After more than a month of checking out the equipment, the Large Hadron Collider is set to return to the frontiers of particle physics. This will be the second run at higher energies after a few years at lower energy and a couple years of upgrades. The plan for this year is to increase the frequency of high-energy collisions in order to get a better view of the Higgs boson and pursue the search for new particles.

After suffering a catastrophic failure early in its history, the LHC was run for several years at energies that created collisions at seven or eight Tera-electronVolts. This was followed by an extended shutdown that upgraded hardware and fixed the defects that caused the earlier failure. Last year's physics run was the first at 13TeV, and the collider's operators were relatively cautious as they learned how to control the machine at these higher energies.

The new energies provide two major advantages. Since new particles are created by converting energy to matter, the higher the energy, the heavier the particles you can produce. And some analyses have been finding hints that there might be a new particle in the neighborhood of 750 Giga-electronVolts—nearly 800 times the mass of the protons that were smashed to create it.

But the high energies also increase the probability of producing heavy but substantially lower-mass particles. These include the Higgs boson, which weighs in at about 125GeV. By producing the Higgs in much higher numbers, we can start getting more precise measurements of its properties and test them against our theoretical expectations.

Beyond energy, the other way to see more of a particle is to simply increase the number of collisions, called the luminosity. That's the goal of this year's run. The LHC circles its protons in bunches, so you can boost the luminosity by increasing the number of bunches, putting more protons in the bunches and/or squeezing the bunches down so that the proton density is higher. The LHC's operators had already reached the maximum number of bunches, and they will focus on boosting luminosity through the other two approaches, with the goal of squeezing out six times the number of collisions into this year's run.

Of course, random events can get in the way of those sorts of goals. Testing of the hardware suffered a multi-day delay when a small marten (a member of the weasel family) found its way into the hardware that supplies the machine with power, ending his life in a way that the collider required major hardware repairs.