KM3NeT: An Underwater Telescope Revealing The Secrets Of Neutrinos

Innovative network of underwater detectors in the Mediterranean to study elusive cosmic particles and explore the Universe from a new perspective

In the heart of the Mediterranean Sea, at a depth of 3,500 meters, one of the most ambitious scientific projects of our time is being realized: the underwater telescope KM3NeT, an acronym for Cubic Kilometer Neutrino Telescope. This next-generation research infrastructure will revolutionize our understanding of the Universe through the study of neutrinos, elusive subatomic particles that are fundamental to modern astrophysics.

Expanded infrastructure of optical modules offshore France, Italy and Greece

KM3NeT is designed as a series of underwater telescopes located at several locations in the Mediterranean Sea, with the main ones located off the coasts of Italy, France and Greece. Once completed, the project will include thousands of optical modules organized into a three-dimensional array capable of detecting the weak Cherenkov light produced by neutrino interactions with seawater. This configuration will allow observations of water volumes of several cubic kilometers, providing unprecedented sensitivity in detecting high-energy neutrinos.
The choice of the Mediterranean Sea as the location for KM3NeT is no accident: its deep and transparent waters are ideal for detecting Cherenkov light, and its geographical location provides optimal coverage for studying neutrinos coming from various cosmic directions.

Important scientific goals and applications in the ARCA and ORCA experiments

The KM3NeT telescope is designed to conduct two main scientific studies: neutrino astrophysics (ARCA) and neutrino physics (ORCA).

Neutrino Astrophysics (ARCA)

With the Astroarticle Research with Cosmics in the Abyss (ARCA) detector, scientists aim to detect neutrinos coming from distant astrophysical sources such as supernovae, gamma-ray bursts, or stellar collisions. These observations could provide important information about the most energetic processes in the Universe and contribute to our understanding of the origin of cosmic rays. Neutrinos, as neutral and nearly massless particles, can travel throughout the Universe without being deflected by magnetic fields or absorbed by matter, making them ideal messengers for studying distant cosmic phenomena.

Neutrino Physics (ORCA)

The ORCA (Oscillations with Space in the Abyss) detector is designed to study the fundamental properties of neutrinos using properties generated in the Earth’s atmosphere. In particular, ORCA will focus on determining the neutrino mass hierarchy, one of the most pressing open questions in modern particle physics. Understanding how neutrinos oscillate between their three “flavors” (electron, muon, and tau flavors) is critical to completing the Standard Model of particle physics.

A truly revolutionary discovery: a neutrino with an energy of about 220 petaelectronvolts (PeV)

On February 13, 2023, the ARCA detector at the KM3NeT observatory recorded an unusual event: the detection of a neutrino with an estimated energy of about 220 petaelectronvolts (PeV), which is the highest energy ever observed to date. These results, published in the journal Nature, have generated great interest among the scientific community, as they demonstrate the existence of cosmic processes capable of accelerating particles to very high energies. The origin of these neutrinos remains uncertain, but it is hypothesized that they may be of extragalactic origin, such as blazars (active galactic nuclei) or may be the result of interactions with remnants of the cosmic microwave background radiation.
This discovery not only confirms the effectiveness of KM3NeT as a research tool, but also opens up new questions about the nature of cosmic neutrino sources and the physical mechanisms that produce them.

International cooperation and future prospects for other countries of the world

KM3NeT is a shining example of international scientific collaboration involving research institutes and universities from different European countries, primarily Italy, France and Greece, but also from twenty other countries around the world: the Netherlands, Spain, Germany, Belgium, Poland, Romania, Ireland, the United Kingdom, Egypt, South Africa, Australia, the United States, Switzerland, Croatia, Hungary, Armenia, Tunisia, Morocco, Georgia and Russia.
In particular, the Italian National Institute for Nuclear Physics (INFN) plays a leading role in this project, with the support of the Ministry of University and Research and the Sicilian Region.
The international collaboration is not limited to the construction and operation of the infrastructure, but also includes the exchange of data and scientific results, facilitating a global approach to neutrino research. Once the ARCA and ORCA detectors are completed and operational, KM3NeT will become one of the world’s leading infrastructures for neutrino research.

Major advances in marine geophysics, marine biology and underwater engineering

Beyond neutrino physics, the cubic kilometer neutrino telescope could revolutionize other areas of research. The technology developed for underwater telescopes could have significant implications in areas such as:

Marine Geophysics : The KM3NeT sensor can be used to monitor underwater seismic and volcanic activity, helping to improve earthquake and tsunami forecasts;

Marine biology: The infrastructure can be used to study deep-sea ecosystems, including bioluminescent organisms and deep-sea biodiversity;

Underwater technology: Technologies developed for KM3NeT, such as underwater communication systems and high-pressure resistant materials, can be applied in the marine industry and environmental protection.

KM3NeT and Future Challenges: Unlimited Scientific and Technological Horizons

The KM3NeT project is expected to be completed in 2030 and will become a pillar of international scientific research. Its discovery may actually contribute to answering fundamental questions about the nature of dark matter and dark energy, as well as the origin and evolution of cosmic structures.
In addition, this project is an example of how fundamental research can lead to technological innovations with wide practical applications, demonstrating the value of science as an engine of human progress.
In short, the underwater telescopes deployed in the Mediterranean waters of France, Italy and Greece represent an outstanding scientific and technological endeavor, destined to leave an indelible mark on our understanding of the Universe and to contribute to the development of new technologies for the benefit of society.