This one’s looking for particles, not stars.

One of the rarest phenomenons in the known universe is the appearance of a neutrino particle. Neutrinos are almost like real-life spirits, as they possess the ability to fly through incredible stretches of space, as well as solid matter, without ever actually touching anything. Millions of neutrinos fly through you on a regular basis, you just can’t see them because they’re too fast. This is why it’s understandably difficult to get a look at them for study. If you can’t get a precise view of a particle from one angle, though, you need to try more angles. A lot more angles.

Credit: KM3NeT

An international collaboration of researchers is currently underway deep beneath the Mediterranean sea. Scientists from all over the world are busily constructing the Cubic Kilometre Neutrino Telescope, also known as “KM3NeT.” Contrary to what the name may imply, KM3NeT is not a telescope in the traditional sense. Rather, it’s an array of sensors staring down at the Earth’s center (down being relative to us on the planet). Particles fly through the ocean all the time, but only a neutrino would be capable of flying up through the Earth’s crust, and when one does, KM3NeT can catch it in the act. But why are they building it at the bottom of the ocean? Because ocean water is a good insulator against radiation, which messes with neutrinos, providing the best possible picture.

Construction and tests have been running since last year, and will likely continue for quite a while. When KM3NeT is finished, it will occupy approximately a cubic kilometer of seawater. That’s as much space as 400,000 Olympic-grade swimming pools. It’s a large-scale effort, to say the absolute least, but no mission is too big in the pursuit of scientific discovery.