What is the universe made of? Astronomy Introduction to Astronomy Astronomy Basics 1 Answer George C. Feb 9, 2017 #90#% hydrogen, #10#% helium, trace amounts of everything else. Explanation: The chemical composition of the universe is about #90#% hydrogen, #10#% helium and tiny proportions of all other elements. Answer link Related questions Why do astronomers use scientific notation to describe sizes? What is astronomy? What types of jobs are available for those who hold a degree in astronomy? What is the meaning of the word astronomy? How would you calculate the energy of a photon with a known frequency? What is the difference between astronomy and astrology? What schools are renowned for their astronomy programs? What is a meteor? What occupations are there in the astronomy field? How is the acceleration of gravity calculated for planets? See all questions in Astronomy Basics Impact of this question 1478 views around the world You can reuse this answer Creative Commons License