This gif of a bumpy, rotating, potato-like Earth is weirdly ubiquitous online:
It resurfaces every few months, paired with the explanation that the image is demonstrating what the Earth would look like without water. It will show up on a message board one day, then a few months later on a random website. It's been posted on Reddit and Imgur, included in a Buzzfeed listicle, and it popped up again two days ago, gaining more than 100 retweets. Nearly every time it appears, it's alongside the label: what the Earth would look like without water.
But as one or two rational people point out every time the gif makes the rounds: that is not what the Earth would look like without water.
The gif is actually illustrating the variation in gravity around the globe. There are very slight differences in gravity across the Earth, and those variations have been fastidiously measured by NASA satellites GRACE and CHAMP. In 2005, those measurements were used to create a visual representation of the Earth's gravity landscape dubbed "the Potsdam Potato" (because the team that analyzed the data was from a lab in Potsdam, Germany and, well, potato).
"High areas on this map, colored red, indicate areas where gravity is slightly stronger than usual, while in blue areas gravity is slightly weaker," reads a description of the graphic from NASA. Because the variations in gravity are subtle, they're exaggerated in the image so that you can more easily see the difference (read: the Earth isn't really that wonky).
But neither NASA nor the team at Potsdam made the gif (they only released static 3D images of the maps). In fact, the team at Potsdam were a bit confused when I sent them the image, telling me it was indeed their potato, but with slightly different colors.
That's because it was actually made by Ales Bezdek, a researcher at the Astronomical Institute at the Academy of Sciences of the Czech Republic. A couple of years ago, Bezdek shared some free coding for MATLAB, a programming language used for data visualization, to show how it could be used to create 3D models of the Earth and celestial bodies. One of his examples was, you guessed it, an animated image of the Earth's gravity fields, and included a script so you could use the Potsdam data and MATLAB to make a gif of your own.
Bezdek also made a few other cool examples, like the topography of Mars with some psychedelic colors:
As for the "Earth without water" myth that's been attached to this gif, I couldn't locate a convincing origin. But if you're curious, I did find out what the Earth would look like without water (via NASA, a much more reputable source than the popular net). Turns out, unscientifically speaking, it would look pretty much the same: