The Lagoon Nebula (M8) is an emission nebula in the constellation Sagittarius (Sagittarius).
The nebula itself was discovered in 1747 by Guillaume Le Gentil, the open star cluster NGC 6530
that forms its center as early as 1680 by John Flamsteed. It is not entirely clear which object
was included as number 8 in his catalog by Charles Messier, nowadays it is assumed that the
entire nebula was meant. The nebula is very vast, its apparent size being 3 × 1½ times that
of the Moon, which equates to 140 × 60 light-years at a distance of 5200 light-years.