Colby College Astronomy Blog

The Formation of the Solar System: Collapse of the Solar Nebula

“For a star to be born, there is one thing that must happen; a gaseous nebula must collapse. So collapse. Crumble. This is not your destruction. This is your birth.”

-N.T.

I have been sitting with the quote above for the past few days. Seeing as this is a blog post I thought it would be fitting to write about my topic, the collapsing of the solar nebula, over a short timespan. The quote inspired me to make use of the colored pencils I impulsively bought over the weekend.

Unsurprisingly, as I continued my research I continued to sketch. Some doodles translate concepts regarding the formation of the solar system well; others are a product of procrastination and therefore make less sense. Regardless, I thought I’d share some of my illustrations in order to help readers obtain a more candid view of my experience researching this topic.

I decided to stick with the balloon theme. The poor, unsuspecting girl lost her balloon (which represents the large, diffuse cloud of gas and dust our solar system derived from) because it began to condense. This cloud was composed of 98% Hydrogen and Helium gas, and the condensing process was most likely due to waves that were sent toward it by a nearby star exploding (a supernova), thus squeezing the gas and dust together. The solar nebula was a product of the gravitational pull between this gas and dust, consequently causing the cloud to begin spinning. The direction of the cloud’s spin can be explained by the collision of particles  -- eventually, the cloud generated a preferred direction in the spinning increased in speed due to angular momentum. Once the general direction was established, the gravitational pull and increased spinning speed resulted in the solar nebula’s transformation from an oval shape to an elongated disk formation.

We've intrigued our girl, now. Following the formation of the disk, material began to accumulate in the disk’s center as the disk grew thinner and hydrogen atoms fused into helium. Some clumps that formed eventually matured into planets or moons depending on how close they were to the disk’s center. Due to the heat from the nuclear fusion, only rocks and metals could stand the high temperatures (like Earth!). Likewise, ices settled into regions on the outer edges of the disk (like Jupiter!) because the center was too hot for ices to condense.

Girl's eye reflects cooler (and redder), outer edges of the disk.

Girl's eye reflects hotter (and bluer) disk center, where nuclear fusion occurs.

The more the cloud condensed, the higher the temperature grew. The nuclear fusion eventually caused the disk’s center to grow so hot that it gave birth to our sun!

Well, it didn’t give birth exactly, but you know what I mean.

Finally, the formation of the star precipitated a stellar wind that blew the gas and dust of our solar system outward.

References:

http://spaceplace.nasa.gov/solar-system-formation/en/

http://www.windows2universe.org/our_solar_system/formation.html