text: Scientists have used cosmic rays from the distant universe to study lightning and thunderclouds in unprecedented detail. Cosmic rays constantly bombard Earth’s atmosphere, and there have been some suggestions they could even trigger lightning. But this particular experiment observed how cosmic rays were affected by lightning as they passed through it - providing information on the electrical field of a given storm. Scientists in The Netherlands were using the Lofar radio telescope. They found it could measure changes in lightning caused by cosmic rays (illustrated). A storm can have hundreds of millions of volts over multiple kilometres. The method could provide a novel way to understand thunderclouds . The experiment was conducted using the Lofar (Low-Frequency Array) radio telescope in the Netherlands. Researchers found, almost by accident, that cosmic rays were a suitable probe to measure electric fields within thunderclouds. High in the atmosphere, the rays strike atmospheric molecules and create ‘showers’ of elementary particles - the smallest known to exist. A long-standing puzzle in astrophysics is the source of ultra-high-energy particles from space that hit Earth. Called cosmic rays, they're up to a billion times more energetic than particles at Cern's Large Hadron Collider. They strike the atmosphere and cause an enormous shower of other particles, mostly muons, electrons and photons, over a wide area. Though they were discovered decades ago, cosmic rays at these high energies are very rare, making it difficult to pinpoint where in the universe they originated. It's thought that some come from supernovae, but it's likely there are other sources of cosmic rays in the universe as well. These showers can be measured from the radio emissions that are generated when they interact with Earth’s magnetic field. By measuring this during a thunderstorm, the researchers found they could find out information about the electric field in a thundercloud as it affected the radio emissions. It was found to be as strong as 50 kilovolts per one metre (3.3ft) - which translates into a voltage of hundreds of millions of volts over multiple kilometres, an enormous amount of energy. 'We modeled how the electric field in thunderstorms can explain the different measurements,’ said researcher Dr Pim Schellart from Radboud University in the Netherlands. ‘This worked very well. How the radio emission changes gives us a lot of information about the electric fields in thunderstorms. ‘We could even determine the strength of the electric field at a certain height in the cloud.’ Though they were discovered decades ago, cosmic rays at these high energies are very rare, making it difficult to pinpoint where in the universe they originated. It's thought that some come from supernovae (illustrated), but it's likely there are other sources of cosmic rays in the universe as well . Lightning is a highly unpredictable natural phenomenon that inflicts damage to infrastructure and claims many victims around the world each year. This new method to measure electric fields in thunderclouds will contribute to a better understanding and ultimately better predictions of lightning activity. Current measurement methods from planes, balloons or little rockets are dangerous and too localised. Most importantly, the presence of the measurement equipment influences the measurements too. Cosmic rays probe the thunderclouds from top to bottom. Moving at almost the speed of light they provide a near instantaneous 'picture' of the electric fields in the cloud. Moreover, they are created by nature and are freely available. 'This research is an exemplary form of interdisciplinary collaboration between astronomers, particle physicists and geophysicists', said Dr Heino Falcke, also from Radboud University. 'We hope to develop the model further to ultimately answer the question: how is lightning initiated within thunderclouds?' Lightning (shown in Utah) is a highly unpredictable natural phenomenon that inflicts damage to infrastructure and claims victims around the world. This new method to measure electric fields in thunderclouds will contribute to a better understanding and ultimately better predictions of lightning activity .
target: Scientists in The Netherlands were using the Lofar radio telescope .
  They found it could measure changes in lightning caused by cosmic rays .
  A storm can have hundreds of millions of volts over multiple kilometres .
  Method could provide a novel way to understand thunderclouds .