The man sending cameras to Mars

Original article published in Asahi Shimbun Globe+, available here (Japanese).

Ever looked up to the night sky on a clear night, and seen the shimmering, iridescent beauty of an aurora? These natural light displays are prized by photographers worldwide. Japanese scientist, Dr Ryuho Kataoka, has plans to take particularly unique aurora photos — by sending cameras to Mars.

Ryuho Kataoka is on a mission to shrink the cameras we use for studying auroras. To monitor space weather, we need lighter electronics that retain their powerful data collection functions.

© Jeffery Prine/OIST

Becoming an aurora expert

Today Kataoka is a renowned aurora and space weather expert, leading space physics research at the Okinawa Institute of Science and Technology (OIST). But it wasn’t until relatively late in his career that the scientist first saw an aurora with his own eyes. “I was trying to decide what to research when I was a third-year undergraduate student,” he says. “Although I’d only seen auroras on TV or in photographs, I decided to specialize in this field so that I might one day get the chance to see an aurora for myself.” He eventually saw his first aurora during a conference in Alaska, where it made him feel wondrously small, in his words, “like we are just tiny animals on a planet traveling through the vastness of space”.

Since then, Kataoka has spent over two decades researching auroras and related space weather phenomena, with the aims of understanding the physics of these light shows and improving the safety of air and space travel. 

Kataoka on a research expedition to Athabasca in central Canada. He has many collaborators around the globe who he works with to get detailed information about auroras and other space weather phenomena.

© Ryuho Kataoka

“If we can understand the scientific foundations of space weather and when events are likely to occur, we can design air and space travel around these predictions,” says Kataoka. “One of my first projects was building a tool to predict radiation risks for airplane passengers at different locations and altitudes based on space weather data. And I’m interested in how we can protect astronauts better too.”

What is an aurora?

Auroras appear at times of high-speed solar wind, when stars such as our Sun emit streams of high temperature charged particles. These interact with the Earth’s magnetic field, generating huge electric current, concentrating the electric current in polar regions where they collide with atmospheric gases such as oxygen and nitrogen. On collision, the gases are excited and light is emitted, forming the characteristic glowing auroras that Kataoka studies.

Beautiful auroras are seen on clear nights on the Earth. But what about Mars? Meet the scientist trying to capture better images of auroras on Mars.

© NASA

Auroras can be different colors depending on the gases present in the atmosphere. On Earth, oxygen is abundant, and causes green, or at higher altitude, red emissions. Nitrogen causes blue or purple light. Carbon dioxide also causes blueish light, of a slightly different color and wavelength.

“Auroras are an important visual indicator of solar activity,” highlights Kataoka. “Strong solar activity can affect health for those with higher exposure levels, like astronauts, and can also disrupt satellite communication, GPS technologies and power grids. That’s why it’s important to research space weather and build better predictions for solar events.” 

Kataoka and his colleagues use a variety of techniques to study and date such weather events, including reading the 800-year-old diaries of a Medieval Japanese poet who wrote about the auroras they saw. By dating solar events with historical literature and carbon-14 measurements, scientists can understand the trends and likely frequency of particular events and refine their space weather models. 

Dr Ryuho Kataoka is a space weather expert interested in building better cameras to study auroras. His work takes him to the far flung reaches of the globe — and his cameras may soon go beyond, all the way to Mars!

© Ryuho Kataoka

Understanding the Martian auroras

Even the keenest amateur photographer might struggle with Kataoka’s latest challenge—photographing auroras that are 140 million miles away.  

His team are part of a large, multi-institute project, funded by JAXA (the Japan Aerospace Exploration Agency) to design and build environmental sensors such as specialized imagers for use in space ahead of their future Mars missions. This may seem a long time away, but to design, program, build and thoroughly test all the devices is no small task. “We only get one shot at this,” says Kataoka. “I can’t exactly go and fix the camera if it breaks!” 

So, why study Mars auroras? Until recently, scientists didn’t think the Red Planet could host auroras, given its weak magnetosphere — the region of space around the planet where charged particles can interact with its magnetic field. But three different types of auroras are thought to be able to fleetingly form. Kataoka’s cameras will capture key data to help understand these interesting phenomena and improve space weather prediction.

Charged particles released by the sun and other stars can interact with planetary magnetic fields in areas known as ‘magnetospheres’. 

© NASA/CILab/Josh Masters

In order to do this, the cameras must be energy efficient, light enough and small enough to fit on the probes destined for the Martian surface. They’ll need to keep functioning within the extremely cold surface environment and be able to detect light emissions very different from Earth auroras, due to the compositional differences between the planets’ atmospheres. 

To be useful in space, cameras must be lightweight and energy efficient. Here we see some of Kataoka’s cameras, including the tiny prototype (bottom right, next to coin) which may be used on Mars. 

© Jeffery Prine/OIST

“Mars has a lot more CO₂ in the atmosphere, so we expect to see blue light emissions in this range,” notes Kataoka. He’s designed special filters to target these wavelengths and is also developing AI processing software to enable these tiny cameras to make decisions on-site.

How Citizen Science is shaping aurora research on Earth

Of course, not everyone is able to send cameras into space. But you can still play your part in aurora research. Here in Japan, Hokkaido is one of the best regions for seeing auroras. By taking your own photos of the night sky, you can act as citizen scientists and help researchers to understand these beautiful phenomena.

For many years, Kataoka has analyzed space weather data in real time, sharing on social media when he predicts good auroras might be seen.

“People started taking my predictions seriously,” he says. “One keen photographer even booked a same-day trip from Tokyo to Hokkaido based on my social posts!” 

As more and more people shared their aurora images online, Kataoka realized a wealth of useful data was amassing. In 2024, he created＃オーロラシチズン (#AuroraCitizen in English), a hashtag which racked up millions of views and over 1,000 aurora photos. He’s now got an online form to collect valuable information and photos from enthusiastic citizen scientists. By analyzing public contributions, Kataoka and colleagues have authored several scientific papers reporting unusual emission heights and other important aurora characteristics.  The papers acknowledge hundreds of citizen scientists who contributed photographs, listing their names in the acknowledgments section.

“I’m glad that there are so many people who see the beauty in auroras, and are interested in the scientific side too,” says Kataoka. “By joining together, we can get a much more thorough understanding of how our atmosphere and space work.”

Photo of Dr Ryuho Kataoka

© Jeffery Prine/OIST

Biography: Dr Ryuho Kataoka

After graduating from Tohoku University with a PhD in Science in 2004, Kataoka worked at many different institutes, including the National Institute of Information and Communications Technology, NASA's Goddard Space Flight Center, Nagoya University, RIKEN, the Institute of Science Tokyo and the National Institute of Polar Research. He now leads space physics research at the Okinawa Institute of Science and Technology. He has a passion for outreach, supporting many citizen science projects and has written several space weather-related books, such as his latest book “Scary Space: The Threat of Massive Solar Flares and Magnetic Storms”, published in June 2026. The book summarizes many of his activities, from space weather forecasting to literature surveying to his new Mars challenge. He also hosts two podcast channels "地球人ラジオ” and "OIST HUB RADIO." His X account has more than 42K followers.