Earth's View, Starlink's Shadow: An Unseen Image Unveiled
Google Earth and Google Maps users are no strangers to unexpected moments captured in time, like a plane in mid-flight. But encountering another satellite in orbit is a rare occurrence. This particular instance showcases a Starlink satellite, captured by the French Pléiades satellite, operated by Airbus Defence and Space. The timing was perfect, despite the low probability of such an event.
A Colorful Satellite
The Pléiades satellite, equipped with high-resolution imaging capabilities, doesn't just snap a single photo of Earth's surface. Instead, it captures a rapid sequence of images across multiple spectral bands: blue, green, red, panchromatic, and near-infrared. Airbus then combines these layers to create a final image that appears natural to the human eye.
When an airplane crosses the field of view during this sequence, it appears in slightly different positions in each color layer. Once the layers are combined, the aircraft's colors appear offset due to its movement between exposures.
A Low Earth Orbit Satellite's Speed
A satellite in low Earth orbit moves far faster than a commercial jet. While an airliner typically travels between 600 and 900 kilometers per hour, a satellite can exceed 27,000 kilometers per hour. This rapid movement means that during the brief interval between exposures, the satellite may cross a significant portion of the frame, causing the color layers to fail to overlap and creating a distinctive multicolored streak.
A Rare Glimpse of Starlink
This event provides a unique image of a fully deployed Starlink satellite. SpaceX typically shares images of its satellites only during deployment shortly after launch. Once operational, each Starlink satellite extends two solar panels, giving it a wingspan of about 30 meters.
It's important to note that the identity of the satellite has not been formally confirmed. A Chinese satellite was reportedly passing nearby at the same time. However, the object's appearance and orbital context strongly suggest that it was indeed a Starlink unit.
The Growing Satellite Population
Images like this are rare, but they may become more common. The population of satellites in low Earth orbit is rapidly growing, with over 10,000 active satellites in orbit, including over 7,000 Starlink satellites flying at altitudes around 550 kilometers. This places them below the typical orbit of high-resolution imaging satellites, which operate between 600 and 800 kilometers.
As a result, interference of this kind is likely to increase. Reflected sunlight from Starlink satellites is already contaminating astronomical observations, including images captured by ground-based observatories and even by the Hubble Space Telescope. The issue is expected to intensify as additional megaconstellations are deployed, making it impossible to ignore the visual footprint of commercial satellite networks.
