The most important part of the nebula though is the opaque Orion Molecular Cloud, which cannot normally be seen from Earth. It is an enormous, concentrated amount of very cold gas with a mass of approximately 2000 times the mass of the Sun. Due to gravity, this cloud of hydrogen and other gasses slowly collapses and forms stars. The Molecular Cloud can be seen when new stars are forms, as the light evaporates the opaque gas of the Cloud.
The aforementioned Betelgeuse and Rigel are a part of what is called the Trapezium, a collection of very bright stars that are considered stellar siblings that are roughly the same age. When all the stars in the Orion Nebula are done being born, only the Trapezium will remain.
The Orion Nebula has been described for thousands of the years, beginning with the Mayans who used the Orion Nebula as a part of their creation myth. Interestingly, the great astronomers, Ptolemy, Al Sufi, and Galileo all excluded the nebula from their writings. The first scientific recording and classification as a nebula was by the French astronomer Nicolas-Claude Fabri de Peiresc in 1610. The first published observation though was by Jesuit mathematician Johann Baptist Cysat nine years after Nicolas-Claude Fabri. Robert J. Trumpler was the first to note the Trapezium cluster. The Hubble Space Telescope first observed the Orion Nebula in 1993, and since then, Hubble Space Telescope has been studying the nebula.
The nebula will continue to be a source of awe for humans for thousands of years. The beauty and importance of the nebula in star creation makes it a point of interest that we will undoubtedly value for a very long time.