Mon June 19, 2023 ANCIENT SUN TEMPLES
Stonehenge, built over forty centuries ago, is one of over a thousand circles of standing stones that can be found throughout the British Isles and Europe. On the first day of summer, the sun can be viewed perched above an outlying heelstone, as viewed through a central arch of stones. In ancient Egypt, temples were built so that at the summer solstice, the sun’s rays shone through tall columns to sanctuaries within. At the Bighorn medicine wheel in Wyoming, piles of carefully placed stones point toward the summer sunrise. For hundreds of years in New Mexico, a slender ray of sunlight – the sun dagger of the Anasazi – sliced through a petroglyph spiral on the first day of summer. And there is the Sun Temple, built by the Incas at Machu Pichu – but of course Peru is south of the equator, and now it is the winter solstice sun that is framed in this ancient observatory’s window.
Tue June 20, 2023 SUMMER SOLSTICE
Summer begins tomorrow morning, June 21st, shortly before 11 am. It is at that precise moment that the sun will shine directly overhead at local noon, not here in Florida obviously, but as seen from a point on the Tropic of Cancer at twenty-three and a half degrees North latitude. When it’s local noon here, the sun will be as high in the sky as possible for our latitude. Along this part of the Treasure Coast, we’re at 27½ degrees North latitude, so at midday today the sun will be about 4 degrees south of our zenith. This is the summer solstice, as the sun stops its northerly progression, due to the inclined tilt of the earth’s axis as it revolves about the sun; sol/stice – sun stop. It also marks the longest period of daylight and the shortest period of night in the year, at least in Earth’s northern hemisphere.
Wed June 21, 2023 NAME THAT CONSTELLATION - JUNE
Can you identify the thirty-first largest constellation? It is bordered on the north by the constellation Lynx the Bobcat, and on the south by Hydra, on the west by the Gemini, and on the east by Leo the Lion. There are no bright stars here, and it is one of the darkest regions in the night sky. But there is a beautiful open star cluster within its borders, known as the Praesepe or Beehive cluster, and some of its stars have been found to have planets orbiting them. In mythology it was a crustacean that was sent by the goddess Hera to attack the hero Hercules. It was accidentally crushed by Hercules during the fight, but Hera restored it to life in the heavens as a constellation. Tonight the waxing crescent moon and the planets Venus and Mars appear close together within its borders. Can you name this star figure, the third constellation of the Zodiac? The answer is Cancer the Crab, high in the south after sunset.
Thu June 22, 2023 PLUTO AND ITS MOONS
On June 21st, 1978, Pluto's moon Charon was discovered by the American astronomer James Christy. In mythology, Pluto was god of the underworld. Charon was his ferryman, who transported souls across the river Styx to the other side. Styx is another, more recently discovered moon, along with three more – Hydra, Nix and Kerberos. Charon is the biggest one, it’s about half the size of Pluto. So when it orbits this distant world, Charon's mass has a substantial effect on Pluto, pulling it first one way, and then the other. In the year 2015, a space probe flew past Pluto and Charon, and sent back incredible pictures and information – ice mountains two miles high, vast nitrogen ice plains, and mysterious dark patches on Pluto’s farside. If you visit the website NASA dot gov, and enter the word “Pluto” in the search box, you can see these pictures for yourself.
Fri June 23, 2023 CONSTELLATIONS VS. ASTERISMS
In 1930 astronomers recognized 88 official constellations. There are (and were) a great deal more unofficial star patterns, called asterisms. In order to be a constellation, everybody has to agree that that’s what it is. An asterism is more personal, and usually a lot easier to see or imagine. So the Great Bear, Ursa Major, includes the stars of the Big Dipper (what we call it here in America,) or the Plough (England,) or the Chariot (ancient Rome.) The front end of the constellation Leo the Lion is called the Sickle, as it looks like the tool that was used to harvest the crops. Cygnus the Swan becomes the Northern Cross, Scorpius becomes the Fish Hook, and Sagittarius the Archer looks like the crude outline of the Teapot. When you first start to trace out the constellations, these asterisms will help make the more complex patterns easier to learn.