Back in 1859, more precisely, on September 1st, the English astronomer Richard Carrington saw something peculiar on the surface of the Sun: two stains of acutely white light exploding from a bunch of dark sunspots.
Five minutes later, they disappeared, but later that night, luminous aurora showed up in the sky until Havana and Honolulu. All over the world, telegraph communications have been interrupted, and some of them caught fire.
A Rare But Violent Solar Event
What Carrington noticed was a billion tones of plasma being ejected from the Sun‘s surface and thrown into space at over 1,300 times the speed of sound. Even though the majority of those events do not hit Earth, this one was a clear shot. It was dubbed ‘The Carrington Event,’ and produced the most massive geomagnetic storm in history.
Solar activities of this level are incredibly rare, but what if it were to take place again? The effect could be violently serious, and that is the reason why governments all over the world are focusing on ‘space weather’ now.
Space weather consists of the environmental settings in Earth‘s vicinity triggered by magnetic fields, radiation, and matter thrown off by the Sun. Last month, the US House of Science, Space, and Technology Committee passed a regulation that makes investments in space weather forecasting a priority.
To better determine future space weather events, astronomers must look at the source of it: the Sun. Back in 2018, NASA launched the Parker Solar Probe, which was programmed to fly at a closer distance to the Sun than any prior mission, in order to analyze the star’s atmosphere and corona. On February 9th, the European Space Agency (ESA) will launch its own expedition, the Solar Orbiter, which will be capable of looking straight to the Sun. The instruments on board of the satellite will allow it to examine the three most common kinds of solar activity that trigger space weather: solar flares, solar energetic particles, and coronal mass ejections.
Solar flares are unexpected beams of enhanced brightness, but the majority of their energy is not visible to the naked eye, as they are formed out of violent bursts of ultraviolet and X-ray radiation. If aimed towards Earth, they are able to interrupt radio communications. The X-ray can heat the outer atmosphere as well, forcing satellites placed in low orbits to lose altitude.
Researchers pretty much know how solar flares acquire their power and are also aware that they appear near sunspots. However, the fundamental mechanisms are not yet understood, and current techniques of flare protection are not many.
Solar Energetic Particles
Similar to the massive particle accelerator, at times, the Sun ejects jets of high-energy protons and electrons into space. Moving at almost the speed of light, these solar energetic particles can get to Earth in about an hour, passing through the protective layers of the magnetic field, and sometimes, getting to the surface. If they were to hit our planet, electronics implemented into planes would be destroyed, and air travelers would be subjected to massive amounts of radiation.
Coronal Mass Ejections
Probably the most worrisome component of solar activity, coronal mass ejections are explosions on the surface of the Sun that make massive areas of the corona go off. These activities are not as fast as solar flares or energetic particles and can take between one to four days to get to Earth.
When they reach our planet, they generate a geomagnetic storm which presses one part of Earth‘s magnetosphere while expanding the other. When the ‘spring’ balances, the pressure is sent back into the upper atmosphere. Coronal mass ejections can trigger mass power outages and interruption of telecommunication services, as well as GPS.
The probability of such an event varies, with some reports claiming 12 percent in the next decade. However, newer research has estimated a more realistic likelihood, between 0.46 percent and 1.88 percent.
Ultimately, the weather in space may not be so threatening to our safety than the weather on Earth.
Paula is an outstanding reporter for Henri Le Chat Noir, always finding new and interesting topics to bring to the portal. She mostly crafts Science and Technology news articles, covering everything one needs to know about those niches. Paula studied at Concordia University.