We’re all stellar, literally.

The iron in your blood, the calcium in your bones, and the gold and silver you may be wearing were all forged out of an unknown star that exploded eons ago.

In fact, all heavy elements in our world, or any other, were exclusively cooked up in the colossal explosion of huge stars. These explosions are also known as supernovas. Astronomers and scientists agree that this is the only way that these elements could physically come into existence.

Every star in our sky, including our sun, is basically a huge ball of hydrogen gas held together by gravity. Since they are so massive, the star’s gargantuan gravitational force compresses the ball of gas so hard that a huge amount of heat builds up in the core of star, to the tune of millions and millions of degrees.

That drives the hydrogen atoms at each other so hard that they fuse together into heavier helium atoms. The details are really hairy, but when that happens it produces tremendous amounts of light and other radiation. This is the process of nuclear fusion.

As stars age, hydrogen atoms become depleted and helium atoms begin to pile up. When the hydrogen has totally run out, the helium core begins to get squished due to gravity.

This compression dramatically drives up the core temperature even more, and the expelled heat fires up nuclear fusion in the outer layers of the star. This causes the entire star to bloat out into what’s known as a red giant.

This is going to happen to our own sun about 5 billion years from now. When it does, bad things will happen. The sun will swallow up the planets Mercury and Venus.

The edge of the sun won’t be all that far away from Earth. Needless to say our world will get fried and never be the same.

After another billion years or so, when the sun completely runs out of nuclear fuel, gravity will totally take over and our home star will collapse under its own weight and get compressed into a white dwarf star.

The sun will be down to about 8,000 miles in diameter by then, about the size of Earth. Eventually the new white dwarf will flicker out, and Earth and the remaining planets will orbit a totally dead star.

Much larger stars, at least eight times the mass of our sun, will meet a much more violent end. As they run out of hydrogen in their cores they become super huge red giant stars.

An example of a super red giant star is Betelgeuse, the second brightest star in the winter constellation Orion the Hunter. It marks the armpit of the great celestial hunter. Betelgeuse is at least 400 million miles in diameter, but occasionally expands out to about a billion miles in girth. It’s probably the biggest single thing you’ve ever seen.

No one knows for sure when it will happen, but sometime within the next million years Betelgeuse will explode in unimaginable proportions. It will go supernova.

There’s no way I can get into all of the details, but essentially what happens is that stars like Betelgeuse develop iron cores due to excessive levels of nuclear fusion. Hydrogen fuses into helium that fuses to heaver carbon and oxygen atoms, and that trend of fusion continues until iron is produced.

At that point giant stars like Betelgeuse become unstable and the star literally blows itself to bits. During this annihilation, matter is strewn violently in all directions at speeds over 10 thousand miles a second.

At the same time heavier elements like gold, silver, uranium, and many others are “cooked up” in all of the heat and chaos in what’s called nuclear synthesis.

So how did all of these elements make it to Earth and eventually into our bodies?

Astronomers believe the giant hydrogen gas cloud that gravitationally collapsed into our sun and solar system was laced with heavy elements from a supernova, or very possibly multiple supernovas.

It’s been a long time since we’ve had a major supernova explosion in our neighborhood of the Milky Way galaxy. The last one recorded was way back in 1054 A.D. We know that because it was documented by Chinese astronomers.

It was said to be so bright that it was visible during the day for almost a month. Nearly 1,000 years later, the remnants of this supernova explosion are still visible but considerably fainter.

It’s called the Crab Nebula, located in the horns of the winter constellation Taurus the Bull. With a moderate telescope it will show up as a faint patch of light that way back in the day was a mighty star over 37 thousand trillion miles away.

You and everyone you know is made of star stuff, so make your life shine.

Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/Paul and is author of the book, “Stars, a Month by Month Tour of the Constellations” published by Adventure Publications available at bookstores at http://www.adventurepublications.net