…Really COOL Stuff… from Stars

In the Star Trek: The Next Generation episode called “Home Soil,” the crew of the starship Enterprise run into a life form that, when they finally figure out a way to communicate with it, calls the humans “ugly bags of mostly water.” It’s a great line, but it’s also true: we ARE mostly water.

In fact, if you break down the elements in our bodies by how much there is of each one, you get this list:

• 65% oxygen
• 18% carbon
• 10% hydrogen
• 3% nitrogen
• 1.5% calcium
• 1.0% phosphorus
• 0.35% potassium
• 0.25% sulfur
• 0.15% sodium
• 0.05% magnesium
• A mix of copper, selenium, fluorine, chlorine, molybdenum, iodine, cobalt, manganese, and iron that comes to about 0.70%
• Another mix of lithium, strontium, aluminum, silicon, lead, vanadium, arsenic, bromine that are in very small trace amounts

So, we ARE mostly water, when you combine the oxygen and hydrogen to make H₂0. Our skin, organs, muscles, bones, and nerves basically give the water a place to hang out. Now, the interesting thing is that, aside from the hydrogen, the rest of the stuff all comes from stars. Some of those elements are cooked up inside stars like the Sun. Others come from stars that exploded as supernovae. Each of those kinds of stars spent a long time converting fuel to heat, and in their old age, they blew off clouds of material that included these elements.

The late astronomer Carl Sagan coined the phrase “We are star stuff” to explain how we came from the stars, albeit in a very long, long birth process. A bunch of stars had to live and die in order to make the “stuff” that is in our bodies, that makes up our planet, and even our Sun. It’s great stuff, this starstuff!