9. THE GSO HYPOTHESIS
9.1. Object Properties
In this section, we discuss the conditions under which reflections from objects in geosynchronous orbit (GSO) could produce the observed glints. An important question is what types of object shapes and reflective geometries are capable of creating the transient signatures observed in the POSS-I plates. A rapidly spinning object may produce multiple glints during a 50-minute exposure, whereas a more slowly rotating object might generate only one or two. If we assume a fast spin rate and interpret the observed stripe length dmax as corresponding to the path traversed by the object during the exposure, we can estimate a projected velocity of approximately 0.5 arcsec/s. This is significantly slower than the nominal angular velocity of an object at GSO (∼15 arcsec/s). Under these circumstances, we might expect additional transients to be visible along the same narrow band, particularly if the image were extended. Conversely, if the object spins slowly and has only a few small, highly reflective surfaces distributed across a predominantly non-reflective structure, glints may occur only briefly during the exposure, and only at specific orientations.
To explore this further, we use the open-source graphics engine Blender to simulate how various 3D shapes could produce glinting patterns similar to those observed. We model five distinct geometries: a sphere, a multi-faceted polyhedron, a cone, a double pyramid, and a structure with two reflective panels. Each shape is composed primarily of non-reflective material, with limited flat surfaces capable of producing strong specular reflections when oriented precisely between the observer and the Sun. In addition to rotation, we allow for precession in some models, which modulates the visibility and timing of glints. The five test geometries are shown in Figure 6.
As expected, a purely spherical object does not generate short, distinct glints; flat, mirror-like surfaces are required. In the cone model, we assume that the top and bottom surfaces are reflective, yielding double glints per rotation cycle. Adding precession further restricts glint visibility, producing only a few observable flashes per exposure. The double pyramid model illustrates another plausible case: a reflective structure that becomes partially degraded over time, leaving only small reflective regions. With rotation and precession, such objects may produce intermittent glints, consistent with what we observe in the data.
