The Rings of Venus
The closest planet in our solar system, Venus, looks suspiciously like Earth, at first glance. With a diameter of 12,104 kilometers, Venus is only a few percent smaller than Earth (12,757 kilometers). Gravity is also only a fraction less: 0.9 g. That similarity is very striking when you consider that the planets orbiting our sun vary enormously in size, from the dwarf Mercury to the giant Jupiter.
As a child I was fascinated by this twin sister of the Earth. I even drew a map, not based on any scientific knowledge, with seas, continents, mountain ranges and wave currents. The map also shows the assumed time zones and the climates according to Köppen, which I just learned about in geography class.
Unfortunately, around the same time, scientists began to understand that in many other ways, Venus doesn’t really look like our homeworld. Spaceships like the American Mariner 2 and the Russian Venera probes revealed that the planet isn’t exactly paradise. In fact, with an average temperature of 462 °C, an air pressure about 90 times higher than on Earth, an atmosphere with an awful lot of CO2 and a thick cloud cover from which sulfuric acid rains, Venus looks more like hell than hell itself.
Moreover, Venus rotates very slowly around its axis, which makes a day last more than 116 earth days. That also makes Venus a less pleasant holiday destination, let alone a nice place to emigrate to.
The ideas about terraforming, making other planets more habitable, have therefore always focused mainly on that other neighboring planet, Mars. That world ain’t much like paradise either. But the Red Planet can be terraformed, so to speak, on a rainy Sunday afternoon, compared to Venus.
Mars is only a small planet, however, so Venus remains the jackpot for terraformers. But how would you handle that? Be careful: we are going to think big. Very big. Fasten your seatbelts and suspend your disbelief!
First of all, the hellish temperature has to drop by over 400 degrees. This requires a planetary-sized sunshade to be placed at one of the so-called Lagrange points where the gravitational pull of the Sun and Venus are in balance.
Furthermore, there is very little water on Venus. And water is an indispensable ingredient in every recipe for a livable world, so it has to be imported. Fortunately, in the outer regions of the solar system, there is an abundance of asteroids made up largely of water ice. Send them at the right angles to Venus and the planet will rotate a tiny bit faster with each impact. Two birds with one icecube!
There’s also stuff we’d rather get rid off: carbon, for example. A lot of carbon. If you shoot that into space at the right angle, the planet will rotate a little faster with every shot. And since it’s a shame to waste all that material, let’s build a nice Saturn-like ring system out of it. With their shadows, these Rings cool the areas around the equator; that’s not a luxury because Venus is a lot closer to the sun than our own planet.
And at night the Rings bring light in the darkness; that also comes in handy because Venus has no moon. That will be an amazing sight: a majectic arch in the night sky, partly in the shadow of the planet itself. Dancing in the Ringlight…
Summarizing it this way, it actually sounds like a piece of cake. But there are still a few challenges. For example, what do we do with other unwanted stuff in the atmosphere, such as hydrochloric and sulfuric acid? And what can be done about the relatively weak magnetic field?
Either way, terraforming Venus is a job that will take hundreds or even thousands of years to complete. But the reward is immense: a second Earth with seas and oceans, continents and archipelagos. It may take a few centuries (or maybe millennia) but then you really have something in your hands. Enough time to work out the details.
The funny thing is: we can already draw a world map of Venus as it will appear from under that thick cloud cover. The topography of the surface has been scanned at a detailed level through radar. And almost every hole and bulge has been named by the IAU, with the catalog of Earthly goddesses and heroines as the main source. The exact coastlines will of course depend on the amount of water that can be imported, but there will be two continents: Ishtar in the Northern Hemisphere and Aphrodite around the Equator. And there are countless islands, peninsulas and mini-continents; the new Venus will be a perfect playground for water sports lovers.
It will be a nice job for the ecologists and landscape architects of the, say, twenty-eighth century, to find the right animal and plant species for the new world. But it is hard to predict at this stage how the climatic zones and landscapes will spread over the continents and islands. That depends on things like the air pressure, the final rotation speed and the system of Hadley cells that will arise from it. But let me make a speculative prognosis.
Tropics and subtropics
The areas around the equator, which are in the shadow of the Rings for part of the year, will have a rather temperate, subtropical climate. To the north and south of it are tropical rainforests that dwarf the Amazon. A little further from the equator we also find some more arid climates and even an occasional desert.
The polar regions will have a pleasant, Mediterranean climate. But with one unusual aspect: the large Sun hovers all year round just above or just below the horizon. The Land of Eternal Sunset.
It gets really cold only in the highlands of Ishtar, about five kilometers above sea level. And on the summit of Maat Mons, a shield volcano eight kilometers high, right on the equator, Venus’ own Everest. If you’re into skiing, I recommend you head for Mars.
Lord of the Rings
I’d like to write a novel situated on this Venus 2.0. In this epic story, the protagonist travels from his native land in the southern polar region, where the ring system is not visible, to a mythical city on the equator, right below the Rings. Anyway, writing a novel, although simpler than terraforming Venus, is and remains a tough job so that will take a while…