An artist's rendering of what a wet, ancient Mars might look like. (Credit: Wikimedia Commons) Not only was Mars once a wet planet. New evidence, published today in Nature’s Scientific Reports, paints a picture of violent tsunamis as well.
Tsunamis on Earth are often caused by earthquakes on the ocean floor or similar events. To an extent, that’s also what happened on Mars during both its violent events. But the initial culprits in this case were giant meteorites smacking the planet. The first meteorite, which delivered a head-on blow to Mars about 3.4 billion years ago, created a 30 km (18.6 mi) impact scar while catapulting waves hundreds of meters high across vast distances.