Fixed: Earth is the only known planet to have life.

qq66 · on March 26, 2012

Fixed: Earth is the only planet known by Earth to have life.

Zakuzaa · on March 26, 2012

Fixed: Earth is the only planet known by humans on Earth to have life.

prawn · on March 26, 2012

Hate to continue the chain, but on the off-chance government organisations know more than they're letting on, we might need to extend that to "most humans". Though, in that case, it might have to be "thought by most humans"? Just speculating for the hell of it. e.g.,

Fixed: Earth is known by most humans as the only planet to have life.

rhygar · on March 26, 2012

Fixed: Earth is known by most humans as the only planet to have Earth-like life.