The Earth formed over 4.6 billion years ago out of a mixture of dust and gas around the young sun. It grew larger thanks to countless collisions between dust particles, asteroids, and other growing ...

Unlike Earth, the moon’s cooling crust formed a thick layer of feldspar, giving rise to the bright highlands visible today. Volcanic eruptions on the moon produced vast basaltic plains ...

More than 4,000 naturally occurring minerals—inorganic solids that have a characteristic chemical composition and specific crystal structure—have been found on Earth. They are formed of simple ...