SUMMER (JUNE) SOLSTICE
10:57 am EDT
June 21, 2023
It is generally our custom, when posting these articles marking the first moment of a new season, to include many poetical references to that season. We have found that such lyrical citations can leaven the gloom associated with the arrival of the frigid weather periods. Of course, summer is so beguilingly beautiful it speaks well for itself. So, instead of verses, we thought we'd commemorate the solstice with what we consider to be interesting facts related to the one season that even inspires committed atheists to consider that perhaps the Universe is, at bottom, divine and benevolent.
-No, we're not closer to the Sun!
The belief that summer marks the time when Earth is closest to the Sun is arguably the most logical of all astronomical misconceptions. After all, we know that when we're huddled around the fire, be it on Christmas Eve or Memorial Day, the closer we approach the flames, the warmer our bodies become. We also know that Earth travels around an elliptical, not circular orbit, and so the planet's distance varies throughout the year. Wouldn't it be sensible to conclude that we're close to the Sun in summer and farther away in winter? Yes, though sensible, the notion is false. The distance difference of 3 million miles is slight when compared to the Sun's mean distance of 93 million miles. The variation in the Sun's angle is a far greater factor influencing our weather.
Earth is tilted on its axis 23.4 degrees relative to its orbital or ecliptic plane. Consequently, as it revolves around the Sun, the orientation of the poles change continually. On the June Solstice, the Sun reaches its highest altitude in the northern hemisphere and the lowest in the southern hemisphere. (Summer for us and winter for them.)
When at a higher angle, the Sun heats the ground more efficiently than it does in the winter and so -in theory- the temperatures are higher here in the summer than the winter. Distance has little effect. in fact, we are at aphelion, the point of greatest distance from the Sun, around July 4th. We reach perihelion, the point of least distance, around January 3!
-You can balance an egg on its end on the solstice!
It is often said that one can balance an egg on its end on the equinox. You can also balance an egg on its end on the solstice, as well. Moreover, you could balance an egg on its end on New Year's Day, Super Bowl Sunday, Valentine's Day, St. Patrick's Day, National Dress Up Your Pet Day (Yes, that's a real holiday), et cetera, et cetera. Yes, provided you possess both saintly allotments of patience and a geological period's worth of free time, you could balance an egg on its end whenever you wanted to do so. Good luck.
-The Summer Solstice is the longest day of the year. However....
At this latitude, the earliest sunrise occurs on June 15th and the latest sunset happens on June 27th. Even though the daylight length will start to decrease, we can expect slightly later sunsets for the next few days. If Earth were a perfectly spherical, uniformly dense sphere traveling along a circular orbit, the earliest sunrise and latest sunset date would occur on the solstice, itself. However, outside the Southworth Planetarium Platonic perfections are in lamentably short supply. Earth is an uneven, differentiated mess.
-As for the season on the Equator....
Well, the Equator is a circle of no thickness. So, if you were standing along the equator, the southern side of you would now be in winter and the northern side in summer. Yes, you wouldn't notice much of a difference, Also, the day length is not an issue along the equator. The daylight duration is 12 hours every single day of the year.
So, the happiest of summer solstices to you and yours!
May it be merry and bright. Well, this is New England. Let's just plan for merry.