While the Sun’s short-term fluctuations rarely affect our Earth at its surface, its periodic outbursts and changes in activity can wildly affect the Earth’s outer atmosphere, both by generating amazing aurorae and by causing the atmosphere to change in size over time. For low orbiting spacecraft, that change in size is a major issue as even a couple of hundred kilometers up, the rare atmospheric particles still create a drag on spacecraft, and that drag will eventually bring those spacecraft down. 

Over the past sixty some odd years of launching things into space, researchers have come to notice that when the Sun is more active, more stuff is observed to fall out of orbit, and in general, it takes more effort to keep things in orbit. This effect can have dramatic impacts on modeling where and when space junk might fall to Earth and has to be included in long- and short-term models for objects ranging from decades-dead satellites to recently misplaced Chinese rockets. 

In a new paper in The Astrophysical Journal Supplement led by Tatiana Podladchikova, a new software model is released that should allow solar radio activity to be predicted on timescales of one to 24 months, depending on the kind of activity. This software is called RESONANCE and should allow mission planners to better understand their fuel needs and how their dead missions will decay back to Earth. We are all a bit excited to see if their two-year estimates prove true, and I, for one, wish we could do this for more weather-related phenomena.

More Information

Skoltech press release

“Medium-term Predictions of F10.7 and F30 cm Solar Radio Flux with the Adaptive Kalman Filter,” Elena Petrova et al., 2021 April 27, The Astrophysical Journal Supplement