There's more to stars than dots in the sky

A young volunteer at the Fremont Township Community Garden who is curious about stars asked, "What is the purpose of stars in the universe?"

Nature offers so many astounding sights. One of the most awe-inspiring that nearly everyone across the globe can experience is the panorama of gleaming, glittery stars against the ink-black night sky.

The greatest visibility of stars in the skies is in locations where man-made light is least present. In the U.S., the Badlands in South Dakota is known for daytime moonscape-like vistas and ink-black nights with bright, starry skies.

Here in Illinois, Apple River Canyon State Park near Galena and Illinois Beach State Park in Zion provide stargazing fans with near optimal dark conditions needed to single out stars.

The brilliant tiny dots and swirling dust visible after dark is the Milky Way galaxy - the sun, stars and gas pulled together by gravity.

Stars are continual chemical reactions involving hydrogen, about 10 percent helium, and traces of heavy elements such as iron and calcium. As gas in the galaxy collapses, heat generated creates the core of a protostar. Under the extreme temperatures reached in the stellar cores, the gasses that form stars ignite nuclear chemical reactions that form carbon, nitrogen and oxygen - the building blocks that created life on Earth.

By comparison, Earth is blanketed by an atmosphere of mostly nitrogen and oxygen. Its oceans are composed of hydrogen and oxygen, the crust includes oxygen, silicon, aluminum and heavy elements, such as iron, and the mantle and core contain iron, magnesium, nickel, cobalt and oxygen.

Astronomy expert Nadine Barlow, professor and chairwoman of the department of physics and astronomy at Northern Arizona University, explains a star's purpose: "Stars are very important to the universe, as they create all the chemical elements except for hydrogen. Without stars, there would be no carbon that makes up life-forms, there would be no oxygen for us to breathe, and there would be none of the elements that make up planets and moons."

How do stars produce the life-sustaining elements?

"These elements are created by the nuclear fusion process that powers stars - our sun is currently converting hydrogen, formed when the universe formed about 14 billion years ago, into helium. And in its later stages, it also will create carbon and oxygen," Barlow said.

"Heavier stars can create all the elements up to iron and, when they explode, they can create all the elements heavier than iron. And, of course, stars also provide the energy needed to create the temperatures and other conditions necessary for life to exist."

Next time you gaze at the heavens and reflect on the simple beauty of a complex universe, remember there is so much more to discover with the visible stars and the galaxies beyond.

The U.S. Bureau of Labor and Statistics projects stellar job growth in the area of astronomy - a hike of 14 percent over the next few decades.

Learn more about astronomy. In Lake County, Illinois, follow the Lake County Astronomical Society. Members set up telescopes at area libraries throughout the county. See http://www.lcas-astronomy.org to find out which library they'll appear at next.

Forest Preserves of Cook County also offers astronomy events. More information is available at http://fpdcc.com/events/category/activity/astronomy.

Check it out

The Fremont Public Library in Mundelein suggests these titles on stars:

• "Older Than the Stars" by Karen C. Fox

• "Stars and Constellations" by Nick Hunter

• "Space, Stars, and the Beginning of Time: What the Hubble Telescope Saw" by Elaine Scott

• "Inside Stars" by Andra Serlin Abramson

• "Universe: a Journey into Deep Space" by Mike Goldsmith