I chose the meteorite dataset for the map assignment.
For the map visualization, I used Stamen Maps and followed the demonstration given by Ingrid Burrington. An interesting thing happened on account of me not knowing that the latitudes and longitudes were interchanged in the dataset. This left me baffled as to why the overwhelming majority of meteorite strikes were concentrated in Europe and Africa. I initially attributed it to a corrupt dataset. It was only during the second visualization that I realized my mistake. Seeing the points fit perfectly inside continents was immensely satisfying.
For the non-map visualization, I used D3 to plot the total mass of meteorite hits as a function of year between 1600 and 2000. I visualized total mass as 2-D circles with varying radii. I had initially mapped mass to radius, which led to an exponential increase in circle size. In the screenshot below, I have corrected the circle radius to vary by cube root of total mass.