When you think of space, you think of emptiness. You probably could not be more wrong. Using the 54km of underground tubes and tunnels that is the LHC we explore the vacuum. In an environment where the air pressure is lower than on the moon, it is quite possibly the best vacuum humanity can produce.
Extremely low energy, but definitely not empty. The vacuum of space is populated by virtual particles which pop in and out of existence on a time scale that is undetectable by our current technology. This odd appearance is allowed by the laws of quantum mechanics.
Energy is also added to the vacuum through the interaction of quark-antiquark pairs (chiral condensate) which contribute mass to particles, which can be thought of as energy. Chrial condensate is something that the LHC is very interested in studying through use of the ALICE experiment.
The Higgs: the fluctuating quantum fields are not the only thing filling the ‘empty’ vacuum of space. The Higgs field is omnipresent and permanent and is thought to be responsible for the mass of all fundamental particles. The Higgs boson is the accompanying particle and would definitively prove the Higgs field if detected.
The energy of the vacuum is something quite different on the astronomical scale, instead of minuscule points of undetectable energy, it becomes the mammoth and unknown dark energy. Current predictions for the expansion of the universe do not hold with new observations and the LHC is hoping to learn some more about dark energy so that we can reconcile our modern observations with physics.