عندما تقولها لذوي التسعة اعوام يكون السؤال، "اذا كان كويكب ليضرب الارض، كيف نعرف اذا كان سيصيب ام لا؟"
The way you would put it to a nine-year-old is to say, "If a meteorite was coming to hit the Earth, how would you figure out if it was going to or not?"