The HorseHead Nebula

The Horsehead and Flame Nebula!  Also known as Barnard-33, the Horsehead Nebula is an iconic celestial object around 1,500 light years away from Earth and is located in the constellation of Orion. I vividly remember getting fascinated when I first saw this as a child in a documentary.

Here's what Wikipedia says about this object - Heavy concentrations of dust in the Horsehead Nebula region and neighboring Orion Nebula are localized into interstellar clouds, resulting in alternating sections of nearly complete opacity and transparency. The darkness of the Horsehead is caused mostly by thick dust blocking the light of stars behind it. The lower part of the Horsehead's neck casts a shadow to the left. The visible dark nebula emerging from the gaseous complex is an active site of the formation of "low-mass" stars. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming.