The US Spirit rover on Mars has seen a UFO streak across the Red Planet sky.
Astronomers say it could be the first meteor seen from the surface of another world, or a redundant orbiting spacecraft sent to Mars 30 years ago.
'We may never know, but we are still looking for clues,' said Dr Mark Lemmon, from Texas A&M University.
Whatever it was, Spirit was lucky to catch sight of the UFO as the rover's main mission is to look downwards to study rocks and soil on the planet.
I can almost read the argument now about UFOs existing on every planet where we've been. Sadly there are more prosaic explanations. Prosaic explanations are not nearly as much fun.