The Summer Solstice

You may have noticed that the days are getting longer and it's staying brighter later and later each night. This is because we are getting closer to the summer solstice, the day with the most sunlight hours all year! On June 20th, 2020 the sun will travel across its longest path in the sky this year, giving us 15.5 hours of sunlight. The sun will rise at 5:30am and it will set just after 9:00pm for us on eastern Georgian Bay.

How does this work? Why do the hours of sunlight change? Why do we have shorter days in the winter and longer days in the summer? All these answers relate to how our planet rotates around the sun.

There are two ways Earth moves that are important for all life:

1. Spin: The movement of the Earth that gives us day and night. It takes Earth 24 hours to complete one spin.
2. Rotation: The route the Earth travels around the sun. It takes one year to complete one rotation.

In addition to planet Earth's spinning and rotating, it is helpful to know it is also on a tilt. This means it has a slight angle as if it were leaning to one side. Billions of years ago a piece of space rock the size of Mars (but much hotter!) collided with Earth. The collision was so intense the Earth moved, giving it the tilt it has today.

The tilt is what causes Earth's seasons and creates summer and winter solstices, giving the planet more or less hours of sunlight. The summer solstice is the moment the northern hemisphere is at its closest point to the sun during its one year rotation. We get longer, warmer days when the northern hemisphere tilts closer to the sun in summer and we get shorter, cooler days as we tilt away from the sun in winter.

Fun Fact: The rock that hit Earth billions of years ago did more than just give us seasons. A fragment of that rock still influences life on Earth every day and you can see it almost every night. It’s the moon! The moon was a part of an ancient asteroid that slammed into Earth. The moon became stuck in Earth's gravitational obit and now controls the tides!

A riddle for you: Sarah's birthday is on December 18^th but somehow her birthday always falls in summer. How is this possible? Answer below!

The summer solstice is a time of celebration for many cultures around the world as it marks the beginning of many growing seasons. Here in the Biosphere, strawberries are among the first harvest ready to be eaten around this time of year. The summer solstice also marks National Aboriginal Day. On June 20^th 2020 let's go outside and celebrate the beginning of summer on the longest day of the year.

Activity: Create a Sundial

It is not known exactly which time period sundials came into existence but they have appeared in many ancient civilizations around the world. It's about time you try setting up your own sundial!

Here's how:

1. Using the back of a paper plate as the face of your sundial, write the 12 hours of the day around it like a clock face and decorate it to your heart's content.
2. Carefully poke a hole through the centre of the plate and place a pencil or wooden rod through the hole.
3. You might need to tape or glue the pencil so that it can stand up.
4. Bring the sundial outside and align the 12 on your clock with north*. You could also try matching up the time with a real clock to start.
5. You might need to put a small rock on the paper plate to keep it from blowing away. 
6. Let the sun do the rest of the work!How accurate is your sundial?

*Not sure how to find north? Most phones or GPS’s have compasses built into them. If you don’t have a compass, find out where the sun rises (this will be east) and sets (this will be west) and you can get a good idea of north.

Riddle answer: Sarah lives in the southern hemisphere!! When the Earth is rotating around the sun the southern hemisphere is always opposite to us up here in the northern hemisphere, so when we are in winter and have short days they are in summer and have longer days!