What would Venus look like if it had a similar amount of surface water to Earth?
A viral map highlights how terraforming Venus could result in an impressively Earth-like planet.
The map was shared in a Reddit post by a user called "Dragonite-2" on the "MapPorn" subreddit on August 21. It visualizes one of the boldest proposals for terraforming the Solar System. Although the map was shared recently, it was actually first produced and shared in January 2014 by data scientist Alexis Huet.
The map bears similarities to Aaditya Raj Bhattarai's water-filled map of Mars, which was shared on Reddit earlier this month. Proposals for terraforming elsewhere in the Solar System tend to focus on the Red Planet. One of the most popular is Elon Musk's idea for colonizing Mars. Musk plans to build a city on Mars, and then somehow release the planet's carbon dioxide stores, creating an atmosphere that humans could move around in with just a breathing apparatus.
Venus is a totally different story. Unlike Mars' comparatively tranquil surface, Venus would be tough for humans to inhabit – its surface temperature is a scorching 465 degrees Celsius, and the atmosphere's thick, acidic clouds whizz all the way around the planet in just five days.
But experts like Carl Sagan have proposed methods for terraforming the treacherous planet, and making its surface a bit more hospitable. It also has benefits over Mars – Venus is similar in size to Earth, and much closer to our planet. Mars is about twice as far from Earth as Venus.
"Dragonite-2"'s post gives an idea of how the end results of such a terraforming mission could look. The map shows a mountainous continent to the north, a flatter series of lands to the east, a series of large islands to the west, and a large archipelago to the south.
The post sparked widespread discussion. Other users shared ideas about where they would live and set up settlements on the new world: one user, called "JPRCR," wrote: "if I had to settle there, I think I would choose the massive continent on the north, probably it will have colder temperatures on the ridges and fertile valleys in the southern part."
But how accurate is the map? Paul Byrne, associate professor of planetary sciences at North Carolina State University, who has written before about Venus' surface, tells Inverse that it's perhaps best to take it with a pinch of salt.
"The map is fairly accurate, in that someone has taken the real-world digital elevation model for Venus and added a 'sea level' to it," Byrne says.
"I don't know how realistic the 'if Venus had as much water as Earth' part is, but I'm guessing that whoever made this map picked an average ocean depth for Earth and 'flooded' the Venus topography to that same depth."
That's where the realism ends, unfortunately. Byrne explains that oceans like that would create rivers, rainfall, and lakes, meaning the surface would look pretty different after erosion and other natural movements. A planet with oceans would likely have plate tectonics, which would also change the arrangement of the geographic features.
Perhaps most importantly, Byrne says, Venus' climate would be terrible for hosting oceans.
"In reality, it's not remotely realistic," Byrne says.
But that doesn't mean the map holds no value. Byrne notes that there's some evidence Venus may once have had Earth-like oceans, and it's something humanity can research in the future.
"Although a Venus with oceans wouldn't look much like the Reddit image, it is fun to think about what a blue Venus might once have looked like — and why its climate turned into the hellish world it is today," Byrne says.
How to terraform Venus – Terraforming Venus could involve various approaches. Carl Sagan proposed in 1961 using algae seeded into the clouds to photosynthesize and reduce the carbon dioxide. Three decades later, he had to admit his plan wouldn't work: the atmosphere was later discovered to be thicker than expected.
In a 1991 Journal of the British Interplanetary Society paper, scientist Paul Birch proposed using a sunshade to cool the planet, an insulating cover to stop re-evaporation, smashing an ice moon to add some water, using solar mirrors to move its orbit, and using a soletta device to create a more hospitable 24-hour day and night cycle. Birch suggested the whole process could take around 200 years.
Transforming the planet on this scale would not be an easy task. NASA engineer Geoffrey A. Landis explained in a 2011 research paper that most proposals involved trying to undo the rampant greenhouse gas effects, which would require huge amounts of energy or highly advanced technology. In practice, Landis says, these proposals are aiming to reverse climate change and return Venus to a hypothetical earlier state.
But although the relatively peaceful Mars has captured the imagination of pro-terraforming researchers, Byrne argues that Venus could be a better candidate. It's closer in size, which would make the gravity closer to Earth's. It's also likely easier to remove carbon dioxide from Venus' existing atmosphere than to try and bulk up Mars' feeble atmosphere.
"If we were to terraform anywhere, then I'd pick Venus over Mars," Byrne says. "But, to be clear: it's going to be orders of magnitude more achievable to stop fucking up our own climate here on Earth than trying to make anywhere else even remotely habitable for humans."
The lush, water-filled planet of the future could be closer than it seems.
Update 10/05 9:30 a.m. Eastern time: Updated with credit to Alexis Huet.