The ordinary matter may only make up 5 percent of the mass of the Universe, but that doesn’t necessarily mean we know where it all is. In fact, for 20 years, astronomers have been trying to figure out why there isn’t as much as there should be. Now researchers have put their heads together to solve the missing baryon problem, and found it, floating around in the space between the stars. Using computer simulations, researchers are hoping to tell us how many total baryons ought to exist in the cosmos, along with the ratios of light elements to hydrogen.