The above image is known as "The Horse's Head Nebula", its probably the most photograped image in astrophotography.
This type of nebula is where starbirth occurs.
The early stars of our Galaxy formed about 10 billion years ago. They didn't contain as many of the elements as our Sun does today. No carbon, no oxygen, and no iron. Before our Sun even formed, several generations of these heavy stars could have been through their entire life cycles, transmuting pristine hydrogen into the basic building blocks of life be flinging them back into space via strong winds or explosions.
This dust and atoms found itself in a dustcloud about 4.5 billion years ago, a newborn star condensed, surrounded by a dusty disc of gas, to become our solar system.
The carbon, oxygen and iron atoms in the solar system are from when the Sun formed from the nebula where it was born. These elements were made by heavy stars that had already died by that time.
These elements only made up 2% of these stars' mass. Hydrogen and helium were the dominant atoms.
Inside a nebula are young, hot blue stars. The rest is cold, dark and dusty.
Within it are warm "protostars" in the early stages of starbirth, contracting under their own gravity. Each is encircled by a disc of gas and dust.
To form a star, some of this gas must contract so much that its density rises a billion billion times. Any material left behind, gas and dust particles would collide regularly and would stick together and stick together and stick together to build up rocky lumps, which in turn would coalesce into larger bodies, which merge to make planets. Which is how our Sun and planets formed. The Earth would've been much larger then. In its early years, a mars-sized planet collided with it, breaking off a huge piece. The resulting dust from this collision would've left a ring system around the Earth, similar to that of Saturn and the other gas giants. The dust eventually compressed to form the moon.
