Solar activity, which is rapidly increasing as we approach the peak of the 11-year solar cycle, may have unexpected consequences for satellites in low Earth orbit. A new study shows that magnetic storms are reducing the altitude of Starlink satellites’ Earth orbit, which could increase the risk of debris falling to Earth.
A team of scientists led by Denny Oliveira from NASA’s Goddard Space Flight Center analyzed the behavior of Starlink satellites that entered the Earth’s atmosphere from 2020 to 2024. This period coincided with the active phase of the solar cycle, when the number and strength of magnetic storms increase. The researchers found a clear pattern: increased geomagnetic activity accelerates the decline of satellites from orbit. Over the past five years, 523 Starlink satellites have de-orbited earlier than expected.
The reason is the heating and expansion of the upper atmosphere due to solar eruptions. This creates additional resistance for the satellites, which, interacting with the atmosphere, begin to descend into the dense layers of the atmosphere faster. In a strong magnetic storm, the satellite’s lifespan can be reduced by 10-12 days. It may not seem like much, but it is enough to make it difficult or even impossible to control the satellite’s return, which SpaceX usually plans to safely destroy the vehicle in the atmosphere.
High speed is a danger to the Earth’s inhabitants
The problem has another important facet: the increasing speed of satellites’ entry into dense atmospheric layers can reduce their burn-up time, increasing the likelihood that fragments will reach the Earth’s surface. In 2024, for example, a 2.5 kg fragment of Starlink fell on a farm in the Canadian province of Saskatchewan. Although SpaceX claims that the debris does not pose a threat to humans, the study shows that the risks are increasing, especially in conditions of unpredictable solar activity.
According to Harvard astronomer Jonathan McDowell, there are currently more than 7,500 Starlink satellites in orbit. In the coming years, SpaceX plans to increase this number to 42,000. This poses a serious challenge to controlling orbital traffic, especially given that other companies are also actively launching their vehicles.
Scientists emphasize that today we live in a unique era when space around the Earth is becoming increasingly dense. Satellites are de-orbiting almost every week, and it is likely that soon such events will occur almost every day. Therefore, understanding the impact of solar activity on the lifespan of satellites and the nature of their re-entry into the atmosphere is critical. This affects not only the efficiency of satellite communication systems but also the safety of people on Earth.
The study has so far been published as a preprint on the arXiv platform, so its conclusions still need to be independently verified. However, it already adds an important brick to the understanding of how the Sun affects our growing technological presence in space.
Earlier, we reported on how scientists call for Starlink launches to be suspended.
Provided by Gizmodo
