The June solstice 2022, which is recognized as the official start of the summer in the Northern Hemisphere, will occur on Tuesday, June 21, at precisely 5:14 a.m. EDT (09:14 GMT).
But for other parts of the world, the solstice is looked upon not as the start of summer, but rather as midsummer. If, for example, you were to pay a visit to Sweden or Norway at this time of year, you would find the local inhabitants celebrating a local holiday known as Midsummer's Day, which by ancient custom falls on June 24, a day also linked with the name of St. John the Baptist. At night, fires are lit in the mountains in other parts of Europe.
In northern Scandinavia, above the Arctic Circle, the phenomenon of the midnight sun at solstice time is a seasonal clock which seems to divide summer, if not the entire year into two distinct parts. It is that time of the year that the sun, having spent the previous six months plodding steadily northward has reached the pinnacle of its migration. The word solstice is derived from the Latin: solstitium; the conquering sun briefly halts in its northward motion, having realized full victory over the forces of darkness.
Immediately thereafter it begins its journey south.
So, the solstice really does not mark the beginning of a season, rather to all appearances has actually reached its peak height.
As an example, north of latitude 55 degrees, since the start of May, a twilight glow has persisted through the night; dim at first, but now around the solstice it appears quite bright. And it will persist all the way through July before finally fading out completely in early August; such subarctic twilights virtually put a temporary end to nighttime conditions. And even places well outside of the Arctic Circle, the sun goes below the horizon for only 8 or 9 hours. From New York, Omaha and Salt Lake City, taking twilight into account, there are only about five hours of total darkness.
Journey to the bottom of the Earth
Last December, I was invited to participate in a cruise to Antarctica, staged by the French cruise ship operator, Compagnie du Ponant (opens in new tab). I was to serve as an onboard astronomy guide, preparing passengers for a total solar eclipse that would sweep across the frozen continent on December 4. We were to encounter the moon's shadow as it passed over ice floes in the Weddell Sea.
Unfortunately, clouds obscured our view of the totally eclipsed sun, but during my two-week stay on board Ponant's exploration ship, Le Commandant Charcot, I observed things that people who have lived all of their lives at mid-northern latitudes would never see.
First, since we journeyed so far south (to just outside of the Antarctic Circle) and it was only a few weeks before the December solstice, we experienced a considerable amount of daylight. In fact, it was a bit of a jarring experience having the sun setting below the north-northwest horizon as late as 11:15 p.m.
And it didn't stay out of sight very long, popping back up above the north-northeast horizon just a few hours later at 2:30 a.m. While we did not experience the "midnight sun" effect, the twilight remained very bright and always precluded us from sighting any stars.
This month, with the occurrence of the solstice on June 21, those living in places like Fairbanks, Alaska, Reykjavik, Iceland and Tornio in Finland will be experiencing pretty much the same effect.
Also interesting was the fact that that the sun appeared to track across the sky from right-to-left, peaking at midday in the north, quite unlike what us northerners are accustomed to seeing the sun normally do: move across our line of sight from left to right, peaking at midday in the south. The astronomical term "right ascension" likely was derived from this effect, though for those living in places like Santiago, Chile, Johannesburg, South Africa and Sydney, Australia, celestial objects always ascend toward the left!
Penguins on Earth, but not in the sky
Of course, a journey to Antarctica means encountering penguins. One of our stops was to Paulet Island, a circular volcanic slab about a mile in diameter, off the north-eastern end of the Antarctic Peninsula. The island supports a very large breeding colony of about 100,000 pairs of Adélie penguins.
While the Ponant naturalists told us not to approach any closer than 15 feet to the penguins, somebody forgot to tell the penguins that. Some would waddle up to us no differently than pigeons do in New York's Central Park.
It also got me to thinking why, of all the birds portrayed in the night sky as constellations, there is not a single penguin represented, even in the far-southern skies; there's a toucan, a peacock and even a bird of paradise, but no penguin.
It must be remembered, however, that the first penguins were not discovered by European explorers until the late 15th century and probably were still considered a very exotic and virtually unknown creature to many celestial cartographers who created the classical star atlases of the 17th and 18th century, with their allegorical portrayals of persons, animals and inanimate objects.
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications. Follow us on Twitter @Spacedotcom and on Facebook.