The popular science fiction of the early twentieth century described Venus as a kind of wonderland with warm and pleasant temperatures, forests, swamps and even dinosaurs. In 1950, the Hayden Planetarium of the American Museum of Natural History offered reserves for the first space tourist mission, long before the modern era of Blue Origins, SpaceX and Virgin Galactic. The only thing that one had to do was provide your address and check the box of his favorite destination, among which was Venus.
Today, it is unlikely that those who want to be space tourists dream of going to Venus. As they have shown numerous missions In recent decades, the planet is not a paradise, but rather a hellish world of extreme temperatures, with a toxic and corrosive atmosphere and crushing pressures on the surface. Despite this, NASA is currently working on a conceptual manned mission to Venus called HAVOC (acronym in English of Operational Concept at High Altitude on Venus).
But how can this mission even be possible? The temperatures on the surface of the planet (about 460 ° C) are actually higher than those of Mercury, although Venus is approximately twice as far from the sun. They are higher than the melting point of many metals, including bismuth and lead, which may even fall as "snow"Over the highest mountain peaks. The surface is an arid and rocky landscape formed by extensive basaltic rock plains dotted with volcanic formations, and several mountainous regions as large as continents.
The planet is not a paradise, but rather a hellish world of extreme temperatures, with a toxic and corrosive atmosphere and crushing pressures on the surface
It is also young from the geological point of view and has suffered episodes of catastrophic surface renovations. These extreme episodes are caused by the accumulation of heat below the surface, which eventually causes it to melt, expel heat and re-solidify. Without a doubt, it is a frightening prospect for any visitor.
Float in the atmosphere
Luckily, the idea behind NASA's new mission is not to land people on the surface, but to use its dense atmosphere as a basis for exploration. An exact date for a HAVOC type mission has not yet been publicly announced. It is a long-term plan that will depend first on the success of the small test missions. Right now, with the current technology, this mission is really possible. The plan is to use spacecraft that can keep flying in the upper atmosphere for long periods of time.
Surprising as it may seem, the upper atmosphere of Venus is the closest place to Earth in the solar system. Between 50 and 60 km altitude, the pressure and temperature can be comparable to some regions of the lower atmosphere of the Earth. The atmospheric pressure in the Venusian atmosphere at 55 km is approximately half that of the pressure at sea level on Earth. In fact, it would be fine without a pressure suit because it is more or less equal to the pressure of the air at the top of Mount Kilimanjaro. Nor would it be necessary to isolate oneself since the temperature there oscillates between 20 and 30 ° C.
The atmosphere above this altitude is also dense enough to protect the astronauts from the ionizing radiation from space. The fact that the Sun is closer allows for more solar radiation than on Earth, which can be used to generate energy (approximately 1.4 times more).
The conceptual spacecraft would float around the planet driven by the wind. To facilitate this, it could be filled with a mixture of respirable gases such as oxygen and nitrogen, which would provide buoyancy. This is possible because the breathable air is less dense than in the atmosphere of Venus and, therefore, would be a lifting gas.
The atmosphere of Venus is formed by 97% carbon dioxide, approximately 3% nitrogen and trace amounts of other gases. As everyone knows, it contains a pinch of sulfuric acid that forms dense clouds, and is one of the main elements that create its visible brightness when viewed from Earth. In fact, the planet reflects roughly 75% of the light it receives from the Sun. This highly reflective layer of clouds is at an altitude of between 45 and 65 km, with a mist of sulfuric acid droplets below up to about 30km. Therefore, the design of the special ship would have to resist the corrosive effect of this acid.
Fortunately, we already have the necessary technology to solve the problem of acidity. Several materials that are marketed, such as Teflon and some plastics, have a high resistance to acid and could be used for the outer coating of the aircraft. Considering all these elements, it would be possible to walk on a platform outside the aircraft, carrying only one air reserve and one chemical protection suit.
Life on Venus?
The surface of Venus was mapped from its orbit with a radar in the Magellan mission U.S. However, only a few places on the surface were visited during the series of Venera missions of Soviet probes in the late 1970s. These probes brought the first – and so far only – images of the surface of Venus. Of course, the conditions on the surface seem totally uninhabitable for any kind of life.
However, the upper atmosphere is another story. Some types of extremophile organisms that already exist on Earth could withstand the conditions in the atmosphere at the altitude at which the HAVOC could fly. Certain species such as Acidianus infernus They can be found in highly acid lakes of Iceland and Italy. It has also been discovered that there are aerial microbes in the clouds of the Earth. None of this shows that there is life in the atmosphere of Venus, but it is a possibility that could investigate a mission like the HAVOC.
The current climatic conditions and the composition of the atmosphere are due to a greenhouse effect runaway (a extreme greenhouse effect that can not be changed) that transformed the planet, a world "twin" cozy as Earth at the beginning of its history. Even though currently it is not foreseen that the Earth faces a similar extreme scenario, demonstrates that drastic changes can be produced in a planetary climate when certain physical conditions occur.
If we test our current climate models using the extremes seen on Venus, we can more accurately determine how different effects that alter the climate can produce drastic changes. Therefore, Venus provides us with a means to test the extremes of our current climate models, with all the inherent consequences for the ecological health of our planet.
We still know relatively few things about Venus, even though it is our closest planetary neighbor. In the long run, learning how two similar planets can have such different backgrounds will help us understand the evolution of the solar system, and perhaps even that of other star systems.
Gareth Dorrian is a postdoctoral research associate in Space Science at the University of Nottingham Trent. Ian Whittaker He is a professor at the University of Nottingham Trent.
Disclosure clause. The authors are not employees, nor consultants, nor do they own shares, nor do they receive funding from any company or organization that may benefit from this article, and they have declared no relevant links beyond the aforementioned academic position.