Powerful volcanic activity literally moved the planet, according to a study published
in the journal of Nature on Wednesday. These findings join a list of other factors that may have changed Mars into the cold, dry planet
we now know.
A large volcanic structure known as the Tharsis volcanic dome caused the Red Planet's surface to tilt by 20 to 25 degrees 3 billion to 3.5 billion years ago.
Tharsis is home to the largest volcanoes in our solar system, and because of their mass they were able to spew out so much lava that the outer layers of Mars rotated around its core.
Imagine if you had a peach and you twisted the fruit's flesh around its pit — that's what happened to Mars.
Tharsis dome formed 3.7 billion years ago, and from there hundreds of millions of years of volcanic activity created a plateau on the Red Planet that weighed a billion billion tons. For reference, that's about 1/70th the mass of Earth's moon. This mass was so huge, that is caused the planet's mantle and crust to swivel around, changing the position of the planet's poles and moving Tharsis dome onto the planet's equator.
So why is this important? Scientists who conducted this research at the Universite Paris-Sud in Paris believe this changes the way we view Mars in its first billion years, which is when life may have been present on the planet. A tilt like this one would have significantly changed the planet's appearance.
These findings could explain a variety of puzzling geological features on the Red Planet, like why reservoirs of water ice on Mars are located far away from the planet's poles and why rivers formed where they did.
This study also changes a widely accepted theory that the Tharsis dome formed before 3.7 billion years ago and existed before Mars' rivers.
However, the observations now show that Mars' rivers could have formed at the same time as the Tharsis dome. It's also likely that this period of time on Mars was when liquid water was stable on the planet, and that formation of river valleys were likely caused by the volcanic activity.
This research gives scientists insight into Mars' early geology and could provide new clues in where to look for traces of life on the Red Planet.