Today physicist Stephen Hawking and billionaire Yuri Milner announced an ambitious plan to send thousands of tiny robots to Alpha Centuri, a star that's 4.37 light-years away.

The $100 million project — called Breakthrough Starshot — is undeniably ambitious but seemingly not out of reach.

And that got two Starshot team members thinking: If we can do it, why not aliens? What if they've already visited our own solar system with tiny robots? Would we have noticed?

Harvard astrophysicist Avi Loeb and Ann Druyan — an author, TV producer, and longtime collaborator/spouse of Carl Sagan — brought up the radical if not creepy idea during Monday's big announcement of Starshot.

"You must wonder if there's a possibility that such things are flying near us from other civilizations," Loeb speculated. "They're moving so fast and so small, they don't transmit much energy — that we won't notice."

"Is that a solution to the Fermi paradox?" Druyan asked.

"It's one possibility," Loeb replied.

Yea, sure. No one's noticed. Excuse me while I gag. To read more, click here.