Earth Science

Orion Rising

orionBy Joanne Garton –

We all have our routines, those mental checklists we complete to make sure that our day will run smoothly. Some are entirely rational, others seem almost ridiculous, but all are part of what makes our own worlds go around. One of my self-affirming habits each winter evening is to look for Orion, to make sure that his giant frame is poised for battle in the night sky as he has been since the ancient Greeks raised his mortal body into the heavens almost 3,000 years ago.

Orion’s nighttime traverses actually began long before the Homer immortalized his character in The Iliad. The configuration of the constellation has been visible from Earth for about 1.5 million years and should stay recognizable for about 1 to 2 million more years. Ultimately, the stars will rotate within our galaxy and change their relative positions to each other, as well as to Earth. In the current wintertime sky, Orion routinely rises in the south to southeast at sunset, big and broad, early enough to entertain those of us who aren’t night owls. Betelgeuse, the supergiant that is his right shoulder, is by far the reddest object on the dark horizon and holds the allure that it may explode at any moment, collapsing under its own weight and rebounding into fiery supernova glow. The odds that this impressive event will occur tonight are “astronomically small,” but it is always worth another look.

Our solar system is anchored 28,000 light years from the middle of our own galaxy, the Milky Way, in a spiraling arm called the Orion Arm or Orion Spur. Also hosting the stars of its namesake, the Orion constellation, this arm extends approximately 100,000 light years away from the center of the galaxy, curving into a wispy piece of the giant pinwheel that we inhabit. Dinosaurs were just beginning to roam the Earth when our galactic arm was last in the particular position approximately 230 million years ago. Orion, in myth or science, had not actually been born.

Despite his regular presence in my contemporary winter routine, I am continually amazed come summer when Orion’s enormous frame actually vanishes from my nighttime glances. From about mid-May to mid-July, Orion is not visible in the night sky because he is hunting the heavens entirely while the sun is shining. The summer sky also holds its own treasures, but it does seem as if the crisp winter air makes the stars brighter and my frigid stargazing with Orion more admirable.

Actually, winter stars are brighter, or rather less clouded, than their summer counterparts. During the winter, the nighttime view from the northern hemisphere is directed away from the center of our galaxy and towards the outskirts of the Orion Arm and nearby Perseus and Sagittarius Arms. Looking all the way into deep space, our view is less obscured by the galactic dust of the central bulge and only a diffuse band of our own arm in the Milky Way graces the skyline. During our summer, when our night view points towards the galaxy center, the gases of the greater Milky Way dull the glow of stars and planets and the Orion Arm appears as a broader and brighter fuzzy band of stars sweeping across the sky.

The cold air of February may drive us into the depths of cabin fever but while we huddle by the heaters, the Earth will continue its tiny rotation in the giant universe, the pieces of its night sky moving together in a predictably off-kilter dance between the nearby moon and the backdrop of outer space. This month, Sunday, February 10th marked the new moon and the darkest skies. With the guarantees that only a galaxy can offer, Orion will be there this month rising in the south, Polaris in the north. As an extra treat, a bright Jupiter will be visible to the left and below the moon. So pull on that sweater and extra pair of pants and spend a moment with Orion and some of his closest winter friends. It will always be reassuring to know that, for the imaginable future, they will follow a dependable yet spectacular winter routine.

Joanne Garton is a master’s candidate in the Ecological Planning program who loves rocks, building things, swimming, and Scottish strathspeys sets. When not working in the field, she can be found in her home town of Montpelier.


1 thought on “Orion Rising”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s