The most persuasive evidence that Voyager 1 has crossed the termination shock is its measurement of a sudden increase in the strength of the magneticfield carried by the solar wind, combined with an inferred decrease in its speed.
Mr Wechlin adds that, during charging time, people stay inside the buses - something he says is absolutely safe, as the strength of the magneticfield produced is within the limits recommended by the International Commission on non-ionizing radiation protection (ICNIRP).