At the beginning of this month, sunspots continued to appear on the surface of the sun, and solar activity was more frequent, from May 3 to May 10 in a few days, the sun erupted 10 X-class flares and more than 60 M-class flares in a row, almost all of these flares occurred in the active area AR3663 and AR3664, and the intensity and frequency of solar flares in this month are extremely rare.
At noon on May 8, 2024, the Sun erupted with an X1.0 X-ray flare from the active zone 13664 near the center of the solar surface, accompanied by a total coronal mass ejection.
At that time, the solar flare released a large number of high-energy charged particles, which galloped towards the Earth at a speed of hundreds to thousands of kilometers per second, and the official warning at that time was that it was expected to reach the Earth in 2-3 days, and then cause a geomagnetic storm on the Earth.
According to the information released by the National Space Weather Monitoring and Warning Center on May 11, from the evening of May 10 to the early morning of May 11, a geodetic magnetic storm broke out in the Earth's magnetic field (kp=9). At that time, when there was a geomagnetic storm, extremely gorgeous auroras also appeared, and brilliant aurora appeared in Mohe, Heilongjiang and some parts of Xinjiang. For the average person, the most intuitive phenomenon when the geomagnetic storm phenomenon occurs is actually the aurora, especially the aurora occurs at relatively low latitudes.
Normally, the aurora phenomenon also occurs occasionally, which is a very common natural phenomenon. This is because when the high-energy charged particles from the sun enter the Earth's magnetic field at high speed, the Earth's strong magnetic field forces a part of them to concentrate along the magnetic field lines to the north and south poles.
When these high-energy charged particles enter the upper atmosphere above the polar regions, they will collide with the atoms and molecules in the atmosphere, and this extremely gorgeous aurora phenomenon will be produced. So under normal circumstances, it will only appear in the sky over high latitudes, such as the sky near the Antarctic and Arctic regions.
It can also be seen from this that there are three necessary conditions for the occurrence of the aurora phenomenon: magnetic field, atmosphere, and high-energy charged particles, all of which are indispensable. This also shows that on those planets with magnetic fields and atmospheres, there will be such extremely gorgeous auroral phenomena. Many probes and telescopes have observed various auroras in the sky over Jupiter before, which is one reason.
In the case of a geomagnetic storm, the solar wind penetrates the Earth's magnetic field much more than usual, and the aurora phenomenon will be visible not only over the North and South Pole regions, but also in some middle and high latitudes. For example, when the geomagnetic storm erupted, brilliant auroras appeared in Mohe in Heilongjiang and parts of Xinjiang.
Although the high-energy charged particles from the sun are fast and the radiation is very strong, due to the protection of the earth's magnetic field, these high-energy charged particles cannot pass through the magnetic field and the atmosphere, so they will not have any impact on the lives of ordinary people. You don't need to worry.
Although solar activity does not affect the lives of ordinary people, it does have an impact on spacecraft operating in low-earth orbit, and there have even been cases where spacecraft have been destroyed due to solar activity.
Now that China's space station is orbiting in a circular orbit of about 400 kilometers in low-earth orbit, there are three astronauts in the space station, and there are also several foreign astronauts in the International Space Station.
What about astronauts?
When the phenomenon of geomagnetic storms occurs, the most direct impact on spacecraft in low-earth orbit may be to affect their orbital altitude, and some spacecraft with very low orbits may fall into the atmosphere and burn up.
This is because these high-energy charged particles from the sun themselves have huge kinetic energy, and after entering the earth's atmosphere, they will cause the air in the upper part of the atmosphere to be constantly heated, and in the case of thermal expansion, the atmosphere in the upper layer will continue to spread outward.
Originally, the air density in the flight orbit of satellites, probes, spacecraft, and space stations was relatively low, but after the occurrence of geomagnetic storms, the air in the flight orbits of these spacecraft has increased, and the air resistance they are subjected to will naturally increase, which will make the flight speed of these spacecraft slower.
We all know that the reason why these spacecraft can fly in low earth orbit for a long time without falling off is because they fly at a high speed, and when the geomagnetic storm phenomenon occurs, they fly slower due to the increase in air resistance, and the flight orbit altitude will naturally decrease.
As their trajectory altitude decreases, they also face greater air resistance, which in turn reduces their flight speed even further, and gradually these spacecraft slowly fall into the atmosphere, and then re-enter the atmosphere and burn violently into ashes.
This is an unavoidable scenario, and if spacecraft such as the space station do not take measures to deal with it, the result may be an early return to Earth. But you don't need to worry, our space station will definitely not fall into the Earth's atmosphere because of the occurrence of geomagnetic storms.
Because geomagnetic storms are actually very common, large and small geomagnetic storms often occur, and from 2 o'clock to 8 o'clock on April 24, 2023, there was a similar extra-magnetic storm phenomenon on the earth, when there was also a gorgeous aurora phenomenon in Karamay, Xinjiang. At that time, the geomagnetic storm also affected the orbits of some spacecraft, such as the orbit of one of the continental meteorological satellites, Fengyun-3G, which was lowered by about 560 meters.
Although the orbit of Fengyun-3G, which orbits about 407 kilometers above the ground, has been attenuated due to the phenomenon of megamagnetic storms, these problems have been taken into account in the design.
Because the air density still exists in this orbit, in the year of high solar activity, the one-day orbital altitude attenuation range of the satellite can reach more than 600 meters. Since October 23, 2023, the satellite has completed more than 6 months of operational trial operation and was officially put into operational operation on May 1. In other words, the satellite was not actually destroyed due to the geodetic magnetic storm phenomenon.
As for the manned space station, that's even less to say, there's no need to worry at all. Under normal circumstances, the flight altitude of the space station assembly will also be attenuated, after all, the volume of the space station assembly is much larger than the average satellite, and the International Space Station is 110 meters long and 88 meters wide, which is about the size of two football fields.
The air resistance of such a large space station complex during daily operation is very large, and the ISS will drop its orbital altitude by about 2 kilometers every month, and sooner or later it will fall into the atmosphere if the engine is not turned on to raise the orbital altitude. Therefore, it is a normal operation for the space station assembly to start the engine to increase the altitude of the flight orbit.
Our space station is actually the same, every once in a while the engine is turned on to adjust the flight trajectory, including raising the flight trajectory. This also means that even if the geomagnetic storm phenomenon leads to an increase in the air density in outer space, resulting in an increase in the air resistance of the space station, and the flight altitude will decrease, the impact on our space station is actually very small, and we only need to start the engine to change the orbit, and the loss is just to consume some fuel. So you don't need to worry about it at all.
In addition, in order to ensure the safety of astronauts flying in orbit, we will also have a new manned spacecraft backed up on the ground. Now the astronauts of the Shenzhou-18 spacecraft are flying on the Chinese space station, and the Shenzhou-19 spacecraft is already on standby, and if necessary, the Shenzhou-19 spacecraft can be launched to the Chinese space station to pick up the astronauts.