Scorpius and Libra dominate the southern sky in early summer. This map show the two constellations and their featured stars around 10:30 p.m. as you face south. Created with Stellarium
Each one of us makes our own associations with the stars. Some connect the appearance of a constellation in the evening sky with a particular month or season. Seeing it conjures up visions, smells and deeper associations. Others find that certain stars or constellations recall a time in their youth, a relationship or even a great vacation.
Something stirs in me every June when the great scorpion with its flickering red “heart” rises up in the southeast. I’m reminded of nights when my children and I would sneak up on fireflies in the yard and snatch them from mid-air with our hands. We’d put them in a jar to admire their flashes and then set them free later that night.
Scorpius tells me summer is here, the daisies are up and the tomatoes are climbing. Today June 20 marks the start of summer set to begin officially at 6:09 p.m. (CDT). Early sunrises and late sunsets conspire to make this the longest day of the year. Yet as my wife reminds me: “It’s all downhill from here.”
The difference in altitude of the sun at summer solstice (left) and winter is dramatic. The extra height means longer days and more direct sunlight resulting in a surge of heat over the summer months.
She’s right of course when it comes to day length and sun altitude. The sun stands at the top of the mountain today – as high in the sky as it can possibly get for the northern hemisphere.
Starting tomorrow, it starts rollin’ back down the hill, headed for the winter solstice in December, when it will stand barely two fists high at noon from my front yard.
Remember that this is reversed in the southern hemisphere, where today’s the first day of winter.
Earth’s northern hemisphere faces toward the sun in the summertime giving us a high sun and long days. In the winter, we face away from the sun. Diagram not to scale. Credit: Tau o’lunga
We live with the sun. Even if we haven’t watched its steady upward since last December, we know it’s getting hot out there. The long days and steep gaze of the sun warm up half the planet, unleashing a million living things. The celestial scorpion is another of winter’s prisoners set free by summer’s easy ways to roam the southern sky.
To make its acquaintance, just head out after nightfall around 10:30 p.m. The Big Dipper will be high up in the northwestern sky, but if you face exactly the opposite direction (southeast) and look 2-3 outstretched fists up from the horizon, you’ll be met by the red twinkle of the scorpion’s heart, Antares (an-TARE-eez).
The sun is almost insignificant next to the red supergiant star Antares.
Antares is bright not because it’s particularly close – 550 light years – but because it’s just so huge. If put in place of the sun in our solar system its sizzling surface would balloon out beyond Mars almost to Jupiter. Trickling down from Antares toward the horizon is the back end of the venomous scorpion; poking forward in a rather aggressive manner are the stars that form his head.
The three-in-a-row pattern at the front of the head is reminiscent of Orion’s three-in-a-row belt stars. This is oddly appropriate given that the scorpion and the hunter are mortal enemies in Greek mythology, the apparent reason the constellations were placed in opposite ends of the heavens. When Orion sets, Scorpius rises.
Scorpius represents the scorpion who stung Orion to death. Libra was once part of Scorpius but was later formed into a separate constellation.
Ahead or west of the the scorpion is a group of fainter stars in the shape of a diamond. These used to represent the claws of the arachnid but were parted away in Roman times to form Libra the Scales.
Vestiges of the scorpion remain in the names of Libra’s two brightest stars – Zubenelgenubi (zoo-BEN-el-je-NEW-bee), or “southern claw” in Arabic, and Zubeneschamali ( zoo-BEN-ess-sha-MAH-lee) or “northern claw.” Say the names out loud to enjoy the sound of their syncopated sonorities. We’ll visit Scorpius and Libra again soon for a look at some of their binocular and telescopic treasures.
Article by astrobob www.astrobob.areavoices.com
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