Messier 8 — Emission Nebula in Sagittarius

The Lagoon Nebula is one of the brightest and largest nebulae in the sky, located about 4,100 light-years away in the constellation Sagittarius. It is a giant interstellar cloud of gas and dust spanning about 110 by 50 light-years, with an associated young open cluster (NGC 6530) of about 50-100 hot young stars that illuminate the nebula. The prominent dark lane running through the center — which gives the nebula its 'lagoon' appearance — is a region of dense, obscuring dust.

Located in a rich part of the Milky Way in Sagittarius, about 5 degrees north of the 'lid' of the Teapot asterism. Visible to the naked eye as a bright patch from dark sites. Binoculars reveal a large, bright nebula with the embedded star cluster NGC 6530. In a telescope at low power, the dark lagoon channel is clearly visible bisecting the nebula. Higher power reveals the Hourglass Nebula — a bright, compact region of turbulent gas near the center. Use a UHC or OIII filter to enhance nebular detail. Best observed from June through August when Sagittarius is at its highest.

Discovered by Giovanni Hodierna before 1654, making it one of the earliest nebulae observed telescopically. Independently discovered by John Flamsteed around 1680 and by Philippe Loys de Cheseaux in 1746. Charles Messier cataloged it in 1764. The Hourglass Nebula within M8 was first described by John Herschel, who also gave the Lagoon Nebula its common name.