In the northern hemisphere, the winter solstice has arrived – marking the first day of winter in the astronomical calendar. For those in the southern hemisphere, it is the first day of summer.
In school, you’re taught the make-up of the seasons, with December-February often considered winter, March-May spring, June-August summer and September-November autumn.
This is the meteorological breakdown, largely based around the annual temperature cycle.
However, there is a way to measure the seasons that’s slightly more scientific, using astronomy. In this sense, the rotation of Earth around the sun is marked with four key natural phenomena: the spring equinox, the summer solstice, the autumnal equinox and the winter solstice.
The solstices mark the times when the sun’s annual path is farthest, north or south, from the Earth’s equator. So today (21 December) the winter solstice is here, marking the day in 2016 with the fewest hours of sunlight.
Traditionally, countries throughout the northern hemisphere host celebrations to mark the event, often dating back to pagan times and in Ireland, Newgrange is the key landmark in this regard.
The solstice is named for the brief time when the sun appears to pause its movement across the sky. At that moment, the tilt and rotation of the earth shifts our view of the sun’s direction from southward to northward, causing it to hang momentarily suspended.
Doodler Nate Swinehart created a family of anthropomorphised rocks to commemorate the winter equinox.
Meanwhile, in the southern hemisphere, the opposite is true. So Google doubled up, with Swinehart’s Doodle showing the same family of rocks enjoying a warmer spell to commemorate the change of season.