By Kyle Jeter
New and old intertwine as my 5.0-milliwatt, 532-nanometer green laser traces patterns of stars that, in many cases, were first outlined by our ancient ancestors’ thousands of years ago.
Some of these patterns are full-fledged constellations, while others are smaller pictures found within the 88 official constellations – so-called asterisms.
The famous Big and Little Dippers, for example, are not actually constellations in and of themselves but are easily identifiable asterisms within the constellations Ursa Major and Ursa Minor, respectively. Other well-known asterisms include the Summer Triangle, the Teapot of Sagittarius, the Keystone of Hercules, and the Great Square of Pegasus.
As the bright green ray of laser light slices through the still night air, I can almost see the light bulbs turning on in my students’ minds as they begin to connect our classroom learning to the actual night sky.
At such a moment, I can imagine the elders of ancient tribes sitting around a fire at night and sharing stories of the sky handed down to them through countless generations.
Now, however, anyone of any age can easily identify the constellations on their own using technology that was almost unthinkable when I began teaching in 1994. Apps such as StarWalk or Google Sky allow you to point your cell phone toward any section of the night sky and visualize the outline of the constellations in vivid detail.
Even though this technology has been around for a few years now, I’m still amazed by it!
Learning how various cultures around the world interpreted the same areas of the sky has always fascinated me. Where the ancient Greeks saw a Scorpion’s tail, the ancient Polynesians visualized a giant fishhook (Disney’s Moana illustrates this wonderfully).
Whereas most cultures made patterns of the stars, the Incas and Australian Aboriginals notably also recognized patterns in the dark clouds of the Milky Way itself. They saw animals such as a Llama (Incan) or an Emu (Aboriginal).
And the wildly creative mythologies around the world that sprang from these various sky interpretations are remarkable both in their similarities and differences. For example, why did so many disparate ancient cultures view the Pleiades Cluster of stars as the “7 Sisters”? Could some common mythologies date back to our common African heritage? We don’t know.
Although the ancient mythologies written in the stars are entertaining, another type of star story is revealed to astronomers by the real-world celestial objects found within the constellations. That is the story of how stars are created, evolve, and ultimately burn out.
For instance, within the Orion constellation, a cloudy spot below his famous Belt (another asterism) represents part of his dagger. However, what appears as a tiny smudge to the human eye is actually a vast star-forming cloud known as the Orion Nebula. It is about 24 light-years in diameter (for scale, it takes light only about 5 hours to travel from the Sun to Pluto!).
Despite being approximately 1,300 light-years from Earth, the nebula can easily be seen with the naked eye.
Peering inward with the Hubble Telescope, astronomers have spotted tiny disks surrounding some newborn stars forming within the Orion Nebula. These “proplyds” (short for protoplanetary disks) contain the building materials for future Solar Systems.
Let gravity do its thing for a few million years and – voila! You have yourself a system of planets in orbit around a fledgling star.
Once a star ignites, its lifespan is dependent upon its mass. The most massive stars shine magnificently but are doomed to destruction. Stars such as Deneb in Cygnus and Rigel and Betelgeuse in Orion fall in that category.
The star Bellatrix (one of many names borrowed from the sky by author J.K. Rowling for her Harry Potter novels) may also meet the same fate, but its mass is borderline.
At the other end of the stellar spectrum, dull, reddish, low-mass stars may burn for trillions of years. Our Sun’s nearest neighbor star, Proxima Centauri, is such a star. They don’t garner much attention, but they are the most numerous types of stars in the Universe.
Stars are typically born in clusters, such as the magnificent Pleiades in Taurus or the Beehive Cluster in Cancer the Crab.
The young stars of these so-called Open Clusters will drift apart after a relatively short time, but for now, they often make perfect viewing targets for a pair of binoculars or a small backyard scope.
The vast majority of stars, including our Sun, will never explode as a supernova. Instead, they will undergo a remarkable transformation toward the end of their energy-producing run in which the star’s outer shell separates from its core. As the outer material drifts away, the inner shell acts like a lightbulb illuminating the outer shell like a lampshade.
These short-lived planetary nebulas are some of the most colorful, striking, and intricate objects in the heavens. The Ring Nebula in Lyra and the Dumbbell Nebula in Vulpecula are planetary nebulas worth searching for (although a telescope will be needed).
As for the ultra-massive stars that do experience a fiery, explosive end, the shell of these supernova explosions form yet another type of nebula called a supernova remnant, or SNR. These are rare objects in part because they dissipate rapidly. The Crab Nebula in Taurus is a prime example.
Collectively, these nebulas and star clusters allow astronomers to understand the life cycle of stars. For generations, astronomers have painstakingly pieced together this complex tale of stellar evolution. And although there are always gaps in our knowledge, astronomers now understand the physics of stars to a remarkable degree and can predict their fate to a high degree of accuracy.
Whether you are learning to identify the constellations with only your eyes and an app as a guide, or you are beginning to scan the skies for nebulas and star clusters with a telescope or binoculars, countless treasures await your discovery.
Take some time to learn the night sky as our ancestors once did. Each of these celestial gems has a story to tell.
Kyle Jeter has been reading about Astronomy since he was five years old and has never stopped learning since. Since 1994, he has both lived in Coral Springs and worked at Marjory Stoneman Douglas. He has a daughter, Kayla, and a son named Kyle. Jeter started the Astronomy program at the high school in 1997.
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