On February 10, a sudden geomagnetic storm scrapped 40 satellite chains launched by space X. Space weather experts say that as solar activity tends to become active from a minimum, the resulting solar wind will destroy more satellites < p > SpaceX, led by Elon Musk, has felt the threat of solar activity: a sudden geomagnetic storm disrupted the earth's atmosphere, resulting in the early retirement of about 40 satellite chain Internet satellites. SpaceX expects that almost all of the satellite chain satellites launched by the company in a single launch have been lost < p > but space weather experts explained that geomagnetic storms are not rare and are expected to become more frequent in the next few years. Since December 2019, the sun has started a new 11 year activity cycle. Now it is entering the peak of solar activity. It is expected that the solar activity will reach the peak around 2025 < p > tamitha SKOV, an aerospace research scientist, said: "the reason why [solar wind] was not a big problem before was that it has been in what we call the 'solar minimum' for the past three to four years." < p > it is worth noting that the latest solar minimum is almost synchronized with the surge in the number of low earth orbit satellites. According to the analysis of Bryce tech, a space industry research and consulting company, about 4000 small satellites have been launched around the world in the past four years, most of which operate in low earth orbit < p > scoff admitted, "many such commercial projects... Don't know how much space weather affects satellites, especially these small satellites." < p > solar cycle and satellite < / P > < p > geomagnetic storm originate from the solar wind generated by solar activity. The magnetic field around the earth releases the energy of the solar wind into the earth's atmosphere, resulting in the warming of the earth's upper atmosphere < p > illustration: the aurora also comes from geomagnetic storms < / P > < p > "most people really like this phenomenon, but they are not aware of the harm at all because they are concerned about the aurora," SKOV said < p > the National Oceanic and Atmospheric Administration (NOAA) set the measured geomagnetic storm intensity level to G1 to G5, and the geomagnetic storm that destroyed the satellite chain last week is expected to be G1. Erika Palmero, a research scientist at the Association for prediction Sciences, explained that G1 storms are small and "very common" and usually occur more than 1700 times in an 11 year solar cycle < p > "G5 is an extreme geomagnetic storm, which is very rare. We will find about four G5 geomagnetic storms in each solar cycle." < p > palmeiro emphasized that the G5 geomagnetic storm will pose a threat to the power grid or spacecraft operation, but it has no impact on the human body < p > palmerio said, "these geomagnetic storms do no direct harm to humans on the ground." < p > the side effect of the increase in atmospheric density is the increase in the resistance of low earth orbit satellites, which may lead to spacecraft de orbiting or spacecraft such as satellite chain satellites falling into the atmosphere and burning down < p > geomagnetic storms lead to increased radiation and damage to spacecraft. Palmeiro said the radiation would burn instruments or detectors on the spacecraft < p > SKOV stressed that the satellite chain is "very small", but it has a large solar panel, which essentially brings a "huge" drag umbrella to each satellite < p > illustration: the satellite chain satellite being deployed < / P > < p > "when it comes to resistance, this design can't be solved," SKOV said. "For many years, some people in space meteorology have been talking about the disappearance of satellite chains from the sky, because we know that it is only a matter of time before solar activity starts to become active again." < p > in addition, SKOV said that the earth's "sponge" atmosphere means that there is no specific minimum safe altitude in orbit around the earth. The recently scrapped satellite chains are all located at the altitude of 210 kilometers just launched, which is far lower than the normal operation altitude of 550 kilometers. But scoff said there is still a "possibility of resistance" in the conventional orbit of the satellite chain < p > lessons from history < / P > < p > both SKOV and palmerio emphasize that geomagnetic storms cause more damage than commonly thought, and such events caused by solar activity can be found everywhere in history < p > "in 1967, a solar storm caused the North American air defense command to lose contact with half of the satellites," SKOV said. This incident almost triggered a nuclear war < p > another solar wind in 1989 paralyzed the power grid in Quebec, Canada, suspended trading on the Toronto Stock Exchange, and malfunctioned sensors on the space shuttle Discovery. Scientists believe that the solar wind also caused the scientific observation satellite solar peak year (SMM) out of orbit < p > "it's just an appearance," SKOV added, adding that the solar wind will also have a "sustained" impact on GPS systems and satellite phones < p > the 2003 Halloween storm caused the most powerful geomagnetic storm on record. Palmeiro said that the increasing radiation has led to the destruction of various space science instruments from earth orbit to the surface of Mars < p > compared with the previous solar cycle, which peaked in April 2014, the main difference of the current solar cycle is that there are thousands of satellites in low earth orbit < p > "but it's still a wilderness," scoff said. (Chen Chen) < / P > < p >