Infographic illustration depicting the contents of the universe. The largest components are dark energy (68%) and dark matter (27%) which have yet to be directly measured. The visible or measurable parts of the universe (free hydrogen, free helium, stars, neutrinos and heavy elements make up the remainder. Data based on measurements by the European Space Agency and the Brookhaven National Observatory. Percentages do not add up to 100 due to rounding and approximation.