https://docs.google.com/spreadsheets/d/1rpwoEOKi3jEby6ul_56ywvUo_H3aVks5xaSsXgzFcM4/edit?usp=sharing
https://docs.google.com/spreadsheets/d/1rpwoEOKi3jEby6ul_56ywvUo_H3aVks5xaSsXgzFcM4/edit?usp=sharing
http://www.msn.com/en-us/lifestyle/smart-living/33-of-the-most-amazing-science-breakthroughs-in-history/ss-AAk0M3y?li=BBnb7Kz&ocid=ASUDHP#image=1
http://www.msn.com/en-us/video/wonder/scientists-really-want-to-smash-a-spacecraft-into-an-asteroid/vi-AAkohip?ocid=ASUDHP
http://www.space.com/34515-supermoon-guide.html
http://chem.libretexts.org/Core/Analytical_Chemistry/Quantifying_Nature/Density_and_Percent_Compositions
https://www.sciencenews.org/article/units-measure-are-getting-fundamental-upgrade