More is unknown than is known. We know how much dark energy there is because we know how it affects the universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter - adds up to less than 5% of the universe. Come to think of it, maybe it shouldn't be called "normal" matter at all, since it is such a small fraction of the universe. . . . . . To know more visit: https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy . . . #nasafacts #nasa #facts #sciencefacts #sciencenerd #physicslove #physicsonly #physics #astronomyscience #astronomy #astrophysics #astronomyfacts #astrofact #darkmatter #darkenergy #universe #universefacts #universefact #universeknowledge #universetoday . . image credit : NASA https://www.instagram.com/p/CBMqHGRDg9h/?igshid=1g1mzwlgcubqf