Researchers at GRAPES-3 muon telescope facility in Ooty measures electrical potential, size and height of a thundercloud

For the first time in the world, researchers at the GRAPES-3 muon telescope facility in Ooty have measured the electrical potential, size and height of a thundercloud that passed overhead on December 1, 2014. The study of thunderclouds is helpful in navigation of aircraft and preventing short circuits in aeroplanes. At 1.3 gigavolts (GV), this cloud had 10 times higher potential than the previous record in a cloud. This is not because clouds with such high potentials are a rarity, but rather, because the methods of detection have not been successful so far. The structure of Cloud is that clouds have negative charges along their lower side and positive charges on top and can be several kilometres thick. If balloons are used to measure the potential difference between the top and bottom, they will take hours to traverse the distance. Unfortunately, thunderstorms last only for about 15-20 minutes, and this method fails. The GRAPES-3 experiment (or Gamma Ray Astronomy PeV EnergieS phase-3) located at Ooty in Tamil Nadu and is designed to study cosmic rays with an array of air shower detectors and a large area muon detector.