Correlations of Starlink Satellite Flaring with UAP Observations

All-domain Anomaly Resolution Office (AARO)
1
An AARO Information Paper
Correlations of Starlink1 Satellite Flaring with UAP
Observations
December 2024
Introduction
With the advent of satellite communication mega-constellations including the SpaceX Starlink,
Eutelsat OneWeb, Amazon Kuiper, and Chinese G60 constellations, there are currently thousands
of artificial satellites in Low Earth Orbit (LEO)2 and tens of thousands more planned for launch
over the next decade [1]. Satellite flaring is an optical phenomenon which occurs when sunlight
reflects off a satellite's surfaces, such as antennas or solar panels. This paper discusses specular
and diffuse reflection of sunlight from man-made satellites and how these effects can be interpreted
as unidentified anomalous phenomena (UAP). It also provides a method for observers to determine
whether observations may be attributable to satellite flaring.
Background
Using reflected sunlight from man-made satellites to observe and track their movement goes back
to the earliest days of space exploration [2]. As noted above, several companies develop and launch
mega-constellations, providing internet access to most of the globe. Currently, there are nearly
10,000 artificial satellites in LEO and this number is expected to grow several-fold over the next
decade [1]. Figure 1 illustrates the location of Starlink satellites in orbit as of December 2, 2024,
at 11:00 AM Eastern Standard Time. As of the end of November 2024, there were over 6,700
Starlink satellites in orbit.
Figure 2 illustrates the concepts of diffuse and specular reflections, which describe how light
bounces off objects. Figure 3 shows how sunlight reflected in these two ways is directed toward
an observer on the surface of the Earth. As seen in the left side of Figure 2, diffuse reflection occurs
when light reflects from a rough or irregular surface. Light impinging upon a rough surface reflects
in many directions, which spreads the light over a large range of angles from the reflecting surface,
as illustrated by the gray colored "light cone” in the Figure 3(a). From a single observation point,
this cone of light can be visible for up to several minutes as the satellite moves in its orbit across
the sky. Additionally, the intensity of reflected light significantly decreases the further away the
observer is from the reflecting surface. At the Earth’s surface, the intensity of diffusely reflected
light from a satellite in LEO will typically have diminished to the point that the brightness is
1 Any reference to a non-federal entity is for informational purposes only and does not constitute an express or implied
endorsement of any commercial service, from AARO, the Department of Defense, or the Executive Branch. This
report focuses on Starlink satellites, but its principles are applicable for any analogous satellite constellation.
2 Altitude for Low Earth Orbit (LEO) ranges from 300km to 2,000km.