Lagoon Nebula

M8: The Lagoon Nebula in Sagittarius (NGC 6523)

Object type: Emission (H II region) nebula
Distance from Earth: 4,000 light years
1,200 parsecs
Distance across Nebula: 30 light years
9.2 parsecs

The Lagoon Nebula is mainly hydrogen gas left over from the star formation of NGC 6530, a star cluster near the middle of the Lagoon. The expanding gas collides with dark matter nearby, making bright rims of gas surrounded by dark clouds. One dark cloud cuts across the middle of the nebula, making it look like a lagoon. The nebula is approximately 2 million years old, which is considered young on a cosmic scale.