From the X-Files Dept: NASA Refutes Triangular "UFO" Seen in Footage Captured by the STEREO-B Spacecraft
UFO conspiracy theorists have attempted to use publicly available NASA images to prove that the space agency must be engaging in an elaborate cover-up, calling attention to new footage captured by a telescope onboard NASA's STEREO-B spacecraft — one of a pair of probes parked on either side of the sun which, together, provide a 360-degree view of the inner solar system. The footage shows Venus, Earth and, on the opposite side of the field-of-view, a strange triangular or diamond-shape "object" entering the field-of-view of the HI2 telescope on STEREO B around December 26, 2011.
At the same time as this strange-looking feature starts being visible, the very bright planet Venus enters the HI2-B field-of-view from the lower left. Notice that Venus and the feature stay in step almost exactly opposite each other across the middle of the detector. This is not a coincidence.
The strange looking geometrical "object" is actually an internal reflection of the planet Venus within the telescope optics. This effect has been seen many times before. Here's a particularly striking example of internal reflections caused by the planet Earth as seen early in the STEREO mission, taken from NASA Stereo image artifacts pages.
The Daily Galaxy via stereo.gsfc.nasa.gov