What makes up more than 85% of the total matter in the universe yet it cannot be seen? Dark matter.
According to the US Department of Energy article, DOE Explains Dark Matter, we know little about it other than that it only interacts with ordinary matter through gravity. Despite our lack of knowledge, scientists do have overwhelming indirect evidence for dark matter. One of the facts that scientists agree upon is that dark matter played a very important role in the formation of the universe.