Monday was a pretty nice first day of spring. I had to go in to work a bit later than usual and as a result I was treated to sunshine on my morning ride down the Hank Aaron State Trail. The sunshine and warmth allowed me to pedal in wearing only a sweater and cap. As hip as I look in the photo to the left, you may find it hard to believe that I was sort of a geek in high school. In fact I was president of the Muskego High School Astronomical Society. That is actually how I got into photography, through deep-sky astrophotography. I have forgotten most of the astrophysics I knew then, but events like March equinox dislodge some of those old bits of information from the darkest corners of my 49-year-old brain.
March Equinox actually occurred Sunday at 6:21 pm, but Monday was the first full day of spring. March Equinox marks when the sun crosses the celestial equator from south to north. It is also when night and day are about the same length with the days getting longer and nights shorter. In the northern hemisphere March Equinox is also called Vernal Equinox because it kicks off spring. In the southern hemisphere it is called Autumnal Equinox for the start of fall.
All this happens because the earth is tilted on its axis by about 23 degrees, so as the earth orbits the sun, the sun appears to moves up and down across the sky as the seasons change. While I couldn’t integrate my way out of a paper bag anymore, I enjoy it when one of these tidbits of knowledge comes to mind.
The weather forecast looks like my memory of that spring ride will have to carry me through the rest of the week. Did you manage to take a memorable vernal ride?