There has been some media buzz that some objects found on the ocean floor are evidence of alien technology. However, the Harvard astronomer’s “alien spherules” are industrial pollutants. For technical details see:

• Critique of arXiv submission 2308.15623, “Discovery of Spherules of Likely Extrasolar Composition in the Pacific Ocean Site of the CNEOS 2014-01-08 (IM1) Bolide”, by A. Loeb et al
• Anthropogenic Coal Ash as a Contaminant in a Micro-meteoritic Underwater Search