科研团队通过追踪Starlink及其他卫星星座的轨道衰变，创建了一套新的大气密度监测体系1。该方法通过测量卫星受到的大气阻力变化来反映上层大气的日常波动，为轨道预测和碰撞避免模型的改进提供了数据支撑1。
截至报道时间，Starlink已有超过11,000颗卫星在轨，大多数在480公里高度运行1。监测样本包括1,000颗2026年前发射的Starlink卫星1。2026年的观测数据显示了显著的波动幅度：8月10日记录到最低下沉速率19.7米/天，而1月20日地磁暴期间达到最高值127.6米/天，两者相差逾6倍1。在127.6米/天的下沉速率条件下，一颗失效卫星将在约一年内坠落地球；而在40米/天的速率下则需约四年1。
1月19日至21日期间发生的G4级地磁暴（Kp值9-，Ap值144）引发了大气密度的急剧变化，下沉速率增加了约5倍1。研究通过对比Planet Labs Doves卫星的实际衰减数据验证了监测指数的准确性，两者在暴风周期间的变化一致性达到99%——Doves卫星上升2.74倍，而Starlink指数上升2.71倍1。研究还跟踪了Planet Labs SuperDoves（107颗）、Amazon Kuiper（391颗）和Eutelsat OneWeb（651颗）等卫星星座，其中Kuiper与Starlink的日均关联系数达到0.941。
Researchers have transformed orbital data from Starlink and other satellite constellations into a real-time atmospheric density index, providing unprecedented insights into daily variations in Earth's upper atmosphere.1 By measuring atmospheric drag effects on satellites in low Earth orbit, scientists can now track subtle changes in air density at altitudes where these spacecraft operate.1
The monitoring system tracks approximately 1,000 Starlink satellites launched before 2026, with most operating at 480 kilometers altitude.1 Satellite descent rates serve as the primary indicator of atmospheric conditions: in August 2026, satellites sank at a rate of 19.7 meters per day during the calmest atmospheric period, while descent rates surged to 127.6 meters per day on January 20, 2026, during a severe geomagnetic storm—a sixfold increase.1 These variations have direct implications for orbital longevity; at the peak descent rate of 127.6 meters per day, a non-functioning satellite would deorbit in approximately one year, whereas at 40 meters per day the same process requires about four years.1
The research validates the index's accuracy through independent data. A G4-level geomagnetic storm occurring January 19–21, 2026, with a Kp index of 9– and Ap value of 144, triggered a fivefold increase in descent rates.1 Comparison with actual decay measurements from Planet Labs Doves satellites showed 99 percent correlation during the January storm period, with Doves rising 2.74 times and the Starlink index rising 2.71 times.1 The monitoring system also tracks additional constellations including Planet Labs SuperDoves (107 satellites), Amazon Kuiper (391 satellites), and Eutelsat OneWeb (651 satellites), with Kuiper and Starlink showing a daily correlation coefficient of 0.94.1 SuperDoves maintained typical descent rates around 62 meters per day in 2026, with median satellite altitude declining 15.5 kilometers between January and August.1
This atmospheric density index promises improvements to orbital prediction models and collision avoidance systems by providing detailed, real-time measurements of upper atmospheric conditions.1
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