Sometimes you may have seen up at the night sky and seen a satellite passing overhead? If so, you’re not alone, and the presence of satellites in our night sky has become a much more common sight over the past decade.

The Sun’s activity can directly affect satellites orbiting Earth. During periods of heightened solar activity, powerful solar flares and geomagnetic storms can heat Earth’s upper atmosphere, causing it to expand.

As the atmosphere expands, its outermost layers become denser. Satellites in low Earth orbit then experience increased atmospheric drag, which gradually reduces their orbital energy and can cause them to descend faster than expected.

Starlink satellites are particularly exposed because they operate in relatively low orbits. In February 2022, a geomagnetic storm caused increased atmospheric drag that contributed to the loss of 38 Starlink satellites shortly after launch. A peer-reviewed study later analyzed the event and its effects on the satellites.

The issue goes beyond individual satellites. SpaceX now operates a very large constellation, while the number of objects in low Earth orbit continues to grow. Scientists are also studying concerns involving orbital congestion, collision risks, interference with astronomy, and the consequences of satellite reentry.

The bigger lesson is that even advanced space technology remains connected to Earth’s natural environment. Solar activity can change the density of the atmosphere hundreds of miles above the surface and that can directly affect spacecraft operating there.