The findings are the latest evidence indicating the existence of this hypothesized ocean, called Deuteronilus, roughly 3.5 to 4 billion years ago, a time when Mars possessed a thicker atmosphere and warmer climate.The findings are the latest evidence indicating the existence of this hypothesized ocean, called Deuteronilus, roughly 3.5 to 4 billion years ago, a time when Mars possessed a thicker atmosphere and warmer climate. The findings are the latest evidence indicating the existence of this hypothesized ocean, called Deuteronilus, roughly 3.5 to 4 billion years ago, a time when Mars possessed a thicker atmosphere and warmer climate. Science Science News | Latest Updates on Scientific Discoveries | The Hindu