Avi Loeb recently recovered metallic “spherules” from the ocean floor that he believes could be interstellar in nature. But don’t draw any conclusions, yet
Oumuamua
The solar system is vast & the space between our star system and our closest neighbor, Proxima Centauri, is even more vast
"A more exotic scenario is that 'Oumuamua' may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization"