Chasing the Aurora
Imperial's role in helping aurora hunters on their quest for the Northern Lights
Yaké nagas are a gift from the Creator, they can represent our Ancestors as well as loved ones who have recently made the journey to the next world. They are sending messages of goodwill to us on Earth: ‘You don't need to be sad anymore, keep living a good life there and one day we will see each other again.’”
Joe Bailey was raised by his grandparents in northern Canada – in a small town with only 19,000 inhabitants called Yellowknife. Surrounded by the cold landscape, Joe’s surroundings were often illuminated by the Northern Lights, or the yáke nagas, in Dene, the language spoken by many First Peoples.
Joe is the founder of North Star Adventures, the world’s first aurora-hunting company, and goes by ‘Joe the Aurora Hunter’ on his Instagram and amongst fellow aurora enthusiasts. He is one of many people across the world who devote their lives to chasing these natural projections that illuminate the night sky.
These hunters used to rely on weather forecasts, looking for cloudless nights in hopes that an aurora would be visible, if one showed up at all. But now, they have a much more sophisticated tool in their back pocket: a satellite orbiting the Sun, 245 million kilometres from Earth, and a team of scientists from Imperial College London.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
Ribbons of green northern lights above a landscape.
In medieval Europe, the aurora borealis were often interpreted through religious or supernatural lenses. They were seen as omens, warnings, or even divine manifestations. The lights inspired myths, folklore, and cultural traditions for centuries, shaping the identity and heritage of indigenous peoples in regions such as Scandinavia, Canada and Alaska.
With the advancement of technology and photography, scientists can now study auroras in greater detail, leading to a better understanding of their nature and causes. There are now scientific communities dedicated to predicting the patterns of the Northern Lights, informing aurora hunters like Joe, who scour the world look to photograph the spectacular light displays and spread their stories far and wide.
Joe said that in Yellowknife, clear skies usually mean a 98% chance of seeing an aurora, but when conditions are cloudy, aurora hunters need to use their own skills and intuition to track it.
“On some nights, with heavy snowfall and when chances are very bad, there may be just a small opening in the clouds or clear sky where we can find them,” he said, “That's the advantage of aurora hunting, we can move around to various locations to find the aurora.”
But intuition is now not the only tool that Joe has. Aurora hunters often use data measuring the frequency of solar flares, which can reveal clues regarding the intensity and location of the Northern Lights.
A research group at Imperial College London have a website which provides live data regarding these solar flares, which they also regularly post on their Twitter. Imperial’s Solar Orbiter project, run by the Space and Atmospheric Group in the Department of Physics, actively monitors solar winds and gives scientists live updates about ejections of charged particles from the Sun.
Aurora borealis are a natural phenomenon that occurs when charged particles from the Sun interact with Earth's atmosphere.
The Sun continuously emits a stream of these charged particles, primarily electrons and protons, known as the solar wind. These particles travel through space and occasionally interact with Earth's magnetic field.
Earth's magnetic field, also known as its magnetosphere, extends far into space, forming a protective barrier around our planet. When the solar wind encounters Earth's magnetosphere, it creates a shockwave-like disturbance called a bow shock. Some of the charged particles are deflected around the magnetosphere, while others are trapped within it.
The charged particles that are trapped within Earth's magnetosphere are funnelled towards the polar regions by the planet's magnetic field lines. As they approach the polar regions, they collide with gas molecules in Earth's atmosphere, primarily oxygen and nitrogen.
The collision between these charged particles and gas molecules in our atmosphere transfer energy to them, which excites them to higher energy states.
As the excited gas atoms return to their original, lower energy states, they release the excess energy in the form of light. The colours of the light emitted depend on the type of gas molecules involved in the collisions and the altitude at which the collisions occur. Oxygen atoms typically produce green and red light, while nitrogen atoms produce blue and purple light.
The collective emission of light from countless collisions means these geomagnetic storms become visible to the human eye, forming the spectacular light show that we see that we dub the aurora. The specific patterns, colours, and intensity of the aurora can vary depending on factors such as solar activity, atmospheric conditions and the observer's location.
Moreover, the intensity of the Northern Lights is also heavily influenced by the 11-year solar cycle, solar activity, and specific events such as solar flares and coronal mass ejections (CMEs).
This year, the Sun is experiencing heightened solar activity as part of its natural cycle. Solar flares and geomagnetic storms are becoming more frequent and intense, resulting in more impressive aurora displays here on Earth.
Monitoring auroral activity helps scientists track and understand space weather phenomena, which can affect satellite communications, GPS systems, power grids and other technologies.
A research team at Imperial has developed a method to predict solar storms earlier than ever before.
Prior to the team’s magnetometer, predictions of solar wind activity could only be measured a couple of hours prior to their happenings, but by using data from the European Space Agency's Solar Orbiter mission, the scientists analysed the behaviour of solar storms and identified patterns up to 24 hours in advance of the storms.
By understanding patterns that were linked to the activity solar storms, for example the frequency in solar flares, Imperial scientists could make predictions early enough to provide valuable time for agencies, companies and other researchers to interpret the data and to mitigate potential implications of the solar winds.
Imperial scientists recently finished building a magnetometer (MAG) that will be used to measure solar wind on NASA’s Interstellar Mapping and Acceleration Probe (IMAP) mission. The mission is due to launch in 2025.
Professor Tim Horbury, the Principle Investigator and Lead Scientist on the project, says that IMAP will observe and map the Sun’s heliosphere – the volume of space filled with particles streaming out from the Sun, known as its the solar wind. The aim is to study how it interacts with the local galactic neighbourhood beyond, or the ‘interstellar medium’.
Imperial’s MAG instrument measures the interplanetary magnetic fields around the IMAP spacecraft, identifying shock waves and turbulence that scatter particles in the solar wind. In doing so, scientists better understand the acceleration and transportation of charged particles in the heliosphere.
The data collected by MAG is recorded and transmitted back to Earth. Using this data, the Imperial team produces a ‘wiggly, blue line’ – a measure of solar activity – that they publish live on their website and their Twitter.
IMAP magnetometer team. Credit Thomas Angus/Imperial College
IMAP magnetometer team. Credit Thomas Angus/Imperial College
However, scientists aren’t the only ones interested in the wiggly blue line. Hunters, like Joe, have been using it too: the higher the line, the more solar activity there is, and the more intense the aurora.
Professor Horbury said that aurora hunters keep a close eye on the research group’s Twitter to get advance notice of particularly spectacular Northern Lights.
Photographers even tag the researchers in their photos of the aurora – photos they were able to take as a result of the team’s data. Professor Horbury has recently seen an influx of messages, some even asking whether they should buy a ticket to Iceland that same day because of the spike in their data: “30,000 engagements on this wiggly, blue line! It’s not a cat playing piano or something, it’s just a wiggly line!”
Jean Morris, a MAG data Scientist from the Department of Physics, calibrates the measurements for the Solar Orbiter for worldwide distribution.
Sometimes it’s weird working on something that is in space. I don’t see what I work on, so I have to imagine the device I’m working with… That’s just so far away,” she said, “So it’s really nice to be able to connect the things we do to the people here on Earth.”
This project not only links the Imperial team in London, but also others researchers across the world, spanning the US, Poland, the UK and brought together by NASA.
I like to think of ourselves as a small pond with big fish,” said Dr Helen O’Brien, the Lead Instrument Manager, about the team at Imperial.
“We might be a close-knit team, but the project would not survive without each member working together. Engineers are often seen as solitary people, it’s nice to break that stereotype,” she said.
The team has begun work on a new mission called ‘HelioSwarm,’ consisting of nine magnetometers that will be launched into space. It will be the group’s third project together, and its biggest one yet.
The global scientific community, with ever-developing technologies and predictive models, shed light onto the scientific secrets of the aurora but also add another chapter to its story.
The data they collect and share doesn't just help safeguard our planet but it also fuels the passion of aurora hunters, who continue to capture and share the magic of these lights with the world.
"The aurora connects us with our Ancestors, our family members, and our friends," said Joe.
Illustrations and animations of Solar Orbiter all credit to Jacklin Kwan. Video of Aurora Borealis over Earth are credited to ESA/NASA. Photos of iMAP team credit to Imperial College London. Photos of aurora hunters and Northern Lights to Joe Bailey/North Star Adventures.
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