Answer:
Dark matter and dark energy
Step-by-step explanation:
Dark matter is thought to make up about 85% of the mass-density make up the universe. Dark matters have not been observed by direct interaction, but indirectly by their interaction with the universe generally; producing some gravity effect that cannot be explained by the existing gravity laws except there is more matter in the universe than is accounted for. Dark energy is an unknown, and undetected energy that is thought to exist in the universe, and affects the universe on the largest scale. The existence of dark energy is the only explanation for why the universe is seen to be expanding at an accelerated rate, rather than at a constant rate. These two element (dark matter and dark energy) make up a very large energy-mass portion of the observable universe.