(Source of text: Astrodidact)
Messier 78, known as a reflection nebula located 1,600 light years away in the constellation of Orion. What makes this nebula a reflection nebula is that the energy released from a nearby star or group of stars is not strong enough to ionize the surrounding gases, which would make this an emission nebula. Instead, the dust we see here, shown as dark and blue, is far enough away from the energy of a star to where it is not ionized, but is in fact scattered, or reflected. For light to be scattered, that means that light waves hit some type of medium that distorts its trajection and forces it in another direction. The result of this scattered light is usually in the color or blue in our visible spectrum.