The concept of solstices and equinoxes can sometimes be a little confusing but this blog and our Stories in the Sky show series helps break it down for you.

Every year in June between the 20th-22nd, Earth experiences one of the solstices.  Here at Stardome we are celebrating the winter solstice on the same day as the northern hemisphere is celebrating their summer solstice: Friday 21st June; with a special screening of Winter Stories in the Sky at 6pm!  This show takes place on the night of our winter solstice, delving into the reasons for our seasons as well as how we can all be astronomers using constellations from Greek myths and Māori pakiwaitara.

Our modern calendar is based off ancient solar calendars, so many of our festivities are linked to astronomic events.  However, around the world it is the winter solstice that is often marked as the time for the biggest celebrations.  This is the time when agricultural societies marked the return of the Sun after passing though the coldest and darkest time of the year.  Celebrations around the winter solstice encompass festivals such as Matariki for Māori in June. In the northern hemisphere, they celebrate the winter solstice in December with Dong Zhi for Chinese, Saturnalia for Romans, Yalda for Persians, and Soyal for Hopi – just to name a few.  This makes astronomy an important part of many ancient societies’ everyday lives to mark seasonal change.

The combination of the tilt of Earth’s axis and its path around the Sun is how we get different seasons through the year.  The tilt of Earth doesn’t change through the year, but as we move from one side of the Sun to the other, the part of Earth tilted towards the Sun changes from one side of Earth to the other.  The hemisphere tilted towards the Sun experiences more direct rays of sunlight and therefore gains more heat and light (summer).  Not only does the temperature change depending on how the rays of sunlight spread out on the surface of our planet, but the number of hours each latitude spends in the daytime half also changes.  The hemisphere tilted away from the Sun experiences a longer period of night in the shadowed half of the planet, and thus has shorter hours of daylight (winter).  The two extremes of this phenomenon are the solstices.  The midpoint between the solstices are the spring and autumnal equinoxes where the length of day and night are equal. 

To see how this all plays out from the surface of Earth to a journey into space, book your special screening tickets here

For further reading to learn more, check out Time and Date and Britannica. 

Author: Vanessa Rancour, Education Manager