Astrophysicists have performed a new survey of the quantity of matter in the cosmos, revealing that 31% of our universe is made up of matter.

"To put that amount of matter in context, if all the matter in the universe were spread out evenly across space, it would correspond to an average mass density equal to only about six hydrogen atoms per cubic meter [about 35 cubic feet]," Mohamed Abdullah, a graduate student in the Department of Physics and Astronomy at the University of California, Riverside (UCR), said in a statement.

But since we are aware that 80% of matter is essentially dark matter, much of this matter is essentially not hydrogen atoms, but rather a form of matter that cosmologists do not yet understand, said Abdullah, who led a new study announcing the outcome.

The research, reported online on Sept. 25 in The Astrophysical Journal, indicates that 69% of the matter-energy budget of the cosmos is dark energy, a mystical force believed to be responsible for the accelerating expansion of our universe.

That number is in rough accordance with previous figures that have been determined by astronomers through a range of methods. The team behind Europe's Planck satellite, for instance, which investigated the cosmic microwave background, the illumination left over from the Big Bang, decided in 2013 that 68.3% of the universe is dark energy.

The latest research also reaffirms the comparatively small 5% contribution of regular matter, which makes up stars, planets, plants, oceans, and everything else we can see and touch directly.

By analyzing galaxy clusters, the research team arrived at their total. By observing the orbits of the component galaxies, the researchers created a mechanism that estimates the mass of a cluster. They applied this method to the Sloan Digital Sky Survey findings, a wide-ranging campaign using a New Mexico telescope, generating a cluster catalog that the researchers then correlated with empirical simulations.

The research team clarified that such a distinction between observed cluster numbers and masses and modeled projections is an established technique for calculating the total matter content of the universe. That's because clusters are a type of cosmological probe that takes billions of years to develop. Their observed numbers are subject to a variety of variables, particularly the total matter content of the universe.

The 31% figure is indeed a "best combined value" that Abdullah and his team found following combining their cluster findings with previous assessment done by way of a smattering of methods.