Space junk falls to Earth faster when sunspots peak, reshaping satellite collision forecasts

Solar emissions exert ‘drag’ on space junk orbiting Earth. From historical measurements across a period of 36 years, researchers have now shown that space junk begins to fall down much faster once the sun’s activity across the solar cycle reaches approximately 67% of its peak. This result, which is expected to hold for station-keeping satellites too, is important for better planning of space missions that avoid collisions.