To investigate some of the biggest mysteries in the universe, particle physicists design and build high-tech detectors. On top of the incredible science they make possible, these experiments are often staggeringly beautiful. Views of the process of putting them together look like they could come straight out of a sci-fi film or from an alien planet.

This is true of the ProtoDUNE detectors, which often appear in photographs as giant gold-colored cubes. These test beds are how scientists assess the technologies that will go into the Deep Underground Neutrino Experiment, the biggest international science project in the United States.

Hosted by the US Department of Energy's Fermi National Accelerator Laboratory, DUNE will send particles called neutrinos 800 miles (1300 kilometers) through the earth from Illinois to South Dakota. There, about a mile (1.5 kilometers) underground, the largest liquid-argon neutrino detector ever built will analyze how those neutrinos behave. Researchers will use the data to investigate some of the biggest unsolved mysteries in particle physics, including why matter exists and what role neutrinos played in the universe’s evolution.

DUNE is an international endeavor with 1100 scientists and engineers from more than 30 countries. DUNE is supported by international funding agencies, including the DOE Office of Science. The prototype detectors for DUNE are under construction at the neutrino platform at CERN, the European Center for Nuclear Physics and home of another amazing science machine, the Large Hadron Collider.

The two ProtoDUNE detectors will help finalize the two different technologies that will be used for the four modules that will comprise DUNE’s far detector and will be filled with 70,000 tons of liquid argon.

Take a look at the construction and evolution of the two prototypes in these 20 photographs—and keep in mind that each of the final DUNE detector modules in South Dakota will be 20 times bigger.