|Evidence suggests that the birth of the Solar System was triggered by a supernova blast that destabilized a nearby molecular cloud and caused it to collapse under its own gravity. This compacted cloud made our Solar System (more details later).
Molecular clouds are vast clouds cool enough for molecules to be stable. They consist of gas, molecular compounds, and dust. When you look up at the night sky on a starry night, such clouds are certainly not obvious. Are molecular clouds--the raw stuff of stars and planets--common, or did astronomers just make this stuff up to make a nice story?
By the end of this web page, you should be able to spot molecular clouds in telescope images. And you will know that, like some people, the Universe is impressively dirty and gassy.