Terraforming Of Venus | How Can We Make Venus Habitable?

Ittiz

The planet Venus is referred as the "Sister Planet" of Earth. Not only is Venus similar to Earth in terms of size and mass, but, it also has about the same composition as that of Earth's. In addition to being next door to Earth, Venus also orbits the Sun in the Glodilock Zone - the region around a star where liquid water can exist. Despite these similarities, Venus is a hostile world with a super hot and dense atmosphere.

So, How can we convert this pressure cooker into a world were we can live?

What is Terraforming?

Terraforming was first coined by Jack Williamson in a science fiction short story called "Collision Orbit" published during 1942 in the Astounding Science Fiction. 

Terraforming of a planet, moon or any other body is a hypothetical process of deliberately modifying its atmosphere, temperature, surface topography or ecology to be similar to the environment of Earth to make it habitable for Earth-like life.

Proposed methods to Terraform Venus : 

In order to make Venus suitable for human, 3 major changed need to be done in the atmosphere of Venus :

• Reducing Venus' surface temperature which is about 467 degree Celsius.
• Eliminating most of Venus' 91 atm dense atmosphere of carbon dioxide and sulfur dioxide by removing it or converting it in some other form.
• Adding breathable oxygen to atmosphere.

Eliminating the dense atmosphere : 

Terraforming Venus was first proposed by legendary astronomer Carl Sagan in 1961. In his method Carl Sagan included introduction of genetically modified bacteria that will convert the carbon dioxide in the Venusian atmosphere into organic compounds. However, when this method was introduced, Venus was believed to have Earth like temperatures and few bars of pressure. Later after exploration of Venus showed its dense atmosphere, Carl Sagan noted that this approach will cover most of the planet with few 100 meters of graphite and still atmospheric pressure would remain about 65 bars.

Other possible options include converting the atmospheric carbon dioxide into carbonates of calcium and magnesium. The Venus' own deposit of calcium and magnesium can be used for the process. Once minned and exposed to the surface, they would act like a natural carbon sinks. However, considering the amount of calcium and magnesium available in Venus, this would reduce the surface temperature to only about 127°C and atmospheric pressure would nearly be 43 bars. As a result, additional amount of these elements (a lot) will be needed which will possibly be brought through asteroid minning.

One interesting method include NUKING Venus with hydrogen bombs! The hydrogen induced in the atmosphere will react with the atmospheric carbon dioxide producing carbon (graphite) and water. The water produced will likely cover 80% of the Venusian surface. However, it will be only about 10% of the amount of water on Earth. The required amount of hydrogen can be collected through the gas giants in the outer solar system.

Cooling the planet :

In order to make Venus suitable for Earth-like life, one big factor is temperature. So, in order to cool the planet, we need to stop it from heating up.

This can be done by using solar shades. The solar shade could be used to reduce the insolation received by Venus and cool it somewhat. This shade needs to be put in Sun-Venus L1 Lagrangian point. In addition to blocking the heat, the solar shade would also act as a barrier to solar winds and reduce the radiation problem on the Venus. However, the suitable size of the shade will be about four times the diameter of Venus, which means, it need to be constructed in space.

Venus can be cooled by placing reflectors in the atmosphere. The reflective balloons can be used for the purpose. If enough floating cities on Venus are established, then these cities can be used as reflectors and at the same time, simultaneously alter the atmosphere. If the reflectors are produced using carbon nanotubes or graphene then the required carbon can be produced in situ using the atmospheric carbon dioxide. Such colonies can be economically viable which will accelerate colonizing and terraforming the planet.

Challenges of Terraforming Venus : 

Terraforming is a huge process which can take decades if not centuries! In addition to this, terraforming has not been practiced in real life and is still a "hypothesis". 

Altering a planet's atmosphere is no joke. The amount of energy and resources required are, as of now, not economically and technologically viable. The material will most likely be minned through asteroids and moons. The transportation is a big challenge. With current propulsion systems, interplanetary travel takes months and years. So, unless we have a fast transport system, terraforming is out of the cards. 

Before terraforming Venus, we will need to develop fast interplanetary transport system, minning bases throughout solar system, space based industries and manufacturing and most importantly.... a global consensus and commitment towards terraforming Venus.

Potential Benefits : 

Artist’s concept of the High Altitude Venus Operational Concept (HAVOC) mission approaching the planet. Credit: NASA Langley Research Center/YouTube

One of the primary reasons for colonizing Venus, and altering its atmosphere, is to create a "backup location" for humanity. Given the proximity of Venus to Earth, the communication and the transportation is easier as compared to other locations in the solar system.

Venus' surface gravity is about 90% of what we experience here on Earth. As a result, humans on Venus will be at a far lower risk of developing health problems related to microgravity environment - like osteoporosis and muscle degradation. 

Another huge advantage is that, by altering Venus' atmosphere, scientist can learn a big deal about its effectiveness which in turn will help us solve major climate change problems on Earth. Which means, by terraforming Venus, we are not only ensuring the long-term existence of humans, but also making sure that Earth will remain a suitable place to live in future.