Flying Cities on Venus. We tell all about NASA's plans to populate the planet

Venus - Earth's "acidic" twin

Venus is similar to Earth in size and chemical composition. This pair

planets formed at about the same time, more4 billion years ago. But, apparently, this is where the similarities end. The second planet from the Sun is now not very similar to Earth - from its hot surface to the upper layers of the acid-saturated atmosphere, according to data obtained over the year from the European Space Agency's Venus Express orbiter, which launched in November 2005.

The surface temperature of Venus hovers around465 degrees Celsius, its surface pressure is about 90 times greater than that of the Earth (which is comparable to the pressure in a kilometer below sea level. The Earth's closest neighbor takes 243 days to revolve around its axis, in contrast to the rapid 24-hour revolution of the Earth Thanks to new data, scientists know that the atmosphere of Venus is composed mainly of carbon dioxide. This, incidentally, gives humanity an idea of ​​what global warming can lead. Because of the extreme heat, water is present only in the atmosphere of the planet, so there are no oceans. storms storm, and its smog-like clouds are composed of droplets of sulfuric acid (not water).

View of Venus in the hemisphere, as shown by more thanten years of radar research, culminating in the Magellan mission in 1990-1994, the center is located at 180 degrees east longitude. Image Credit: NASA / Jet Propulsion Laboratory / USGS

And all the same Venus and Earth are often compared andcalled twins. Why? This question was answered by Dmitry Titov, a scientist at the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany, and co-author of several articles in the journal Nature on the Venus Express findings.

Venus and Earth are actually twins, but who were separated at birth. The main question is why these twins are so different.

Dmitry Titov

An international team of scientists has been streaming data with Venus Express since April 2006, when it began surveying Venus. Its minimum distance to the Earth is about 40 million km.

At the equator of Venus is a layer of turbulentair flow that smoothes out at higher latitudes, notes Fred Taylor, a physicist at Oxford University and an interdisciplinary scientist who participated in the Venus Express mission. Wind speeds in the upper atmosphere are much higher than on Earth, in part due to Venus's sluggish rotation. There is also evidence of vortex air currents thousands of kilometers wide at both poles. They are similar to those that occur over the poles of the Earth during the winter months.

Solar winds (gusts of ions from the outerthe atmosphere of the Sun, capable of breaking apart the molecules with which they collide) suck in particles of the atmosphere of Venus, unravel their atoms and spit them out into space. Particulate matter in the Earth's atmosphere is largely shielded from solar winds by a strong magnetic field, which Venus lacks. Scientists have observed light, charged particles - hydrogen and helium ions - leaving the planet's atmosphere. But the researchers were surprised to find an oxygen release as well.

“Venus is very, very dry,” stresses DavidGrinspoon, an astrobiologist at the Denver Museum of Nature and Science. He adds that all the water in its atmosphere would be just over 2.5 cm deep if it were on the planet's surface. However, analysis of the water leaving Venus's atmosphere shows that many hydrogen ions are in fact a stable isotope of deuterium, which consists of a proton and a neutron (not just a proton) in its nucleus. "The amount of deuterium is an important key to understanding how much water has been lost over time," Grinspoon stresses. The researchers estimate that Venus has lost at least an ocean of water since its formation, based on deuterium particles blown away by the solar wind.

“These differences are not only due to the fact that Venusis closer to the Sun, explains Fred Taylor. “Now we know that the absence of a protective magnetic field and different planetary rotation rates also play a role in ensuring the high speed of many atmospheric processes on Venus that we observe on Earth. The new data allow us to construct a scenario in which Venus began in the same way as the Earth - possibly including the habitable environment, billions of years ago - and then evolved to the state we see now.

Where can life dwell on Venus?

For decades, Venus was carriedVerdict: It's a toxic, overheated, crushing hell where nothing can survive. But more and more often, scientists are turning a new look at the closest planetary neighbor - or at least at its clouds.

Recent research explains how microbiallife could survive in Venusian couples. If the new hypothesis is ever confirmed, it could prompt scientists to reassess how and where we seek life in the universe.

Although the surface of Venus is subject to harshpressure and temperatures, some layers of its atmosphere are quite good. Apart from Earth, Venus's atmosphere is the most habitable place in the solar system, as its pressure and temperature are in the range we are accustomed to. However, the person would not have breathable air. The problem of sulfuric acid in the atmosphere, which corrodes the respiratory system and other vital organs, also does not disappear anywhere.

Artistic concept of active volcanoes onVenus, depicting a subduction zone where the foreground crust plunges into the interior of the planet in a topographic trench. Image Credit: NASA / JPL-Caltech / Peter Rubin

Despite the harsh conditions, scientists are askingthe question is, could some almost invisible microbes be on the edge of one of the most unsuitable worlds we know of? Hardy organisms like tardigrades can survive radiation, extreme temperatures, hunger, dehydration, and even the vacuum of space. Maybe they have relatives on Venus?

Carl Sagan contemplated life in the clouds of Venus yetin 1967, and just a few years ago, researchers suggested that the strange anomalous phenomena observed when looking at the planet in ultraviolet light could be explained by something like algae or bacteria in its atmosphere.

Research published in the journalAstrobiology, lead astronomer Sarah Seeger of MIT, offers a variation on what the life cycle over Venus might look like. Seeger has been a 21st century leader in the search for exoplanets, biosignatures, and worlds similar to ours. She is currently the Deputy Director of Science for NASA's Transit Exoplanet Mission (also known as TESS).

Seeger and her colleagues suggest that the mostthe likely way for microbes to survive over Venus is in the form of liquid droplets. But such drops do not stay in place, like rain. Eventually, they grow so big that gravity takes over. In the case of Venus, this would mean droplets containing tiny life forms fall into the hotter lower layers of the planet's atmosphere, where they inevitably dry up.

“The only way to survive indefinitelyIs a life cycle that involves drying out of microbial life as liquid droplets evaporate during settling. At the same time, small dried up "spores" stop and partially populate the atmosphere of Venus, its stagnant lower layer of haze, "the authors of the study explain.

These dried-up spores will enter a kind of hibernation phase similar to what tardigrades can do, and will eventually be released into the atmosphere and rehydrated, continuing their life cycle.

However, this is only a theory. Yet NASA is even considering launching a Veritas mission as early as 2026 into orbit around Venus to study its clouds. New data from Venus and possibly new discoveries may soon appear. The forecast for the planet remains, as it has been for some time, vague.

How did NASA plan to populate Venus?

A number of agencies, including of course NASA,concentrates efforts to explore the solar system on Mars. At first glance, however, Mars doesn't seem like the best candidate. Venus is much closer - at a distance of 38 million to 261 million km compared to Mars at a distance of 56-401 million km. As already mentioned, this is the closest neighbor of the Earth.

Venus is also comparable in size to the Earth - its radius is 6,052 km, and the Earth - 6,371 km. In addition, the two planets have similar density and chemical composition.

But everything else makes it practicallyinvisible to research. Although the probes were sent to the planet's surface, they lasted only two hours at most before conditions on the surface of Venus destroyed them. These conditions include atmospheric pressure, 92 times that of Earth; average temperature 462 degrees Celsius; extreme volcanic activity; an extremely dense atmosphere composed mainly of carbon dioxide with a small amount of nitrogen; and a cloudy layer of sulfuric acid.

In general, Venus is not the best place to colonize. However, NASA believes it has a solution to send people to explore the planet - a cloud city.

Operational concept of high-altitude Venus(High Altitude Venus Operational Concept) - HAVOC - is a concept spacecraft developed by the Systems Analysis and Concepts Office team at NASA's Langley Research Center for Venus Exploration. This lighter-than-air rocket will be designed to stay above acid clouds for about 30 days, allowing a group of astronauts to collect data on the planet's atmosphere.

While the surface of Venus mayto destroy a person, the conditions above its clouds at an altitude of about 50 km are similar to those on Earth when it comes to soaring. Venus's atmospheric pressure is comparable to that of Earth, while gravity is only slightly lower. The temperature is about 75 degrees Celsius, which is higher than a comfortable temperature, but this temperature can be controlled. Finally, the atmosphere at this altitude provides protection from solar radiation.

The mission was supposed to start with a launcha robotic probe to Venus for initial checks and research. After receiving this data, the crewed mission can spend 30 days sailing over the planet; which will be followed by missions in which teams of two astronauts will spend a year each. The ultimate goal is the constant human presence in the flying cloud city.

The city was planned to be created usingexisting or near-existing technologies. If the mission were successful, it could be the beginning of the population of the colonization of the universe outside the Earth.

NASA also planned to create the conditions of Venus on Earth - a corresponding document has already been prepared, which describes the current capabilities and capabilities for performing just such tests.

“Venus itself has value as a pointdestination for exploration and colonization, but it also complements current plans for Mars, ”said Chris Jones of the Langley Research Center. As scientists assure, if Venus was first studied, humanity would have a greater advantage over the implementation of a mission to Mars on a human scale.

Unfortunately, the project is currently in the archive. When scientists will be able to return to it, it is unknown. However, NASA gave us the opportunity to see what the exploration of Venus would look like.

Could Venus have been habitable in the past?

According to computer simulations of the ancientAccording to scientists at NASA's Goddard Institute for Space Research (GISS) in New York, Venus may have had a shallow ocean of liquid water and habitable surface temperatures for up to 2 billion years of its early history.

Observations show that in the distant past onVenus could have water oceans. A similar land-ocean pattern, like the one above, has been used in a climate model to show how storm clouds could have protected ancient Venus from strong sunlight and made the planet habitable.

NASA

The results, published in Geophysical Research Letters, were derived from a model similar to that used to predict future climate change on Earth.

“Many of the tools we useto simulate climate change on Earth, can be adapted to study the climate on other planets, both past and present, explains Michael Way, GISS researcher and lead author of the article. "These results indicate that ancient Venus could have been a very different place than it is today."

Scientists have long suggested that Venusformed from components similar to those on earth, but followed a different evolutionary path. Measurements taken by NASA's pioneer mission to Venus in the 1980s first suggested that the planet might have originally had an ocean. However, Venus is closer to the Sun than Earth, and receives much more light, energy and radiation. As a result, the planet's early ocean evaporated, water vapor molecules were destroyed by ultraviolet radiation, and hydrogen flew into space. With no water left on the surface, carbon dioxide builds up in the atmosphere, leading to the greenhouse effect that has created current conditions.

Previous research has shown that howquickly the planet rotates on its axis, affects whether it has a climate suitable for life. A day on Venus is equal to 117 Earth days. Until recently, it was assumed that for the planet to have today's slow rotational speed, a dense atmosphere, similar to that of modern Venus, was required. However, newer studies have shown that a thin atmosphere similar to that of modern Earth could have produced the same result. This means that ancient Venus with a terrestrial atmosphere could have had the same rotational speed as it does today.

Another factor influencing the planet's climate isthis is topography. The GISS team postulated that there was more land on ancient Venus than on Earth, especially in the tropics. This limits the amount of water evaporated from the oceans and, as a result, the greenhouse effect of water vapor. This type of surface appears to be ideal for planetary habitation; it looks like there was enough water to support an abundance of life, and enough land to desensitize the planet to changes associated with incoming sunlight.

Way and his colleagues at GISS simulate conditionshypothetical early Venus with an atmosphere similar to that of Earth, with a day equal to the current day of Venus, and a shallow ocean according to early data from the Pioneer spacecraft. The researchers added information about the topography of Venus from radar measurements taken by NASA's Magellan mission in the 1990s and filled the lowlands with water, leaving the mountainous regions exposed like the continents of Venus. The study also took into account the ancient sun, which was 30 percent dimmer. Despite this, ancient Venus still received about 40% more sunlight than Earth does today.

The study was conducted as part of the NASA programPlanetary Science Astrobiology as part of the Nexus for Exoplanet System Science (NExSS) program, which aims to accelerate the search for life on planets orbiting other stars, or exoplanets, by combining ideas from the fields of astrophysics. planetology, heliophysics and earth sciences. The findings are of direct relevance to future NASA missions such as the transiting exoplanet satellite and the James Webb Space Telescope, which will attempt to locate possible habitable planets and characterize their atmospheres.

Future missions to Venus

How are these "sister planets" - Earth andVenus - evolved so differently, has been a burning scientific question for decades, and the proposed mission, called VERITAS, seeks to provide answers by transforming our understanding of the inner geodynamics that shaped the planet. The mission could provide insight into the evolution of our own planet and even help us better understand the rocky planets orbiting others stars.

VERITAS is being considered for selection withinNASA Discovery Program and will be operated by NASA's Jet Propulsion Laboratory in Southern California. The project partners include Lockheed Martin, the Italian Space Agency, the German Space Agency and the French Space Agency.

“Venus is like a cosmic gift as a resultaccidents, '' said Suzanne Smrekar, VERITAS Principal Investigator at JPL. "You have these two planetary bodies - Earth and Venus, which started almost the same way, but went through two completely different evolutionary paths, but we do not know why."

The latest mission to explore the surface of the planet,NASA's Magellan spacecraft, completed in 1994. Although he gave some clues to the geology of Venus, the instruments were unable to provide reliable information about the origin of many features of the planet's surface.

Proposed for launch in 2026, VERITAS willrevolve around the planet and observe through shadowy clouds using a powerful modern radar system to create 3D global maps and a spectrometer in the near infrared range to figure out what the surface is made of. It would also measure the planet's gravitational field to determine the structure of the interior of Venus. Together, these tools can provide clues about the past and present geological processes of the planet, from its core to the surface.

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