you ever thought about what these lights are, and why they are brightest at the North and South Poles?

There are a few different things at work. First, there is an invisible magnetic field (called the magnetosphere) that surrounds the Earth. We do not really understand the origins of this magnetic field, but it probably has something to do with the Earth’s rotation, and the materials that make up its core. An easy way to think about the magnetosphere is to imagine a giant bar magnet running through Earth, at a slight angle. One end is near our North Pole, and the other end is near the South Pole.

A visual representation of the Earth's magnetic field.

A visual representation of the Earth's magnetic field.

Earth’s magnetosphere is always changing and moving. This means that the North Magnetic Pole is not the same as the North Pole on the map (called Geographic North Pole). Same goes for the South Pole. As you can see in the illustration above, the imaginary magnetic lines are closest together near the Earth’s Geographic North and South Poles, which means that these areas are where the magnetic field is strongest. This is why auroras only show up near the poles. But we need more than an invisible magnetic field to make Aurora Australis and Borealis.

Next, we need some Solar Wind. Electrically charged tiny little particles that make up the Sun’s atmosphere are constantly boiling off and flowing into space at extremely high speeds. This creates Solar Wind. It is what blows a comet’s tail away from the comet as it flies through space.

Comet Hale-Bopp's tail flows back from its head due to Solar Winds.

Comet Hale-Bopp's tail flows away from the head due to Solar Winds.

Solar Wind is also what powers our beautiful Northern and Southern Lights. It pushes on the Earth’s magnetosphere and changes its shape. The Solar Wind squishes the magnetic field on the side of Earth facing the sun as it flows over us, and stretches it into a long tail called a magnetotail behind us.

A visual representation of Solar Wind and its effect on the Earth's magnetosphere.

A visual representation of Solar Wind and its effect on the Earth's magnetosphere, shown in blue.

Some of the charged particles from the Solar Wind are also being pulled towards the Earth by the magnetosphere itself. When conditions are just right, the magnetotail funnels them towards the magnetic poles. Once in the upper layer of our atmosphere, these particles crash into gas atoms  (tiny little invisible particles that make up the air you breathe), which creates energy. So far, this entire process has been invisible. Now things become exciting. The energy is released as light! The colour of the light depend on what kind of gas atoms the particles crash into, which varies depending on how high up in the atmosphere this crash occurs.

Beautiful Northern Lights.

The Northern Lights.

Now you know! Isn’t science beautiful?