Every atom in our bodies was created inside a star. We are all star stuff! Stars form when gargantuan clouds of hydrogen, called nebula, collapse under their own gravity. Hydrogen is the most basic and abundant element in the universe, accounting for about 75 percent of its total mass. As the nebula piles hydrogen atoms upon hydrogen atoms, pressure and temperature build until …flash! The star ignites as hydrogen atoms combine to create helium atoms in a process called fusion. Enormous amounts of energy are released as light, heat and radiation.When a star runs out of hydrogen to burn, its turns to the aforementioned helium, fusing them into carbon atoms. When the helium runs out, carbon fuses into oxygen and so on with heavier and heavier elements.
Our star, the sun, is a 4.6-billion-year-old main sequence star, consisting of 73 percent hydrogen, 25 percent helium and heavier elements making up the remaining 2 percent. Sol (Latin for sun) is a second-generation star, created from the material of first generation stars that blew up and dispersed.
To the dismay of my fifth-grade students, the sun is not massive enough to ever explode or go supernova. The sun has about 5 billion years’ worth of hydrogen left before it begins fusing helium. It will then expand, becoming a red giant. The inner planets, including Earth, will suffer extreme increases in temperature and possible consumption by the inflating sun. Hopefully, our human ancestors have found a new home by then.
Currently, the Earth is 93 million miles from the sun. Also known as 1 astronomical unit, or AU, a distance that scientists use as a scale for solar system measurements. The sun has a circumference of 2.7 million miles, about 1 million Earths would fit into its volume. The sun’s core is a fusion-inducing 24 million degrees Fahrenheit. The surface or photosphere maintains a temperature of 10,000