A strange rock formation captured in NASA rover footage has ignited fresh viral speculation regarding alien life on the Red Planet, after a prominent UFO researcher pointed out what appears to be a mysterious rectangular doorway carved into a Martian cliffside.
The anomaly, estimated by online enthusiasts to stand roughly 6ft tall, quickly triggered intense internet debates across social media platforms over whether an ancient extraterrestrial civilisation could have left behind an underground sanctuary.
However, planetary scientists and geological experts have stepped in with a much more grounded explanation, pointing out both the optical illusion of scale and the natural tectonic processes at work across the dusty landscape.
According to The Daily Star, researcher Scott C. Waring pointed out a mysterious rectangular 'entrance' or 'doorway'.
As millions of digital sleuths share side-by-side comparisons of the anomaly, space agencies emphasise that pareidolia and wind-scoured bedrock frequently combine to create bizarre geometric shapes that easily fool the human eye.
The photo was taken by NASA's Curiosity rover and shows a small, dark opening in a rock. Its shape has led UFO and conspiracy theorists to call it a doorway or entrance created by another civilisation.
The discovery has once again raised the familiar question: Could Mars once have been home to a different life form?
It's impossible to come to any conclusions from the photograph alone. There is no evidence that the formation was made by extraterrestrial beings, and NASA has not identified it as an artificial structure.
In fact, NASA itself has previously addressed a remarkably similar-looking feature photographed by Curiosity.
In May 2022, Curiosity photographed a rock formation known as East Cliffs that had an opening which looked like a mini doorway.
NASA's official description called it a 'door-shaped fracture' seen at East Cliffs. The image showed a narrow, dark opening in the rock that immediately prompted comparisons with science-fiction-style entrances.
However, the apparent doorway is considerably smaller than the impression made by the photo. Without an obvious object beside a figure to provide scale, the human brain can easily see a small detail as something much bigger. But that hasn't stopped the new image from causing speculation.
Mars has become a magnet for claims about strange structures, mysterious objects and possible evidence of alien civilisations.
The planet's surface has countless rocks, cliffs, cavities and fractures; under particular lighting conditions, some things can look surprisingly familiar.
NASA has previously documented unusual Martian formations that initially appeared mysterious but turned out to be geological features.