When a car detects that it is about to suffer an impact, the airbag inflates in just a few thousandths of a second to absorb part of the energy of the crash. This prevents passengers and driver from impacting the rigid structure of the vehicle and suffering significant damage. Now let’s imagine that It would be possible to do something similar… but with the Earth. That is, in essence, what a group of American physicists propose in a study published in Space Weatherto defend our planet from the most intense solar storms.
Their idea is to deploy, only when necessary, a kind of “space airbag”: an artificial cloud of plasma capable of temporarily reinforcing the magnetic border that protects us from the solar wind. It may sound like science fiction. However, the authors, led by Brian Walshthey assure that The necessary technology already exists and, at least on paper, could reduce by half the intensity with which a large geomagnetic storm would affect the Earth.
To understand how they work, it is important to understand how solar storms work. Despite our privileged view from Earth, the reality is that the Sun is not a calm sphere. It frequently releases gigantic eruptions known as coronal mass ejections, enormous clouds of plasma loaded with particles and magnetic fields that can travel millions of kilometers to reach Earth. And they do it at one speed up to 3,000 km/s.
Most of the time our magnetosphere deflects this material without major consequences. But when the ejecta is especially intense and its magnetic field points in the right direction, both structures can be “added” through a process known as magnetic reconnection. At that moment enormous amounts of energy penetrate the Earth’s environment.
The consequences can range from spectacular auroras to interruptions in radio communications, errors in GPS systems, damage to satellites and even electrical currents capable of overloading large electrical distribution networks. The historic Carrington Event of 1859 remains the most extreme example known, although it would have much more serious consequences today due to our technological dependence.
The proposal originated in the discovery of a region formed by plasma (ionized gas composed of charged particles) called the plasmasphere around the planet. During a solar storm, some of that plasma is ejected toward the edge of the magnetosphere. Far from being a problem, This material acts as a natural shock absorber: it hinders the transfer of energy from the solar wind to the Earth’s magnetic field.
Walsh’s team wondered whether it might be possible to artificially boost that process. The proposal, dubbed StormWall, would consist of deploying a small constellation of six satellites in geostationary orbit. When solar observatories detect a particularly dangerous coronal mass ejection, the satellites would release large amounts of elements such as lithium or barium. Ultraviolet radiation from the Sun would quickly ionize these materials, transforming them into plasma.
That plasma would travel to the edge of the magnetosphere, where It would increase the density of charged particles and make it difficult to exchange energy between the solar storm and the Earth’s magnetic field. This technique would not prevent the impact of the storm, rather it would act as an airbag that would absorb part of its energy before it reached the technological infrastructure of the planet.
Walsh’s team turned to simulations to assess how feasible the project was. According to their calculations, the release of about 400 tons of material (carried by the six satellites) could reduce the intensity of a large geomagnetic storm by around 50%. It is true, it would not eliminate the phenomenon, but it could considerably reduce its effects on satellites, navigation systems and electrical networks. And that, taking into account our dependence on technology and spikes in solar storms, is much more than we have now.