It’s all about the sun. Always has been, always will be. Our lives depend upon the unstoppable nuclear fire that burns in its heart. At no time of year do we feel closer to that fire than at the summer solstice, when the sun reaches its highest point in the sky in the northern hemisphere.
At 5:51 a.m. tomorrow morning June 21 – just after sunrise for my little town – summer begins. If you’ve been paying attention, you’ve noticed the sun creeping higher and higher since the time you last shoveled snow. Well, the buck stops at summer. That’s when the sun stands 23.5 degrees above the imaginary circle in the sky called the celestial equator, an extension of Earth’s equator onto the sky.
For anyone living along the equator, its celestial counterpart starts at the eastern horizon, passes directly overhead and then arcs down to the western horizon. In mid-northern latitudes, the celestial equator crosses the southern sky about halfway between the horizon and zenith. Add in 23.5 degrees or about two fists held at arm’s length against the sky, and that’s where the solstice sun stands around 1 p.m. daylight saving time.
23.5 is a familiar number. You’ll recall that’s the tilt of Earth’s axis. No coincidence there. The sun’s yearly swings from its summer peak at 23.5 degrees above the equator to 23.5 degrees below the equator at the winter solstice is merely a reflection of that tilt. In reality, the sun’s not moving at all – it’s the Earth’s doing.
On the summer solstice, Earth’s north polar axis tilts toward the sun, ‘lifting’ it 23.5 degrees above and beyond the equator. Not only is the sun high in the sky, it’s up for many more hours than during the winter. Days reach their maximum length and the sun’s high angle means the energy per unit area it pours over Earth’s surface is more than twice as intense as during the winter. Add it all up and you’ll start feeling … sweaty.
Enjoy the best the sun can bring to the game these next three months. Happy solstice!