universetoday.com
Rover Sees a UFO? - Universe Today
While watching the night sky with its panoramic camera, NASA's Spirit rover saw something surprising - a streak of light that was probably the brightest object in the sky. But what was it? It could have been a meteorite, or an old, dead spacecraft that orbited overhead. Based on the direction of the trail, the only spacecraft in that orbit, moving at that velocity would be Viking 2.