Joshua Stevens

October 21, 2026

Eikon: A Library of The Saints

Maps are one of my core passions. But I also have a deep interest in art, history, and the church. In my spare time I’ve been tinkering with an idea to build an interactive, searchable library of iconography. Some recent downtime provided just the right opportunity to bring it to life.

October 17, 2026

Still Bivariate, Still Curious

Eleven years ago I wrote a how-to guide for bivariate choropleth maps, prompted by a quip I overheard at NACIS: “I’m not bivariate, but I am curious.” Back then, making bivariate maps meant blending color schemes in graphics programs, hand-tuning the corner where both variables run high, and stitching two classifications together into a single attribute your software could understand. It worked in any tool, but it took some patience. A lot has changed since then.

September 23, 2026

Introducing Phosphor

I am proud to release Phosphor, a new tool to make color for data visualization even easier.

September 21, 2026

Formatting Gratitude

“Don’t take the job,” he said. Almost thirteen years have passed since my friend and mentor shared these words. He was the only dissenting voice among half a dozen professionals and friends whose opinions I sought. And it’s not those four words, but the rationale behind them, that has stuck with me the most. Flashback to the brisk autumn of 2014. I had earned PhD candidacy the year before, passed comprehensive exams the previous semester, and my son was entering his sixth month of life on Earth. It was an exciting time—and it was about to get a lot more exciting.

March 7, 2022

Behind the Scenes of the Earth Observatory

Since 1999 NASA’s Earth Observatory has produced more than 12,000 data visualizations, images, and maps. To do so, we have adopted an approach that enables us to be both consumers and producers of science. In other words: we use science to inform how we communicate science.

March 7, 2022

Mapping Ukraine's Refugees

Disasters are the great catalysts of cartography. There is no stronger impetus for new maps than earthquakes, landslides, floods… and wars. With new maps come new desires. The field of cartography has come a long way, and both its practitioners and students have learned a great deal. Myriad data sources are within an ever-closer grasp, and we’ve learned to approach each with more care, more diligence, and more responsibility.

January 4, 2021

2020 Top 10

The NASA Earth Observatory publishes a new image-driven article every day. This torrent of graphics is enhanced by coverage of breaking news, natural hazards, and periodic, deep-diving features. As a result, our team easily publishes more than 500 visuals each year. Choosing the ten best from such list is no small task. And it inevitably leaves out numerous pieces that, to be honest, pains me to exclude. Nonetheless, ten it shall be.

April 2, 2020

The Red Planet

I am extremely pleased to release a new poster showcasing the topographic relief of Mars. My days are usually filled with Earth. Satellite images, maps, data analysis… all originating from, or looking at, our blue planet. The third rock from the Sun. Sometime last year I decided to figuratively leave Earth and see what’s going on with our skyward neighbor.

January 23, 2020

Pinewood Nerdy

I was not sure what to expect when my son wanted to sign up for cub scouts. But I knew, at some point, Pinewood Derby would come into the picture. The moment came. He built a car. He raced it. And it was just as awesome as we had hoped. With so much creativity and hands-on crafting, followed by actual racing, it’s a tough experience to top. Then I saw the data being recorded by the digital track. Now it was my turn to have some fun.

April 1, 2019

Tutorial: Turning on The Lights

The most familiar views of Earth from space feature a blue-green planet lit by the Sun. But in the darkness of night when the Moon, city lights, fires, or aurorae illuminate Earth, some satellites continue to gather images of light. And they are fantastic! So how does such imagery come to be? Let’s take a look!

Notes on maps & visual storytelling