An Etymological Dictionary of Astronomy and Astrophysics

A massive (3 × 10⁶ → solar masses), dense (up to 10⁸ particles per cm³) → H II region and → molecular cloud complex located near the → Galactic center (about 390 → light-years from it) and
about 26,000 light-years from Earth. This complex is one of the largest in the → Milky Way, spanning a region about 150 light-years across. The mean → hydrogen  → density within the cloud is 3,000 atoms per cm³, which is about 20-40 times denser than a typical molecular cloud. It is the richest molecular source in the Galaxy in which many different types of → interstellar molecule have been identified, including glycine, the simplest amino acid, and the sugar molecule glycoaldehyde.

See also: → Sagittarius.