Mars Had 400-Foot Tsunamis

Scientists have suspected for a while now that Mars once had an ocean. Now evidence has emerged that that ocean was terrifying.

According to a study published this week in Scientific Reports, new maps of the Red Planet show evidence that two huge tsunamis, each up to 400 feet high, once pummeled the planet’s surface. To some scientists, that pretty much sews up the ocean theory.

“Clearly, it's one of the implications of this work: to have tsunamis, you must have an ocean,” Alexis Palmero Rodriguez, one of the authors of the study, told BBC News.

The evidence is in Mars’ rocks. Satellite photos of the planet show a gigantic redistribution of sediments along the edge of Mars’ northern lowlands, which many experts believe is where the planet’s ocean was. Rodriguez and his colleagues say tsunamis are the only thing that could have caused such a massive redistribution.

“Features that have in the past been interpreted as relating to an ocean have been controversial; they can be explained by several, alternative processes,” Rodriguez said. “But the features we are describing - such as up-slope flows including large boulders - can only be explained in terms of tsunami waves.”

The study hypothesizes that the tsunamis occurred about 3.4 billion years ago, and were probably caused by meteors crashing into the ancient ocean.