Longest lunar eclipse in nearly 600 years Friday

(Houston, TX) -- The longest lunar eclipse in nearly 600 years takes place this week.  

NASA says a near-total lunar eclipse will be visible across North America early Friday, leaving nearly 97-percent of the full Moon in a dark shadow with only a sliver of light on its left side.  The eclipse will last for about three-and-a-half hours, peaking at about 4 a.m. Eastern Friday morning.  

Astronomers say it's the longest partial lunar eclipse in about 580 years.