^ dunno, supposedly if a protein strand is struck by lightning singular celled organism is created. So if there was H2O on Mars, they would have needed thunder as well... Possible though.

And even though there might have been life on Mars, I doubt it was any more complex that simple cells or bacteria. It might have travelled to Earth though... but I seriously doubt life on Earth actually arrived from Mars - not impossible though.

And whatever the life might be like on Mars, it sure wasn't intelligent. There would have been marks of intelligent life if there was - city remains etc.