Mineral prospecting involves a good amount of punting. Determining where the drill bit hits the ground is largely educated guesswork. Now, there is help coming to strengthen this guesswork — and it is coming from the skies. In the future, when mining engineers set out to locate mineral ores hidden deep inside the earth, they will have assistance from an unlikely quarter — space.

Exploding stars — supernovae — send streams of protons across space; some of them reach earth’s atmosphere, collide with particles and turn into ‘muons’. According to the US Department of Energy, one muon hits every sq cm of the earth every minute. Muons live for microseconds, but that is enough for them to plough through the ground. Their trajectories depend on the density and atomic composition of the material they traverse, a property that is used to generate 3D images of the structures they penetrate.

Muon tomography, a decades-old technique back in business today thanks to improved sensors and computing, is being sought after by mining companies. Rio Tinto, BHP and NexGen (a uranium miner) have all signed up for the services of Canadian company Ideon Technologies to access ‘subsurface intelligence’.

A recent paper by two researchers at the University of Texas notes that muon tomography has already demonstrated effectiveness in diverse applications. Other than mineral prospecting, the technique can be used to detect, for example, hidden nuclear material, the researchers say.

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Published on April 20, 2026