Neutrinos, not light

TAMBO's aim is to detect tiny cosmic particles, called neutrinos, produced at extremely high energies in energetic explosions in the distant universe.

Just like normal telescopes, TAMBO's goal is to map and understand our universe. Unlike normal telescopes, however, TAMBO will see neutrinos, not light. Because neutrinos interact very rarely, they can reach us even from the depths of the distant universe, regions so distant and dense that light-based signals would be blocked. In this way, TAMBO will study phenomena previously unseen and unknown.

In addition to its astronomical aims, TAMBO also aims to give new insights into the fundamental physics of neutrinos. The discovery of the neutrino is now over seventy years old, but because it is so difficult to detect, many of its characteristics remain unknown and mysterious. In particular, the tau flavour of neutrinos, which is the target of TAMBO, has been identified experimentally only about twenty times.

TAMBO's science thus spans the very largest and very smallest scales.

What we are looking for

Discovering cosmic neutrino sources

Because of their high energies and tau flavour, the neutrinos detected by TAMBO will be exclusively cosmic in origin. By reconstructing the direction these neutrinos came from, TAMBO will be able to build lists of candidate source locations. Those lists can then be used by lower-energy, higher-rate telescopes such as IceCube, KM3NeT and Baikal-GVD to search their archival data. Since every previous neutrino source discovery has relied on a gamma-ray or optical counterpart, this could enable the first neutrino-only source discoveries in astronomy.

Searching for cosmogenic neutrinos

TAMBO will also be sensitive to some models of the long-theorised flux of cosmogenic neutrinos, produced when the highest-energy cosmic rays collide with the cosmic microwave background and extragalactic background light. The models TAMBO can reach predict fluxes peaking around 100 PeV — a region made newly interesting by puzzles such as KM3NeT's recent 220 PeV event.

Extending the diffuse measurement

TAMBO will be sensitive to neutrinos from PeV to EeV energies. Its sensitivity there is competitive with all-flavour measurements, and exceeds those of currently operating observatories when only identifiably tau neutrinos are considered. TAMBO will therefore be able to make new measurements of how the diffuse astrophysical tau neutrino flux depends on energy.

Testing fundamental physics

TAMBO will probe neutrino–nucleon cross sections at unprecedented energies, constrain the flavour composition of the cosmic neutrino flux, and search for physics beyond the Standard Model.

Tackling the cosmic-ray muon puzzle

Using the surrounding rock formations as a natural shield, TAMBO may be able to measure the electromagnetic and muonic components of air showers separately, shedding light on a long-standing discrepancy between cosmic-ray simulations and data.

Read the proposal

The full case for the observatory is set out in the TAMBO proposal, published in Nature Astronomy, and in the collaboration's papers.

arXiv:2507.08070 arXiv:2606.11230