M 8 is a galactic nebula, an H II region, the birthplace of new stars. The most notable detail is the dark curved channel that crosses the nebula from NE to SW, seemingly splitting it in half.
The exact distance from M 8 is still somewhat uncertain, due to the strong different darkening in this region of the galaxy. Distances range from about 3000 to 5200 light years.
At this distance, the bright areas of the nebula extent of around 66x44 light years. If the weaker outer region is included, the nebula grows to around 115 light years.
M 8 appears to be part of a larger nebula complex, which also includes the Trifid Nebula (north) and the nebulae NGC 6559 and IC 4681 (east).
All of them are connected to one another by a delicate veil of gas and dust.
The eastern part of the galactic nebula Messier 8 contains the young open star cluster NGC 6530 and is in front of the Lagoon Nebula.
The age is estimated at a few million years.
