If a star is 10 light-years away from us and it explodes today, when will we know that it exploded?
today
10 years from today
10 parsecs from today

Respuesta :

Well, one light year is the distance in which light travels in one year. So, if a star is 10 light-years away from us, and it explodes today, we will know that it exploded 10 years from today.