As of my last knowledge update in January 2022, there is no credible scientific evidence supporting the existence of ancient artifacts depicting UFOs carved in stone or confirming any visit from an alien civilization. Claims of such artifacts or encounters are often associated with pseudoscience, misinformation, or conspiracy theories.

Archaeologists and historians study ancient artifacts to understand the cultures and civilizations that created them, and they use rigorous methods to interpret the historical context of these objects. While some ancient artworks and carvings may appear mysterious or enigmatic to modern observers, attributing them to extraterrestrial influence lacks scientific validity.

Similarly, claims of UFO sightings and encounters are subject to investigation by scientific organizations and are often found to have conventional explanations, such as natural phenomena, human-made aircraft, or atmospheric phenomena.

It’s important to approach such claims with a critical mindset and rely on reputable sources and scientific evidence when seeking information about ancient artifacts, UFOs, or potential extraterrestrial encounters. If there have been developments or new information since my last update, I recommend checking the latest scientific literature and news from reliable sources for the most accurate information.