Having covered the Solar System fairly thoroughly, I thought it would be good to move on to other topics. Today we talked about the fact that all the elements we know are formed in fusion processes within stars. The first generation of stars that appeared shortly after the Big Bang (that occurred nearly 14 billion years ago) were mostly composed of hydrogen. They were hyper giant stars, and quickly burned hydrogen into helium (and a trace of other elements). When they had consumed their fuel, they exploded as supernovae, seeding nebulae with the elements that would then form the next generation of stars, such as our Sun. Today we covered the concepts of 'element', 'Big Bang', and 'supernova'. Gwendolyn remembered a video we had watched in the first semester on the scale of stars with respect to more familiar objects such as our Moon, so we watched that again.