Page 62 in your Handmade, personalized Fine Art Book You and the Universe:

Above is an artist’s concept of a young solar system. In the center is a protostar, a stage in the development of a star after it has started to contract within a solar nebula. This protostar is drawing material from a surrounding disk of dust and gas that is roughly the size of Jupiter’s orbit. The developing gas giants (rings indicate debris remaining from their formation) sweep up infalling dust from the outer disk creating the open area; the gap is about the distance between Jupiter’s and Saturn’s orbits. Current theory holds that our own solar system formed from the collapse of a gaseous cloud called the solar nebula. Originally 2–3 times the mass of the Sun and 100 AU in diameter (1 AU is the Earth–Sun distance; Pluto’s orbital diameter is 80 AU), some disturbance like a nearby supernova pressed our nebula inward. At that point gravitational forces overcame the internal gas’ outward pressure, and the nebula began to collapse. If an ice skater pulls in her arms while spinning, her rate of spin increases; this is called conservation of angular momentum. So as our spinning solar nebula contracted due to gravitational collapse, it spun faster. Now gravity, angular momentum, internal gas pressure, and magnetic fields acted on our solar nebula; and in concert caused it to flatten into a spinning, planet-forming disk of dust and clumps of matter, with the largest clump in the center.

The author, his poetry and instruments

Virgo and Venus in "You and the Universe"