Many of Earth’s citizens have their eyes set on Mars as a planet prime for human colonization, and much of this optimism is based on the idea that the now barren and frozen planet was once full of water and green plant life. Warming things up, as SpaceX CEO Elon Musk has posited on numerous occasions, would theoretically bring Mars back to a more Earth-like state. However, a recent study published in the journal Nature Geoscience has thrown doubts onto this restorative thinking. Rather than a world shaped by flowing rivers and lakes on the surface, the publication suggests that the red planet gained most of its liquid water-suggestive features from moving glaciers and rivers flowing beneath them.
“The southern highlands of Mars are dissected by hundreds of valley networks, which are evidence that water once sculpted the surface… Previous interpretations of the geological record require precipitation and surface water runoff to form the valley networks, in contradiction with climate simulations that predict a cold, icy ancient Mars,” the paper’s abstract states. “Here we present a global comparative study of valley network morphometry…with physical models of fluvial [river-formed], groundwater sapping [erosion] and glacial and subglacial erosion. We found that valley formation involved all these processes, but that subglacial and fluvial erosion are the predominant mechanisms.”
In other words, as theorized in this study by Anna Grau Galofre et al., titled “Valley formation on early Mars by subglacial and fluvial erosion,” Mars’ geographical features were not likely formed by rainfall from an environment similar to ours on Earth. The planet has always been much too cold to support the weather patterns needed to be possible. Of course, that doesn’t mean terraforming is out of the picture, just that it might be a newer state of existence for Mars than we thought.
Notably, Elon Musk took to Twitter this week to discuss his hopes for making things more human-friendly, even if green will be a new color for the planet. “There’s a lot of frozen CO2 & H2O on Mars. Heating the planet will densify the atmosphere. It’s solvable,” Musk tweeted in response to a discussion on the planet’s topography. The CEO has previously explained his plans for making this happen – using nuclear bombs.
“Nuke Mars! T-shirt soon,” he wrote on Twitter last year, subsequently inspiring dozens of shirt designs with the motto to go on sale. “Nuke Mars refers to a continuous stream of very low fallout nuclear fusion explosions above the atmosphere to create artificial suns. Much like our sun, this would not cause Mars to become radioactive,” he later explained. SpaceX currently sells coffee mugs with a Mars image that terraforms when heated in a show of enthusiasm for Musk’s plans.
There’s a lot of frozen CO2 & H2O on Mars. Heating the planet will densify the atmosphere. It’s solvable.
— Elon Musk (@elonmusk) August 25, 2020
Another important part of the ‘green’ Mars theory is that it bodes well for the search for ancient extraterrestrial life. NASA’s newest rover Perseverance, currently on its way to the red planet, will be exploring with astrobiology as its main mission. The rover’s landing destination will be a 28-mile-wide crater named Jezero (translation: “lake”) thought to have held water billions of years ago. NASA’s 2012 Curiosity mission found that Mars overall was rich in material that could have potentially supported microbial life, and the Perseverance mission will collect the evidence to back up that claim. That evidence, in the form of samples, will be brought back to Earth in a future mission.
A video published by Anton Petrov gives some further perspective and visuals surrounding this recent study about Mars’ icy vs. green past. You can watch it below: