On March 19, Earth’s satellite will be at its closest point to our planet in 18 years -- a mere 356,577 kilometers away. The event -- also called a lunar perigee -- was dubbed a "supermoon" by astrologer Richard Nolle back in the 1970s. The term is used to describe a new or full moon at 90% or more of its closest orbit to Earth. Next week, it will be at 100%.