Gigantic Volcano Eruption Swiveled Mars' Entire Surface
We're just starting to understand the nature of Mars' surface, but as it turns out, the Red Planet once looked a whole lot different. 3.5 billion years ago, a titanic volcano eruption displaced the top two layers of the planet, and essentially tilted the entire surface 25 degrees.
According to a new study published in Nature, the volcano itself was gigantic, approximately half the size of France, and spewed molten lava for two hundred million years. This enormous amount of magma solidified into an outcropping called the Tharsis, a dome-shaped plateau that's more than 2,000 square miles wide and 7.5 miles tall.
The "anomalous" Tharsis weighs about a billion billion tons, enough weight to displace the crust and the mantle and cause it to swivel, changing the landscape of the whole planet.
Computer simulations show that if the Tharsis dome were removed today, Mars' surface would once again shift on its axis until it were restored to its original position. This new theory explains a slew of observational evidence from Mars' surface, including the position of the rivers, the placement of the frozen underground reservoir in relation to the poles, and the location of the Tharsis dome on the equator. However, the researchers state that there are still many "unanswered questions" that need to be explored in light of these new findings.