A week ago on Sunday I suddenly realised that I had nothing prepared for this week’s MakeoverMonday. With a busy week of celebrating my birthday among boxes and half constructed furniture as I am slowly settling into my new place in Nuremberg, plus a busy training schedule ahead of Nationals, it was time to get the topic and data organised.
A quick google search for 21 August brought up the impending solar eclipse and a couple of minutes later I had downloaded a dataset of 5000 years of solar eclipses thanks to NASA who compiled it reaching from 2000BC to 3000AD. Cool!!! I then roped in Simona Loffredo to give me a hand with tidying up the data in Alteryx (Thanks, Simona!) and after a quick play in Tableau, the data was ready.
I wasn’t, so after an IKEA-filled day and a restful sleep in my new bed, I was finally ready to release the data this morning as I wanted to give everyone a bit more time to create their vizzes with the solar eclipse happening tomorrow. To be honest, I am hoping to see some very informative and educational vizzes that can be shared with the wider dataviz community.
So, let’s get into it. This week’s viz is a map of solar eclipses from 2001 – 2020 AD
What works well:
- everyone likes maps, so the viz draws attention easily and people understand the global context of what is displayed
- the interactivity is great, with hover actions displaying additional content in a tooltip and highlighting the path of the eclipse in a darker shade
- the information provided above the map is excellent to guide the audience in how to read the map and has additional information linked for those who want to find out more
- because this viz is overlayed on google maps, you can change to a satellite version which also looks very cool
- the footnote provides additional information which is relevant to the timings shown in the viz
What could be improved:
- the viz is very busy due to the boxes with the date information. Maybe a circle or other symbol per eclipse would suffice and the date information could all be contained in the tooltip
- against the coloured map the blue and red lines and boxes are very bright and ‘intense’. Some subtler hues may work better
- with the map being repeated on the side it becomes confusing as to why some of the areas don’t display the same eclipses on the maps at the edges as they do on the map in the middle, i.e. why is the ‘repeated’ South America on the right hand side not also covered in marks?
- while the title is short and succinct, it doesn’t excite me to explore te data further as it basically suggests a listing of all the eclipse events over the stated time period. So what?
What I did:
- first, I spent quite a bit of time exploring the data, going through animations by centuries, visualizing all the events in a single chart. I also played around with bar charts and others but didn’t really find my story until it happened by accident
- keen to understand duration further, I plotted it against latitude and bingo, here was my story: duration tends to be shorter at the poles and longer at the equator for full solar eclipses
- regarding my design I opted to remove the y-axis in favor of reference lines for the three key points: north pole, equator and south pole
- given that the pattern for duration is like a Rorschach blot with the Equator in the middle and the poles being almost mirror images on either side, I wanted a colour scale that reflected those similarities, so I created a calculated field using the absolute values of Latitude (ABS([Latitude]) and dragging this field on colour. I felt very smug and clever with this solution
- add to that a couple of annotations ot further clarify the chart and I was done
Click on the image for the interactive version