Electronic display of a cosmic ray neutrino event in the IMB proton decay detector. The detector is tank of ultrapure water 600m underground in a salt mine in Ohio. Its walls are lined with phototubes which detect flashes of Cerenkov light emitted as a result of particle interactions. The display shows the location of each tube that is triggered by a coloured star; the number of slashes in each star denotes the number of photons recorded; the colour represents time - red for the first tubes triggered, blue for the last. Neutrinos can pass right through Earth. This one interacted in the IMB's water, creating a circle of stars at bottom. (June '84)