
A canyon that catches ghosts
TAMBO will turn four and a half kilometres of Peruvian canyon into a telescope for the highest-energy neutrinos in the universe.
See how it worksThe detector is the landscape
No lens, no mirror, no tank of water. One wall of the canyon is four kilometres of solid rock that stops everything but neutrinos. The other carries five thousand detectors, watching the empty air in between.
- 4.5 km
- wall to wall
- the open air an air shower needs in order to grow
- 1.5 km
- deep
- enough rock on the far wall to filter out everything but neutrinos
- 5,000
- detector units
- spaced 150 metres apart across the near slope
- 1 to 3
- events a year
- a small number, but almost every one genuinely cosmic

Colca Canyon, Arequipa, Peru

Light gets lost. Neutrinos don't.
The most violent places in the universe — collapsing stars, matter falling into black holes — are wrapped in gas and dust that light cannot escape. Neutrinos pass straight through and arrive still pointing at whatever made them. TAMBO is built to catch the rarest and most energetic of them.
From a dying star to a hillside in Arequipa
Six steps explain the whole observatory. Each one is built as something you can play with rather than read.
- 01
Why neutrinos?
Photons get absorbed on the way. Protons get bent by magnetic fields until their direction is meaningless. Only neutrinos arrive pointing back at whatever made them.in progress
- 02
Ghost particles
Trillions pass through your body every second without touching a single atom. Raise their energy far enough, though, and even the Earth turns opaque.in progress
- 03
The canyon trick→
A tau neutrino skims through a mountain and turns into a tau lepton. The tau escapes into open air, decays, and its decay becomes a shower of particles raining across the valley.
- 04
Reading the shower
Five thousand detectors record how many particles arrived and precisely when. Out of those arrival times comes the neutrino's direction, to better than a degree.in progress
- 05
Patience and purity
One to three events a year sounds like failure next to IceCube's thousands. It isn't: TAMBO's handful are clean, and a clean event tells other telescopes exactly where to look.in progress
- 06
Why this canyon?
The Colca Canyon in Arequipa, Peru, and the communities who live along it — who are part of the project by design, not by consultation after the fact.in progress

The canyon is not empty
Villages, terraces farmed for centuries, and the communities of Arequipa. TAMBO's collaboration includes anthropologists, historians and geographers alongside physicists, because where an observatory goes is a question about people before it is a question about rock.
Tambo means inn
Tambos were the way-stations built along Inca roads, where messengers running through the mountains could stop and rest. This one is a resting place for messengers of a different kind — neutrinos that have crossed the universe carrying news from the most violent events in it.
