Lagoon Nebula

The Lagoon Nebula is a large emission nebula and star-forming region in Sagittarius, cataloged as Messier 8. Its glowing gas, dark dust lanes, and young stars make it a prominent Milky Way nebula.

Emission Nebula: An interstellar cloud that emits light after its gas is energized, usually by nearby hot stars. The Lagoon Nebula is a prominent example of this glowing nebula type.
Ionization: The process by which an atom or molecule gains or loses electric charge. Ultraviolet light from young stars strips electrons from hydrogen in the nebula.
Hourglass Nebula: A bright, hourglass-shaped region of ionized gas within the Lagoon Nebula. This compact structure is one of the nebula’s most distinctive star-forming features.
Charles Messier: An eighteenth-century French astronomer who compiled a catalog of nebulae and star clusters. Messier included the Lagoon Nebula as object 8 in his catalog.
H II Region: A region of ionized hydrogen surrounding hot, young stars. Ionized hydrogen produces much of the Lagoon Nebula’s characteristic red emission.
Hydrogen-alpha: A red spectral line emitted by hydrogen when an electron falls between specific energy levels. Hydrogen-alpha emission gives the Lagoon Nebula much of its red color in photographs.
Lagoon Nebula Star Cluster: The young open cluster NGC 6530 embedded in the Lagoon Nebula. Its hot stars illuminate and help disperse the surrounding gas.
Messier Catalogue: A catalog of nebulae, star clusters, and galaxies compiled by Charles Messier. The Lagoon Nebula’s familiar designation, M8, comes from this catalog.
Interstellar Dust: Microscopic solid particles mixed with gas between stars. Dust creates the dark lanes and obscures parts of the nebula.
Stellar Wind: A stream of charged particles flowing outward from a star. Winds from massive stars excavate cavities and compress gas within the nebula.

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