The Longest Day

June 21^st is the year's longest day. But do you know what it actually means? The longest day is also called the Summer Solstice and occurs when the sun is at its greatest distance from the equator.

As the Earth travels around the Sun in its orbit, the north to south position of the sun changes over the course of the year, due to the changing orientation of the Earth's tilted rotation axes. The date of the maximum tilt of the Earth's equator corresponds to the Summer Solstice and also to the Winter Solstice.

The word ‘solstice’ is derived from two Latin words: "sol" meaning sun, and "sistere" to cause to stand still. So solstice means when the "sun stands still" and comes from the shadow on the sun dial changing minimally on and near the Summer Solstice.

This longest day marks the first day of summer and should in theory mean warmer weather as the North Pole leans more directly toward the sun than it does on any other day of the year.
After the summer solstice the sun follows a lower path through the sky with each day becoming shorter and shorter.

Interested in learning more about the solar system? Have a look at our Outer Space Fact Finder and Glow in the Dark Solar System