The Large Hadron Collider is the most advanced and complex machine ever built by humanity, and it’s allowed us to study the inner workings of the universe in unprecedented ways. However, there’s only so much you can do with a 27-kilometer particle collider. So, CERN has approved plans to build a much larger collider called the Future Circular Collider (FCC) with a 100-kilometer (62-mile) circumference.

Physicists have made many predictions about the nature of the universe and the existence of exotic particles. The best way we know to expose these particles to test theories is to smash protons together at high speeds and see what comes out. That’s how the Large Hadron Collider confirmed the existence of the Higgs Boson in 2012. Generally, higher collider power means more particle detections. The LHC produced the Higgs results with 13 125–126 GeV of energy, but the instrument can run at 13 TeV (an order of magnitude more). An ongoing upgrade will push the LHC even further, but the FCC will dwarf this instrument with a predicted collision energy of 100 TeV.

When the FCC is up and running, it will be able to spit out Higgs bosons on demand, allowing scientists to map the way these particles interact with other matter. The first iteration of the FCC will rely on electron-positron collisions, which is ideal for producing Higgs particles. After that, the team will upgrade the instrument to handle proton-proton collisions, reaching its full 100 TeV potential. 

Planning for the LHC began in the early 1990s, and principal construction kicked off in 1998. However, CERN had the advantage of upgrading an existing facility to make the LHC a reality. The 27-kilometer tunnel that houses the LHC beam path was originally built in the 1980s for the Large Electron-Positron Collider. The FCC will require an entirely new construction project to bore out a 100-kilometer underground ring, and that won’t start until 2038 at the earliest. So, we’re probably looking at the mid-21st century before the FCC is doing science. 

The project could eventually cost upward of $23 billion, which is more than CERN can gather from its European partners. The organization might need to partner with the US, China, or Japan. However, it could finally shed light on some of the most vexing conundrums in physics, such as the higher prevalence of matter compared with antimatter and the composition of dark matter.