UFO debunker UFO of Interest tackled the visual phenomenon in early March, calling it out as a “recurring image artefact caused by internal reflections of a planet.”
NASA confirmed this diagnosis late last week in an update on the STEREO website.
NASA said in the update: “The strange looking geometrical ‘object’ is actually an internal reflection of the planet Venus within the telescope optics.”
This is only the latest occasion this sort of reflection has appeared in STEREO’s field of view.
An annotated look at NASA data last week revealed the Lagoon Nebula, Venus, Earth and the light artefact.