RES.8-007 | Fall 2019 | Undergraduate

Cosmic Origin of the Chemical Elements


Episode 2: What the Universe Is Made Of

After the Big Bang, the universe was composed of just hydrogen, helium, and tiny amounts of lithium. With time, heavier elements were forged in the many generations of stars. After about 8 billion years, the Sun was born, from gas that contained 1.4% of heavier elements. Today, this amount has increased to 2%. The Astronomer’s Periodic Table depicts the three most important constituents of the universe: X (= hydrogen), Y (= helium), and Z (= metals). (In the astronomical sense, “metals” refers to all the elements except hydrogen and helium.) 

Associated Book Chapters from Searching for the Oldest Stars: Ancient Relics from the Early Universe

  • Chapter 1: What Is Stellar Archaeology?
  • Chapter 2: Two Centuries of Pursuing Stars
  • Chapter 3: Stars, Stars, More Stars

Course Info

As Taught In
Fall 2019
Learning Resource Types
Lecture Videos
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