Messier 20 and 21 . ... About 5,000 light-years away, the colorful study in cosmic contrasts shares this well-composed , nearly 1 degree wide field with open star cluster Messier 21 (top right). Trisected by dust lanes the Trifid itself is about 40 light-years across and a mere 300,000 years old. ... In fact, M21's stars are much older, about 8 million years old . ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ... A service of: LHEA at NASA / GSFC . ...