A Topographic Map of the Moon
August 19 2019 · Link to the Open-Source Code
My next two maps in the Atlas of Space series show the topography and geology of the Moon. These were some of my favorite datasets in the project - the Moon is our closest celestial neighbor, and we know a lot more about the Moon than about our neighboring planets. The Apollo missions even returned several hundred kilograms of lunar rock to the Earth for detailed analysis.
The moon is tidally locked to the Earth, which means that it completes one rotation around its axis in exactly the same time that it takes to circle around the Earth. Because of this, the far side of the moon is never visible from the Earth’s surface. This topographic map shows the near side of the moon in the large central map, as well as the North pole, South pole, far side, and interior in the four surrounding maps.
People have been fascinated by the moon for thousands of years, and lunar events like the full moon or an eclipse are tied to ancient calendars, myths, and celebrations. The lunar cycle can even be seen today in the pattern of Google searches for the word “moon,” which peaks predictably during every full moon.
1: Data layers used to design this map. 2: Google search frequency for the word “moon” in the United States (data from Moon phase dates and Google Trends). Each yellow line shows one lunar cycle in 2018, normalized to the highest and lowest value within each lunar cycle. The turquoise line shows the overall mean.
- Data: Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU). © 2019 Working Group for Planetary System Nomenclature (WGPSN). Earth's Moon In Depth. © 2019 NASA Science Solar System Exploration. LRO LOLA Elevation Model 118m (LDEM GDR). © 2018 NASA PDS and Derived Products Annex. LOLA Science Team. Reference texts: Astronomy, Andrew Fraknoi, David Morrison, Sidney C. Wolff et al. © 2016 OpenStax. Fonts: The labels on this map are typeset in Moon by Jack Harvatt. The title font is RedFlower by Type & Studio. Advice: Thank you to Oliver Fraser, Henrik Hargitai, Chloe Pursey, and Leah Willey for their helpful advice in making this map.
An Animated Sketch of Jupiter
August 2 2019 · Link to the Open-Source Code
This week’s map is just for fun! The animated GIF illustrates the storms on Jupiter, but it’s an artistic drawing rather than an accurate representation of the clouds in real time. The majority of the work was done in Photoshop, based on images published from the Cassini spacecraft in 2000 and 2006.
At first I wasn’t planning to map Jupiter, because the surface is constantly changing. We also have much less information about the gas giants compared to the rocky planets closer to Earth. But then I found this awesome video of Jupiter’s clouds, and I decided to edit the film into a repeating cycle.
To make a more detailed design, l I used Cassini’s high-resolution Jupiter map as the background, and placed the lower resolution video on top as a semi-transparent layer. Cassini’s video doesn’t include any data for the North or South poles, so the very top and bottom of this map aren’t animated. You can probably see the discontinuity at about the second bolded latitude line (though it’s not too noticeable because of the low wind speed near the poles).
The high-resolution version of Cassini’s Jupiter map (1) is much more detailed than the video version (2). I combined both of them together to get both detail and animation into the design. The original video doesn’t actually loop, but you can gradually fade the frames at the end of the movie to give the illusion of continuous flow. I also removed the occasional shadowy blotches cast by Jupiter’s moons, and edited the colors and contrast in the video to match the background image.
Although I labeled some of Jupiter’s cloud layers, the storms are constantly shifting and individual bands can move or change color over time. Even the Great Red Spot, a huge storm big enough to swallow the Earth whole, is gradually shrinking and could disappear within our lifetime.
- Data: PIA07783. Cassini's Best Maps of Jupiter (North Polar Map). © 2006 NASA, JPL, and the Space Science Institute. PIA07784. Cassini's Best Maps of Jupiter (South Polar Map). © 2006 NASA, JPL, and the Space Science Institute. PIA02863. Planetwide Color Movie. © 2000 NASA, JPL, and the University of Arizona. PIA07782. Cassini's Best Maps of Jupiter (Cylindrical Map). © 2006 NASA, JPL, and the Space Science Institute. Reference texts: Astronomy, Andrew Fraknoi, David Morrison, Sidney C. Wolff et al. © 2016 OpenStax. Fonts: The labels on this map are typeset in Moon by Jack Harvatt. The title font is RedFlower by Type & Studio. Advice: Thank you to Chloe Pursey and Leah Willey for their helpful advice in making this map.
Constellations from Around the World
July 29 2019 · Link to the Open-Source Code
Two weeks ago I shared a map of all the stars you can see from Earth, alongside the Western constellations. But the Western constellations are only one of many patterns of stars invented by cultures around the world. This week’s map illustrates the animals, people, and objects imagined in the sky by more than 30 different civilizations.
To make this map I used data from Stellarium, an open-source planetarium software that includes constellations from ancient Dakota, Hawaiian, and Mongolian cultures, among many others. Some of my favorite constellations were the Stars of Water, Rabbit Tracks, and the Hippopotamus, and I also really liked the star names The Oath Star, Lady of Life, and The Hand of the Mouse.
The stars around the Western constellation Orion are one of the busiest places on the map. Some of the individual cultures are highlighted here, including the Chinese constellations in red, ancient Egyptian in turquoise, and Arabic in green. I really liked that each of these cultures included the triple stars in “Orion’s belt”, but still interpreted the star patterns in a completely different design.
The color scheme for this map was inspired by antique roadmaps, like this map of Nebraska from 1898. But this is the only map in the series without a dark background, and I wasn’t quite convinced that a lighter background could work for a star map. I even made two different versions before finally deciding to stick with the original color scheme.
I originally wanted to label the constellations in each culture’s language, but the translations for Stellarium are an ongoing process (that you can help out with, by the way!). I did the best I could by including Chinese labels, which were already fully translated in Stellarium, and by adding phonetic ひらがな labels for Japanese moon signs (I speak Japanese).
This map was definitely one of my favorite designs. At first I was worried that with so many constellation lines, the map would look like a tangled ball of yarn. So I was pleasantly surprised to see that the “ball of yarn” still had a clear pattern - the brightest stars were shared across almost every single culture across the world. I’ll admit that the final map is probably a little too busy to clearly see the individual constellations. But in the end I think the charm of this dataset is seeing the crisscrossing connections shared across the globe, even if the lines are a little entangled.
- Data: Stellarium. © 2019 version 0.19.0. HYG Database version 3. © 2019 David Nash. Reference texts: Astronomy, Andrew Fraknoi, David Morrison, Sidney C. Wolff et al. © 2016 OpenStax. Fonts: The labels on this map are typeset in Moon by Jack Harvatt. The title font is RedFlower by Type & Studio. Advice: Thank you to Nadieh Bremer, Oliver Fraser, Chloe Pursey, and Leah Willey for their helpful advice in making this map.