1,200 Starlink satellites help map Earth's hard-to-observe upper atmosphere

A network of Starlink satellites designed primarily for internet connectivity is giving scientists a new way to study one of the hardest-to-observe regions of Earth’s atmosphere. According to a study by researchers at Kyoto University, publicly available orbital data from roughly 1,200 Starlink satellites were used to estimate the density of the thermosphere at an altitude of about 482 kilometres. By analysing slight orbital changes caused by atmospheric drag and applying a mathematical technique called tomography, the researchers produced a two-dimensional map showing how thermospheric density varies across different parts of the planet.Studying a difficult regionThe thermosphere extends from roughly 100 to 1,000 kilometres above Earth's surface. Although the atmosphere is extremely thin at these heights, it still contains enough gas to produce drag on satellites travelling through low Earth orbit. That drag gradually changes spacecraft orbits, making atmospheric density an important factor in predicting satellite movement.