Back in early December, I reported that NASA’s Perseverance Rover found evidence that Mars might have been home to big tropical storms. If Mars had tropical storms, it likely had water on it, and that’s exactly what a newly released study suggests.
According to research published in npj Space Exploration, Mars had a massive ocean about 3 billion years ago, effectively making it a “blue planet” a lot like Earth is today.
Mars’ Valles Marineris is the largest canyon system in the solar system. A research team studying it found evidence that around 3 billion years ago, Mars likely hosted a massive ocean covering much of its northern hemisphere. Valles Marineris is likely where that ocean called home, as it stretches over 4000 kilometers and slices deep into the planet’s surface. In one section, called Coprates Chasma, researchers focused on geological formations known as scarp-fronted deposits, which are structures that form when rivers flow toward a standing body of water.
All of the deposits they studied sat at roughly the same elevation, suggesting a stable water level across the canyon. Based on their location, water would have been up to a kilometer deep in some spots. Since the canyon sits higher than a lot of Mars’ northern lowlands, the water couldn’t have stopped there. That means the lowlands were flooded by an ocean that spanned the entire hemisphere.
According to lead author Ignatius Argadestya of the University of Bern, this would make it the largest and deepest ocean ever identified on Mars. To put it in a much cooler way: Mars, famously nicknamed The Red Planet, was once blue.
Or, at least, theoretically. There’s a lot more studying and verification to be done before we can accept this as common knowledge.
As you can imagine, this is a pretty big deal. A stable body of water dramatically improves the odds for habitable conditions. With habitable conditions comes the inevitable question, the one we’ve been trying to answer since humanity first looked into the sky and saw a red light among the pale yellow ones: is there life on Mars?
A better question might be “Was there life on Mars?”
The post Mars Wasn’t Always a Red Planet, It Used to Be Blue appeared first on VICE.




