One of the highlights of the summer sky is a cloud of gas called the Lagoon Nebula. It is barely visible to the unaided eye, but easily seen with a pair of binoculars. The pink color is due to the presence of hydrogen gas, excited by hot stars within the cloud. There is also a little blue coloring mixed in where starlight is reflected by embedded dust. A dark dust band divides the cloud in two parts. The star cluster NGC 6530 is visible at the left.