James O'Donoghue went viral for the first time in December 2018.

He was a planetary scientist for NASA at the time, but the federal government had temporarily shut down due to budget disputes in Congress. He'd been told not to work or even check his email. So with extra time on his hands, he took to Photoshop.

O'Donoghue and his NASA colleagues had just measured the material raining onto Saturn from its rings, and found that the rings will slowly fall away over 100 million years. He realized that people would probably wonder what that will look like.

So a few days before their study's publication, O'Donoghue slapped an expanding black circle onto an image of Saturn and faded most of its rings away. The New York Times featured his animation with the news of the study.

saturn rings disappearing gif
O'Donoghue's impression of how Saturn may look in the next 100 million years. The innermost rings disappear as they rain onto the planet.
NASA/Cassini/James O'Donoghue

Then, as he continued to roam the Internet while waiting for government work to resume, O'Donoghue realized that he couldn't find any videos comparing each planet's spin side by side. So he made one.

He pulled together images of all the planets, tilted them to the correct degree, and made them spin at their real-life speeds. He threw numbers next to them for good measure.

The video took off.

"It was viewed by 1.6 million [people] in a couple of days. As someone with 450 followers, I thought that was a bit ridiculous," O'Donoghue told Insider.

But he realized that it had taken about 16 hours to make the video, which means he'd reached roughly 100,000 people for each hour of work.

"I thought, 'This is actually kind of efficient' — an efficient way of doing outreach to people," he said. "If you're from a rural area like myself, that's kind of important. I didn't have any exposure to any scientists where I'm from. You'd have to go very far away to reach one."

O'Donoghue grew up in the English town of Shrewsbury, then later among the hills and farms of Newton, Wales. He'd never thought of astronomy as a career option until he left for university. 

Since the planets video, O'Donoghue has almost always had another idea for an animation bouncing around in his head. He has now created more than 80 such animations for his Youtube channel.

The effort earned him the Europlanet Society's Prize for Public Engagement last month.

James O’Donoghue selfie in front of nasa symbol
James O’Donoghue at NASA.
James O’Donoghue

"Among the talented and motivated science communication projects nominated this year, James O'Donoghue's brilliant animations stood out," Dr. Federica Duras, who chaired the award jury, said in a press release. "In their simplicity they are a masterclass in outreach and communication, and the fact that they do not rely on language and translation means that they are perfectly inclusive, easily adaptable and usable all over the world."

"A lot of this is just play," O'Donoghue, who now works at the Japan Aerospace Exploration Agency (JAXA), told Insider. "I kind of just go where I enjoy with it."

Here are some of his best videos.

After his early successes, O'Donoghue pivoted to illustrating the speed of light

This series of videos shows a particle of light (a photon) traveling across different distances in space. It zips around Earth faster than you can blink, and ping-pongs between Earth and the moon every 1.255 seconds.

But the distance between planets is so large that it takes a photon several minutes to cross. That's why space agencies like NASA will always have a delay in communicating with rovers on Mars — even if they develop the ability to send messages at light speed.

Another video shows how the moon has retreated over 4.5 billion years

About 4.5 billion years ago, a Mars-sized object (or perhaps a series of many smaller objects) crashed into Earth, sending bits of our planet's crust into space. They fell into Earth's orbit and eventually coalesced, forming our moon. That newborn moon — a ball of molten rock with a magma ocean — was nearly 16 times closer to Earth than it is today.

As it cooled, the moon backed away, retreating thousands of miles.

O'Donoghue's sequence starts with the moon's current position and follows it back in time to its birth, tracking its distance from Earth, apparent size relative to our planet, and the speed of its movement.

Some videos debunk myths, like the dark side of the moon

Although there is a side of the moon that we never see from Earth, it's not dark all the time.

"Remember not to say 'dark side of the moon' when referring to the 'far side of the moon,'" O'Donoghue said on Twitter. "This graphic shows the dark side is always in motion."

The video shows how sunlight falls across the moon as it orbits Earth. In one orbit of about 29.5 days, all sides of the moon get bathed in sunlight at some point.

Others demonstrate shocking facts of physics — like the true center of the solar system

Hint: It's not really the sun.

"Instead, everything orbits the solar system center of mass," O'Donoghue explained on Twitter. "Even the sun."

That center of mass, called the barycenter, is the point of an object at which it can be balanced perfectly, with all its mass distributed evenly on all sides. In our solar system, that point rarely lines up with the center of the sun.

His animation shows how the sun, Saturn, and Jupiter play tug-of-war around the barycenter, pulling our star in looping mini-orbits.

Earth and the moon have their own barycenter, too

That point is about 3,000 miles from our planet's center, just below its surface.

By the way, Earth has two types of day

The sidereal day happens each time Earth completes a 360-degree rotation. That takes 23 hours and 56 minutes.

But because Earth is constantly moving along its orbit around the sun, a different point on the planet faces the sun directly at the end of that 360-degree spin. For the sun to reach the exact same position in the sky, Earth has to rotate 1 degree further, which takes another four minutes to make a 24-hour spin.

The solar day — the one humans count in the calendar — happens when Earth spins that extra degree, and the sun is at the same point in the sky as it was 24 hours ago.

Because we go by solar days in our calendars, we count 365 days in a year. But Earth actually completes a full rotation (a sidereal day) 366 times per year.

A more recent video shows how fast (or slow) a ball would drop on each planet

For this video, O'Donoghue collaborated with Rami Mandow, who founded the website Space Australia.

The speed of the ball's fall depends on the planet's mass — a more massive planet has a stronger gravitational force — and its density. The closer the ball is to a planet's center of mass, the stronger the gravitational force.

"I really like how this one came out," O'Donoghue said.

Many of his animations compare the planets

This animation also shows how fast each planet spins and how much they're tilted on their axes.

He's also compared planets by putting them all on one globe

This video shows how quickly the planets spin relative to one another. Jupiter, for example, rotates 2.4 times faster than Earth.

His adaptation of a NASA animation shows the oceans draining away

This remake of a 2008 NASA video shows what it would look like if Earth's water drained away, revealing the hidden three-fifths of the planet's surface.

"This animation reveals that the ocean floor is just as variable and interesting in its geology as the continents," O'Donoghue said.

O'Donoghue even circled back to his main research subject: Saturn

It may not be obvious in photos, but the ice and rock chunks that make up Saturn's rings circle at rates nearly 70 times the speed of sound. But each ring moves at its own specific pace. The animation above shows how it all moves.

"In a way, the ring system is like a mini solar system," O'Donoghue said. "Objects close to Saturn orbit faster, otherwise they would fall in, while objects far away can afford to go slower. This is the same for planets."

A picture of a switch and lightbulb
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