Even the Milky Way has an heart and a soul!

These two picturesque nebulae are located 6,000 light-years away from Earth, in the direction of the constellation Cassiopeia. The Heart Nebula (IC 1805) is on the right, while the Soul (IC 1848) is on the left. These two, along with other smaller surrounding nebulae, form a complex star-forming region.

According to some theories about 10 million years ago part of the Heart Nebula would have been crossed by an ionization wave that would have triggered the first phenomena of star formation. As in a chain reaction, these phenomena would later spread to other regions, thus causing the formation of a large number of stars.

According to other theories, however, the star formation inside the nebulae occurred independently and not following a chain reaction.

What is certain is that the ultraviolet radiation and stellar wind produced by the young stars have shaped the gases of the nebulae, making them take on the shape we see today.

Credit: David Lindemann.