Starlink maps Earth's upper atmosphere in first tomographic scan

Researchers at Kyoto University have developed a method to map Earth’s upper atmosphere by using orbital data from Starlink satellites, creating a two-dimensional view of thermospheric density. The technique applies tomography to publicly available satellite information, according to a study released on August 12, 2026.

The thermosphere, a layer of neutral gas between about 100 and 1,000 kilometers above Earth, makes up more than 99 percent of the upper atmosphere. Its density affects drag on satellites, yet it is difficult to measure directly, unlike the ionized ionosphere, which accounts for less than 1 percent and can be observed through radio wave behavior.

Better thermospheric density measurements could improve predictions of satellite motion and reduce collision risks as low Earth orbit becomes more crowded. The Kyoto team estimated density around approximately 1,200 Starlink satellites flying at an altitude of 482 kilometers, using the gradual decay of their orbits to infer atmospheric drag.

The resulting snapshot at roughly 500 kilometers altitude is the first tomographic analysis of its kind, according to the researchers. The density patterns showed strong consistency with observations from the European Space Agency’s SWARM satellites, which measure density changes along their orbital paths.

The work builds on an earlier study by the same team that used Two-Line Element data from Starlink satellites to estimate how thermospheric density changed over time and altitude. The new analysis adds horizontal variation across latitude and longitude, revealing more geographic structure in the thermosphere.

Corresponding author Mamoru Yamamoto described the study as “a multidisciplinary study between space science and space engineering,” noting that deeper dialogue between the two fields is necessary. The technique could eventually support near-real-time atmospheric density monitoring around satellites, improving space weather forecasting and satellite operations.