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Imagine the Universe: Got Calcium? Lithograph

Got Calcium?

Lithograph with Classroom Activity

Got calcium?

The Milky Way galaxy doesn't contain any milk, but it sure does have a lot of calcium. There's enough calcium floating between the stars to fortify trillions upon trillions of gallons of milk.

Calcium comes from stars. In fact, all of the elements that make up your body and the planet Earth itself other than hydrogen and helium were made in stars or during star explosions.

Stars are like mighty chemical factories. They burn hydrogen and helium through a process of nuclear fusion, which produces tremendous energy. The nuclear ash, the products of fused hydrogen and helium, are carbon, nitrogen, and other atoms as heavy as iron. Eventually a star runs out of fuel to burn. At this point, the star explodes, sending all those atoms racing into space. Some atoms bump into each other in the fury, fusing to create even heavier atoms such as gold, silver and uranium. These atoms spread across the galaxy over the course of billions of years.

X-ray Image of Exploded Star, with text asking, 'Got Calcium?'


A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC

NASA Logo, National Aeronautics and Space Administration