“As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days).Because it includes the word "year", the term light-year may be misinterpreted as a unit of time.”
but if you had a big enough telescope and managed to put a mirror out there, 10 light years away, . You'd have to wait, but in 20 years, it would be reflecting light back.
Comments