Typical hurricanes are easy to spot on satellite images – swirling clouds surround a silent eye. These storms generally form in the lowest layer of the atmosphere, closer to the Earth’s surface, and trigger heavy rains and strong winds.
But according to a recent study, space hurricanes are completely different beasts.
The research, published in the journal Nature Communications, describes the first space hurricane ever seen. Satellites observed it in August 2014: a swirling mass with a quiet center more than 200 kilometers above the North Pole.
While regular hurricanes churn the air, this space hurricane was a whirlpool of plasma, a type of super-hot, charged gas found throughout the solar system. And instead of rain, this storm brought showers of electrons.
“Until now, it was uncertain that space plasma hurricanes existed, so proving this with such an amazing observation is incredible,” said Michael Lockwood, a space scientist at the University of Reading and a co-author of the new study, in a news release.
The space hurricane was more than 620 miles wide and high in the sky – it formed in the ionosphere layer, between 50 and 600 miles high. Lockwood and his co-authors used the satellite data to create a 3D model of the storm.
Space hurricanes could wreak havoc on satellites
The space hurricane lasted eight hours, rotating in a counterclockwise direction. It had several spiral arms snaking from its center, according to the researchers, a bit like a spiral galaxy.
By connecting the satellite data to a computer model, Lockwood and his collaborators were able to reproduce the storm and discover what caused it. The results showed that charged particles emitted by the sun’s upper atmosphere, the corona, were to blame.
This constant flow of solar particles and coronal plasma is known as the solar wind; it is moving at approximately 1 million miles per hour.
“These space hurricanes must be created by unusually large and rapid transfers of solar wind energy and charged particles to Earth’s upper atmosphere,” Lockwood said.
When the solar wind hits Earth, it meets the planet’s magnetic field. Earth has such a field due to liquid iron and nickel eddies in its outer core, which give rise to electrical currents. The resulting magnetosphere protects the planet from the sun’s deadly radiation, but it also retains a small layer of plasma from that solar wind.
Solar winds usually bounce off this protective case. But sometimes, the incoming charged particles and plasma interact with the trapped plasma or with the electrical currents that generate the field. Such interactions create disturbances in the magnetosphere.
The 2014 space hurricane was one of those disturbances.
In particular, the study authors suggest that an interaction between Earth’s magnetic field and fragments of the sun’s magnetic field, carried by the solar wind, helped form the storm.
Magnetic fields generally do not mix. But if they get closer, parts of the fields can realign and sometimes even merge, forming a new pattern of magnetic energy. That’s what likely happened on the day of the space storm: an influx of solar wind energy formed a new pattern over Earth’s magnetic north pole.
Once it formed, the storm acted as a channel from space into Earth’s atmosphere, funneling some electrons past the planet’s armor.
This shower of particles could have wreaked havoc on our high-frequency radio communications, radar detection systems or satellite technology, according to the study authors. This is because charged solar particles filtering through Earth’s magnetic field are known to cause computer and circuit failures on satellites and the International Space Station. Fortunately, in this case, no problems were observed.
Other planets could have space hurricanes too
Earth is not the only planet experiencing hurricanes – similar weather patterns occur on Mars, Saturn, and Jupiter. But this is the first time scientists have detected a hurricane in the upper atmosphere of any planet in the solar system.
However, Lockwood believes that any planet or moon with a magnetosphere could experience a space hurricane. All the planets in our solar system, except Venus and Mars, have them.
“Magnetic and plasma fields in the atmosphere of planets exist throughout the universe, so the findings suggest that space hurricanes should be widespread phenomena,” he said.