Matter in the universe (IMAGE) University of California - Riverside Caption The team determined that matter makes up about 31% of the total amount of matter and energy in the universe. Cosmologists believe about 20% of the total matter is made of regular -- or "baryonic" matter -- which includes stars, galaxies, atoms, and life, while about 80% is made of dark matter, whose mysterious nature is not yet known but may consist of some as-yet-undiscovered subatomic particle. Credit Mohamed Abdullah, UC Riverside. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.