Friends, fans, co-stars and admirers of Leonard Nimoy, who died Friday at 83, quickly took to social media to mourn the man who taught everyone to live long and prosper.

Star Trek star Leonard Nimoy dies at 83

"Today, the world lost a great man, and I lost a great friend," Nimoy's Star Trek co-star George Takei posted on Facebook. "We return you now to the stars, Leonard. You taught us to 'Live Long And Prosper,' and you indeed did, friend. I shall miss you in so many, many ways."

Takei also remembered Nimoy on MSNBC's Andrea Mitchell Reports Friday, calling the erstwhile Spock "extraordinary."

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"The word extraordinary is often overused, but I think it's really appropriate for Leonard," Takei said. "He was an extraordinarily talented man, but he was also a very decent human being. His talent embraced directing as well as acting and photography. He was a very sensitive man. And we feel his passing very much, he had been ill for a long, long time. And we miss him very much. He'd been there for a long, long time, and we miss him very much."