Standing on the Ashes of a Star

Here’s Your July Assignment

A color image of Earth as seen from Apollo 17.

Take a hike. No, really. Go out for a hike somewhere and closely examine the rocks and soil you encounter. If you live near mountains, look at them and imagine them as they were when they were young. Then, think about where all this stuff came from. If you go back to almost first principles, you find out that what you’re seeing and hiking on is the leftovers of star formation. That’s because sometimes planets are what’s left after a star forms. And, in the case of our four inner planets, the leftovers became worlds we know and love.

The elements in those rocks, the ones that make up the plants and animals you see on yourhike, and you yourself, are all part of stuff that was a star–ashes that were recycled into the Sun and somehow made it into the soup of stuff that created Earth. Quite a cool thing to think about when you’re out hiking.