Space & Physics

In search for red aurorae in ancient Japan

Ryuho Kataoka, a Japanese auroral scientist, played a seminal role in searching for evidence of super-geomagnetic storms in the past using historical methods

Published

1 year ago

February 5, 2024

Karthik Vinod

Professor Ryuho Kataoka in his office at NIPR, with the fan-shaped painting behind him, Picture courtesy: RK Works

Aurorae seen on Earth are the end of a complex process that begins with a violent, dynamic process deep within the sun’s interior.

However, studying the depths of the sun is no easy task, even for scientists. The best they can do is to observe the surface using space-based telescopes. One problem that scientists are attempting to solve is how a super-geomagnetic storm on Earth comes to being. These geomagnetic storms find their roots in sunspots, that are acne-like depressions on the sun’s surface. As the sun approaches the peak of its 11-year solar cycle, these sunspots, numbering in the hundreds, occasionally release all that stored magnetic energy into deep space, in the form of coronal mass ejections (CMEs) (which are hot wisps of gas superheated to thousands of degrees).

If the earth lies in the path of an oncoming CME, the energy release from their resultant magnetic field alignment can cause intense geomagnetic storms and aurorae on Earth.

This phenomenon, which is astrophysical and also electromagnetic in nature, can have serious repercussions for our modern technological society.

Super-geomagnetic storms, a particularly worse form of geomagnetic storm, can induce power surges in our infrastructure, causing power outages that can plunge the world into darkness, and can cause irreversible damages to our infrastructure. The last recorded super-geomagnetic storm event occurred more than 150 years ago. Known as the Carrington event, the storm destroyed telegraph lines across North America and Europe in 1859. The risk for a Carrington-class event to happen again was estimated to be 1 in 500-years, which is quite low, but based on limited data. Ramifications are extremely dangerous if it were to ever happen.

However, in the past decade, it was learnt that such super-geomagnetic storms are much more common than scientists had figured. To top it all, it wasn’t just science, but it was a valuable contribution by art – specifically ancient Japanese and Chinese historical records that shaped our modern understanding of super-geomagnetic storms.

Ryuho Kataoka, a Japanese space physicist, played a seminal role in searching for evidence of super-geomagnetic storms in the past using historical methods. He is presently an associate professor in physics, holding positions at Japan’s National Institute of Polar Research, and The Graduate University for Advanced Studies.

“There is no modern digital dataset to identify extreme space weather events, particularly super-geomagnetic storms,” said Professor Kataoka. “If you have good enough data, we can input them into supercomputers to do physics-based simulation.”

However, sunspot records go until the late 18th century when sunspots were actively being cataloged. In an effort to fill the data gap, Professor Kataoka decided to be at the helm of a very new but promising interdisciplinary field combining the arts with space physics. “The data is limited by at least 50 years,” said Professor Kataoka. “So we decided to search for these red vapor events in Japanese history, and see the occurrence patterns … and if we are lucky enough, we can see detailed features in these lights, pictures or drawings.” Until the summer of 2015, Ryuho Kataoka wasn’t aware of how vast ancient Japanese and Chinese history records really were.

“There is no modern digital dataset to identify extreme space weather events, particularly super-geomagnetic storms,” said Professor Kataoka.

In the past 7 years, he’s researched a very specific red aurora, in documents extending to more than 1400 years. “Usually, auroras are known for their green colors – but during the geomagnetic storm, the situation is very different,” he said. “Red is of course unusual, but we can only see red during a powerful geomagnetic storm, especially in lower latitudes. From a scientific perspective, it’s a very reasonable way to search for red signs in historical documents.”

A vast part of these historical red aurora studies that Professor Kataoka researched came from literature explored in the last decade by the AURORA-4D collaboration. “The project title included “4D”, because we wanted to access records dating back 400 years back during the Edo period,” said Professor Kataoka.

“From the paintings, we can identify the latitude of the aurora, and calculate the magnitude or amplitude of the geomagnetic storm.” Clearly, paintings in the Edo period influenced Professor Kataoka’s line of research, for a copy of the fan-shaped red aurora painting from the manuscript Seikai (which translates to ‘stars’) hangs on the window behind his office desk at the National Institute of Polar Research.

The painting fascinated Professor Kataoka, since it depicted an aurora that originated during a super-geomagnetic storm over Kyoto in 1770. However, the painting did surprise him at first, since he wondered whether the radial patterns in the painting were real, or a mere artistic touch to make it look fierier. “That painting was special because this was the most detailed painting preserved in Japan,” remarked Professor Kataoka. “I took two years to study this, thinking this appearance was silly as an aurorae scientist. But when I calculated the field pattern from Kyoto towards the North, it was actually correct!”

Fan-shaped red aurora painting from the ‘Seikai’, dated 17th September, 1770; Picture Courtesy: Matsusaka City, Mie Prefecture.

The possibility to examine and verify historical accounts using science is also a useful incentive for scholars of Japanese literature and scientists partaking in the research.

“This is important because, if we scientists look at the real National Treasure with our eyes, we really know these sightings recorded were real,” said Professor Kataoka. “The internet is really bad for a survey because it can easily be very fake,” he said laughing. It’s not just the nature in which science was used to examine art – to examine Japanese “national treasures” that is undoubtedly appealing, but historical accounts themselves have contributed to scientific research directly.

“From our studies, we can say that the Carrington class events are more frequent than we previously expected,” said Professor Kataoka. There was a sense of pride in him as he said this. “This Carrington event is not a 1 in 200-year event, but as frequent as 1 in 100 years.” Given how electricity is the lifeblood of the 21st century, these heightened odds do ingrain a rather dystopian society in the future, that is ravaged by a super-geomagnetic storm.

Professor Kataoka’s work has found attention within the space physics community. Jonathon Eastwood, Professor of Physics at Imperial College London said to EdPublica, “The idea to use historical information and art like this is very inventive because these events are so rare and so don’t exist as information in the standard scientific record.”

There’s no physical harm from a geomagnetic storm, but the threat to global power supply and electronics is being increasingly recognized by world governments. The UK, for instance, identified “space weather” as a natural hazard in its 2011 National Risk Register. In the years that followed, the government set up a space weather division in the Met Office, the UK’s foremost weather forecasting authority, to monitor and track occurrences of these coronal mass ejections. However, these forecasts, which often supplement American predictions – namely the National Oceanic and Atmospheric Administration (NOAA) – have failed to specify previously where a magnetic storm could brew on Earth, or predict whether a coronal mass ejection would ever actually strike the Earth.

The former occurred during the evacuation process for Hurricane Irma in 2017, when amateur radio ham operators experienced the effects of a radio blackout when a magnetic storm affected the communications network across the Caribbean. The latter occurred on another occasion when a rocket launch for SpaceX’s Starlink communication satellites was disrupted by a mild geomagnetic storm, costing SpaceX a loss of over $40 million.

Professor Kataoka said he wishes space physicists from other countries participate in similar interdisciplinary collaborations to explore their native culture’s historical records for red aurora sightings. He said the greatest limitation of the AURORA-4D collaboration was the lack of historical records from other parts of the world. China apparently boasts a history of aurora records longer than Japan, with a history lasting before Christ himself. “Being Japanese, I’m not familiar with British, Finnish or Vietnamese cultures,” said Professor Kataoka. “But every country has literature researchers and scientists who can easily collaborate and perform interdisciplinary research.” And by doing so, it’s not just science which benefits from it, but so is ancient art whose beauty and relevance gains longevity.

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Karthik Vinod

Karthik Vinod is a freelance science writer and journalist from Kochi, India.

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Dr. Nikku Madhusudhan Brings Us Closer to Finding Life Beyond Earth

Dr. Madhusudhan, a leading Indian-British astrophysicist at the University of Cambridge, has long been on the frontlines of the search for extraterrestrial life

Published

10 seconds ago

April 18, 2025

Joe Jacob

Somewhere in the vast, cold dark of the cosmos, a planet orbits a distant star. It’s not a place you’d expect to find life—but if Dr. Nikku Madhusudhan is right, that assumption may soon be history.

Dr. Madhusudhan, a leading Indian-British astrophysicist at the University of Cambridge, has long been on the frontlines of the search for extraterrestrial life or what we call the alien life. This month, his team made headlines around the world after revealing what could be the strongest evidence yet of life beyond Earth—on a distant exoplanet known as K2-18b.

Using data from NASA’s James Webb Space Telescope, Madhusudhan and his collaborators detected atmospheric signatures of molecules commonly associated with biological processes on Earth—specifically, gases produced by marine phytoplankton and certain bacteria. Their analysis suggests a staggering 99.7% probability that these molecules could be linked to living organisms.

“This marked the first detection of carbon-bearing molecules in the atmosphere of an exoplanet located within the habitable zone,” the University of Cambridge said in a press statement. “The findings align with theoretical models of a ‘Hycean’ planet — a potentially habitable, ocean-covered world enveloped by a hydrogen-rich atmosphere.”

Born in India, Dr. Madhusudhan began his journey in science with an engineering degree from IIT (BHU) Varanasi

In addition, a fainter signal suggested there could be other unexplained processes occurring on K2-18b. “We didn’t know for sure whether the signal we saw last time was due to DMS, but just the hint of it was exciting enough for us to have another look with JWST using a different instrument,” said Professor Nikku Madhusudhan in a news report released by the University of Cambridge.

The man behind the mission

Born in India, Dr. Madhusudhan began his journey in science with an engineering degree from IIT (BHU) Varanasi. But it was during his time at the Massachusetts Institute of Technology (MIT), under the mentorship of exoplanet pioneer Prof. Sara Seager, that he found his calling. His doctoral work—developing methods to retrieve data from exoplanet atmospheres—would go on to form the backbone of much of today’s planetary climate modeling.

Now a professor at the University of Cambridge’s Institute of Astronomy, Madhusudhan leads research that straddles the line between science fiction and frontier science.

A Universe of Firsts

Over the years, his work has broken new ground in our understanding of alien worlds. He was among the first to suggest the concept of “Hycean planets”—oceans of liquid water beneath hydrogen-rich atmospheres, conditions which may be ideal for life. He also led the detection of titanium oxide in the atmosphere of WASP-19b and pioneered studies of K2-18b, the same exoplanet now back in the spotlight.

His team’s recent findings on K2-18b may be the closest humanity has ever come to detecting life elsewhere in the universe.

Accolades and impact

Madhusudhan’s contributions have earned him global recognition. He received the prestigious IUPAP Young Scientist Medal in 2016 and the MERAC Prize in Theoretical Astrophysics in 2019. In 2014, the Astronomical Society of India awarded him the Vainu Bappu Gold Medal for outstanding contributions to astrophysics by a scientist under 35.

But for Madhusudhan, the real reward lies in the questions that remain unanswered.

Looking ahead

Madhusudhan cautions that, while the findings are promising, more data is needed before drawing conclusions about the presence of life on another planet. He remains cautiously optimistic but notes that the observations on K2-18b could also be explained by previously unknown chemical processes. Together with his colleagues, he plans to pursue further theoretical and experimental studies to investigate whether compounds like DMS and DMDS could be produced through non-biological means at the levels currently detected.

Beyond the lab, Madhusudhan remains dedicated to mentoring students and advancing scientific outreach. He’s a firm believer that the next big discovery might come from a student inspired by the stars, just as he once was.

As scientists prepare for the next wave of data and the world watches closely, one thing is clear: thanks to minds like Dr. Nikku Madhusudhan’s, the search for life beyond Earth is no longer a distant dream—it’s a scientific reality within reach.

Space & Physics

Did JWST detect “signs of life” in an alien planet?

The presence of a commonly occurring organic compound dimethyl sulfide reported in an alien planet, has astronomers wondering whether they have detected the first life-forms outside our solar system.

Published

3 hours ago

April 18, 2025

Karthik Vinod

Artistic illustration of a stylized alien planet | Credit: Bhautik Patel / Unsplash

On Wednesday, a paper published in the pre-print server, arXiv did the rounds on social media after its authors claimed possible signs of life in an alien planet.

Its host star system – K2-18 – is located some 125 light years away in the direction of Leo. In 2023, the James Webb Space Telescope (JWST) detected possible signs of an exotic rare organic molecule – dimethyl sulphide – in planet K2-18b’s atmosphere. Although evidence was not conclusive enough, scientists were intrigued. This is because on earth, dimethyl sulphide is produced in biochemical reactions occurring in living organisms. As such, astronomers have taken to pondering whether K2-18b has its own share of living organisms thriving today. But these remain speculations at best.

Separating fact from fiction

Astronomers contend dimethyl sulphide’s presence isn’t necessarily the smoking gun for biological life. There is too limited data for astronomers to ever settle on positively detecting a bio-signature. Our limited understanding of what life could look like also contributes to this uncertainty. Any signs of life require a holistic examination of numerous variables. Our assumption of what constitutes bio-signatures is biased to what conditions we expect to prevail on earth.

“Phytoplankton – the foundation of the oceanic food chain,” | Credit: NOAA / Unsplash

Simpler life forms exhibit some versatility that complex organisms don’t show. For example, phytoplankton in marine environments are known to thrive in oxygen-derived conditions. But in K2-18b’s atmosphere, dimethyl sulphide occurs at concentrations many times those present on earth. Scientists are blind to the nature of chemical reactions unfolding in the atmosphere in the first place.

As such, contending theories about the surface conditions prevailing on the planet remain. In one interpretation of the facts, studies predict the planet hosts a hospitable climate. Perhaps even with an ocean, going by the 2019 detection of water vapour in its atmosphere. That is, if temperatures on K2-18b are low enough, thanks to its optimal distance from its host star, which like our sun is a dwarf star, except slightly dimmer and redder in appearance. But then if another interpretation is to go by, then the surface must be subsumed by a lava ocean. Scientists are none the wiser about these facts either.

Worlds apart

Our state-of-the-art space telescopes themselves have limited ability to capture adequate signal. For one, the K2-18 star system and our earth are separated by about 125 light years. This is about a million times that of the distance between the earth and the sun. This leaves both the host star and the planet faint sources for even JWST’s sensitive detectors. But JWST compensates for this, tracking the planet’s transit across its host star – which luckily exists along our line of sight.

From this, astronomers can retrieve tell-tale signs of the planet’s chemical makeup. This is because some of the starlight grazes past the planet’s atmosphere before it reaches JWST’s sensors. But despite JWST’s powerful sensitivity, it would require a statistically large enough sample to easily discriminate against any noise backdrop surrounding the telescope.

Saying that, more sophisticated telescopes, such as NASA’s upcoming Nancy Grace Roman Space Telescope, could possibly resolve any technical limitations to detecting fainter signs of any other chemical compounds. Thereby precision science would unlock doors, making measurements precise and put hypotheses up to the challenge.

Space & Physics

MIT Engineers Develop Energy-Efficient Hopping Robot for Disaster Search Missions

The hopping mechanism allows the robot to jump nearly 20 centimeters—four times its height—at speeds up to 30 centimeters per second

Published

1 week ago

April 10, 2025

EP Staff

Credit: Melanie Gonick, MIT

MIT researchers have unveiled an insect-scale robot capable of hopping across treacherous terrain—offering a new mobility solution for disaster response scenarios like collapsed buildings after earthquakes.

Unlike traditional crawling robots that struggle with tall obstacles or aerial robots that quickly drain power, this thumb-sized machine combines both approaches. By using a spring-loaded leg and four flapping-wing modules, the robot can leap over debris and uneven ground while using 60 percent less energy than a flying robot.

“Being able to put batteries, circuits, and sensors on board has become much more feasible with a hopping robot than a flying one. Our hope is that one day this robot could go out of the lab and be useful in real-world scenarios,” says Yi-Hsuan (Nemo) Hsiao, an MIT graduate student and co-lead author of a new paper published today in Science Advances.

The hopping mechanism allows the robot to jump nearly 20 centimeters—four times its height—at speeds up to 30 centimeters per second. It easily navigates ice, wet surfaces, and even dynamic environments, including hopping onto a hovering drone without damage.

Co-led by researchers from MIT and the City University of Hong Kong, the team engineered the robot with an elastic compression-spring leg and soft actuator-powered wings. These wings not only stabilize the robot mid-air but also compensate for any energy lost during impact with the ground.

“If you have an ideal spring, your robot can just hop along without losing any energy. But since our spring is not quite ideal, we use the flapping modules to compensate for the small amount of energy it loses when it makes contact with the ground,” Hsiao explains.

Its robust control system determines orientation and takeoff velocity based on real-time sensing data. The robot’s agility and light weight allow it to survive harsh impacts and perform acrobatic flips.

“We have been using the same robot for this entire series of experiments, and we never needed to stop and fix it,” Hsiao adds.

The robot has already shown promise on various surfaces—grass, ice, soil, wet glass—and can adapt its jump depending on the terrain. According to Hsiao, “The robot doesn’t really care about the angle of the surface it is landing on. As long as it doesn’t slip when it strikes the ground, it will be fine.”

Future developments aim to enhance autonomy by equipping the robot with onboard batteries and sensors, potentially enabling it to assist in search-and-rescue missions beyond the lab.