Spring is due to arrive this afternoon, March 20, at 12:57 p.m., though it is barely evident this year, save for the yellow crocus that came up last week beside the Camden Public Library, and the little snowdrops near a Rockport Village home. But, spring it will be, and astronomers are reassuring us that the vernal equinox is under way.

The equinox is the great equalizer, when the Northern and Southern hemispheres are equally illuminated. Now, the days will get longer and longer, until late June, when the skies stay magically bright way past the dinner hour.

Make way for those short, sweet nights of July, when the last glimpse of daylight is visible until 10 p.m. and the birds are singing at 4 a.m. — if not all night long.

“There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a ‘nearly’ equal amount of daylight and darkness at all latitudes,” according to the National Weather Service. “These events are referred to as Equinoxes.The word equinox is derived from two Latin words - aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes.  The nearly equal hours of day and night is due to refraction of sunlight or a bending of the light's rays that causes the sun to appear above the horizon when the actual position of the sun is below the horizon.  Additionally, the days become a little longer at the higher latitudes (those at a distance from the equator) because it takes the sun longer to rise and set.  Therefore, on the equinox and for several days before and after the equinox, the length of day will range from about 12 hours and six and one-half minutes at the equator, to 12 hours and 8 minutes at 30 degrees latitude, to 12 hours and 16 minutes at 60 degrees latitude.”

This technically means that we have been enjoying the progression to spring for the last few days, even while temperatures hovered above zero in the early morning hours.

Down at the University of Southern Maine’s planetarium, they are a little more poetic: “How can one not award the gold to Spring's first day?!  Astronomical winter has finally ended and spring begins!   This transition from Hell's chambers to Heaven's pastures occurs precisely at 12:57 EDT.  Astronomically, the Sun's apparent orbital path, the ecliptic, intersects the Celestial Equator.  The Sun then ascends above the Celestial Equator and will remain north of it until the autumnal equinox.”

And fear not: Though the forecast calls for another week (maybe a bit longer) of cold and snow, the first week of April looks to be splendid. We can make it! Welcome Spring.