The Clouds of Venus: Hard Science Fiction

by Brandon Q. Morris

  Pancake cupolas (domes) are a distinctive feature of Venus. They are usually 25 kilometers in diameter and 700 meters high, with a central opening and many radial notches. One surmises that they were formed by a particularly viscous type of lava.

  There also are numerous lava flows (fluctus) due to the high level of volcanic activity. Mylitta Fluctus is about 1,000 kilometers long and several hundred kilometers wide. On the other hand, there are also eroded valleys, through which thin liquid lava—rather than water—must have flowed at one point. They are up to 150 kilometers long and have walls that are 100 meters high. They wind their way through the plains and eventually disappear.

  Gullies or fossae are a slightly larger valley type. They are usually at least 1.5 kilometers wide and 100 meters deep. The record-breaking Hilde Fossa is about 6,800 kilometers long, and thus even longer than Earth’s Nile River (6,650 km). These channels were probably carved by flows consisting of thin lava containing salt. A less popular theory attributes the formation of the channels to pyroclastic flows of gas and dust.

  The Interior: Venus’s Body

  Venus has a density similar to that of the Earth (5.24 to 5.52 g/cm3) and was formed in a similar part of the protoplanetary disk. Therefore, scientists assume that its interior resembles that of the Earth. However, Venus has a greater percentage of light elements than Earth—which is illogical, as it arose closer to the sun, in the zone where the heavier elements condensed first. Perhaps Earth could be a special case, if one takes the moon and the moon’s possible creation during a collision between Earth and a protoplanet as large as Mars into consideration.

  Venus should, in any case, possess a liquid iron-nickel core with a radius of about 3,000 kilometers and a temperature of about 5,000 degrees Celsius. Researchers estimate that the proportion of impurities contained in it, especially magnesium oxide (MgO) and magnesium silicate (MgSiO3), is at the most 8 percent.

  The mantle above it, composed of iron and magnesium silicate, could be 3,000 kilometers thick. Since the temperature difference between the surface and the core, and Venus’s gravitational pull, are smaller than in Earth’s case, there is also less impetus for mantle convection, which might explain the lack of plate tectonics and magnetic field. But the slow rotation of the planet also contributes to the lack of a magnetic field.

  Perhaps the top layer, the lithosphere, is thicker than Earth’s, which could account for Venus’s periodic volcanism. One can assume that the layer is 30 to 50 kilometers deep and is made up of basalt. The crust is especially thick beneath the tesserae.

  Birth and Childhood: The History of Venus

  Like the Earth, Venus originated 4.5 billion years ago in the sun’s protoplanetary disk. Naturally, the part of this disk near the sun was hotter than the portion further away from the sun. Therefore, in the inner solar system, the heavier elements condensed to form the rocky planets, while the lighter elements adhered to the nuclei of protoplanets in the outer solar system.

  From the beginning, Venus was at a bit of a disadvantage compared to Earth, because it was much closer to the sun. Researchers have come up with different scenarios regarding what consequences that relative position had. It is quite possible that Venus, too, had a good start, possibly even with tropical living conditions on its surface. At some point, perhaps between 500 million and one billion years, a greenhouse effect set in, the pace of which was much more rapid than global warming on Earth, leading to the current situation on Venus.

  On Earth, rain rinsed carbon dioxide from the air and bound it in the form of carbonates in rock. On Venus, however, which has no protective magnetic field, hydrogen, which is very light, was quickly swept away by the solar wind. That the sun shone with particular force in its early phase was a contributing factor. The percentage of heavy hydrogen (which is not so easily carried away by the solar wind, and therefore tends to remain) in Venus’s atmosphere indicates that Venus must have once possessed significantly more water than it does today.

  NASA researchers believe that Venus’s fertile phase might have been of even longer duration. They assume that Venus initially had as much water as Earth. If you then simulate the climatic development, it remained cool for a surprisingly long time, at least for two billion years. Even 715 million years ago, the surface of Venus could still have been habitable. Water clouds would have protected against the high level of solar radiation. Such clouds would have been particularly dense, due to the slow rotation of the planet.

  According to the theory, the cloud layer acted like a parasol. It could have even been a bit colder on the ground than on the Earth’s surface. At some point, however, all the oceans evaporated, and carbon dioxide began to outgas from the rock—we see the result of that on Venus today. Venus lost most of its water vapor to outer space. Hardly any is left.

  But perhaps a completely different scenario unfolded—at least that is what Japanese researchers think. In their opinion, the magma ocean on the surface of Venus, which still existed shortly after the formation of the planet, needed much longer to cool off than it did on Earth because of the much higher level of solar radiation. As a result, the water vapor in the atmosphere could not condense like on our home planet and form oceans from rain, but escaped into space and left behind carbon dioxide, which created the present situation due to the greenhouse effect. On Earth, on the other hand, life arose in the oceans and created today’s breathable atmosphere.

  Or is an entirely different model conceivable? The planetologist Huw Davies claims that he can prove that Venus was created from the collision of two protoplanets that were about the same size, which had previously both orbited the sun separately. This theory would at least explain the slow backward rotation of the planet. Venus’s seas evaporated due to the collision, and carbon dioxide was emitted in large quantities from rock, leading to the formation of today’s atmosphere.

  Visitors and Observers: The Study of Venus

  Even in antiquity, people noticed Venus as a morning and evening star. The Sumerians probably knew that they were dealing with the same object. They named the ‘star’ after their goddess Inanna. In Babylon, the goddess Inanna became Ishtar. Around 1600 BC, the Babylonians created one of the oldest documents about Venus, a Venus calendar that spanned more than 21 years. The ancient Egyptians reverted to believing that the morning and evening stars were separate entities, as did the early Greeks. Later, however, the ‘star’ was once again seen as one object and named after the Greek goddess Aphrodite, the goddess of love. The Romans named the star after their goddess of love, too, except that they named her Venus.

  For the Maya, the planet, which they named Chad Ek (Great Star), was one of the most important celestial objects. The Dresden Codex includes a complete record of Venus’s 584-day cycle. The Maya were already able to accurately calculate the Venusian cycle to one-hundredth of a day.

  In 1610, Galileo Galilei was the first person to view the phases of Venus via a telescope—which supported the heliocentric worldview. He also noticed that Venus changed its size, from which he concluded that Venus was sometimes closer to and sometimes farther away from Earth. British astronomers observed the first transit of Venus in front of the solar disk in 1639. In 1761, Mikhail Lomonosov found the first evidence of an atmosphere while viewing such a transit, and in the 19th century, people succeeded in calculating the distance to Venus.

  For a long time, astronomers thought Venus also rotated once every 24 hours. Giovanni Schiaparelli was the first to suggest that Venus orbited around the sun. However, it was only in 1961 that scientists were able to successfully measure its rotation period with two radio telescopes.

  For a long time, Venus was also expected to have a habitable surface, a tropical version of the Earth, perhaps with oceans of petroleum or CO2-rich water. Disappointment followed the first evidence (1958) of high temperatures—the Mariner 2-probe measured temperatures of 220 to 320 degrees.

  On October 18, 1967, the Soviet probe Venera-4 delivered the first batch of data from t
he atmosphere. It measured 95 percent CO2 and a pressure of 75 to 100 atmospheres. Venera-5 and Venera-6 confirmed the data. But only Venera-7 reached the surface, on December 15, 1970, and sent data from there for 23 minutes until heat and pressure got the better of it. Venera-8 measured the cloud layer in 1972 and found that it ended at an altitude of 35 kilometers. Mariner 10 (United States) discovered the high wind speeds in 1974.

  In October 1975, Venera 9 and 10 transmitted the first photos from the surface. In 1978, NASA’s Pioneer Venus Multiprobe reached the planet’s surface and survived there for 45 minutes. In 1981, Venera 13 transmitted the first color pictures from the surface. The probe set the current survival record at 127 minutes. In 1985, Vega 1 and 2 each deployed one balloon and one lander. The flying probes managed to survive at an altitude of 53 kilometers for 46 and 60 hours, respectively.

  After that, there were no probes for a few years. What we now know about the surface of Venus is based on data from the radar sensor of NASA’s Magellan probe, transmitted between 1990 and 1994. Further data were received between 2006 and 2014 from the ESA probe Venus Express. This probe was followed in 2015 by the Japanese probe Akatsuki, which provided, among other things, data on atmospheric circulation.

  Whether Venus will receive more visitors in the future is unclear, but two would-be guests have already expressed interest. NASA’s Parker Solar Probe will have flown past Venus seven times by 2024, and the ESA JAXA probe BepiColombo, headed for Mercury, will use Venus’s gravity to decelerate in 2020 and 2021.

  India is planning to launch an orbiter named Shukrayaan-1 around 2023—it is currently in the testing phase. Russia wants to launch a successor to the Venera probes of the 1970s, a ‘Venera D’ mission, by the end of the 2020s. The mission’s lander is supposed to survive much longer on the surface. Currently, however, the mission is only on the long-term-planning list.

  But there are enough ideas regarding exploring Venus. VAMP (Venus Atmospheric Maneuverable Platform), in particular, stands out from the crowd. The idea is to have an inflatable aircraft with, depending on the version, a 6 to 55-meter wingspan, and a mass ranging from 90 to 900 kilograms. Its motor could fly it at a speed of 110 km/h through the upper Venusian atmosphere. If the engine is turned off, VAMP would drop to a height of about 55 kilometers, where the buoyancy would be strong enough to stabilize it.

  HAVOC, the High-Altitude Venus Operational Concept proposed by NASA researchers, can manage without any engine. The spaceship NASA has conceptualized could explore Venus’s atmosphere for any length of time. You are already familiar with the concept from this novel. NASA researchers have not just conceived of a manned version, but also a much smaller 31-meter-long robotic variant. The critical point for such a spaceship is its entry into the atmosphere, when it must simultaneously brake and inflate itself. But NASA researchers have already come up with a plan to make sure entry into the atmosphere goes smoothly.

  Dead or Alive? Life on Venus

  It is beyond question that the surface of Venus is not suitable for life as we know it, but the constraint is already clear from the phrase, ‘as we know it.’ We are familiar with only one life-form so far, based on carbon chemistry and water. Even on Earth, however, there are extreme environments where life thrives. The whole Earth was once such a place, because its atmosphere initially contained no oxygen. What we now see as the hallmark of life was, in fact, produced by unicellular organisms during photosynthesis. The new substance in the atmosphere also extinguished an entire branch of life for which oxygen proved to be deadly.

  Today, niches still exist, for example, in undersea volcanoes, in hot springs, or even buried in the Earth’s crust, where life uses chemistry that differs from today’s norm. Even in these niches, life is mostly carbon-based, but of course that does not mean that life everywhere in the universe has to be based on carbon.

  Carbon is a very flexible element, surpassing any other in the ability to form a variety of structures. Therefore, when looking for life, it makes sense to begin by looking for carbon-based forms. But if they cannot be found, this does not necessarily mean that a planet is devoid of life. However, it would be pure speculation to apply this idea of non-carbon-based life to Venus’s surface, so I prefer to leave that to a work of fiction—whose prerogative, after all, is speculation.

  However, there are areas on Venus where the conditions are similar to those on Earth. You already know where—in the clouds. Above an altitude of 50 kilometers, we have normal Earth-like atmospheric pressure and tolerable temperatures. This was, in fact, where it was shown that various building blocks for carbon-based lifeforms are present. There is indeed enough carbon available in the form of CO2, but water and hydrogen are very scarce. Scientists know, however, that water vapor must be present on Venus, because it is required for the formation of sulfuric acid, which makes up a substantial part of the clouds.

  If microorganisms have formed there (or withdrawn to this location), they could use ultraviolet radiation from the sun as an energy source. These bacteria might use UV light to transform carbon dioxide to produce sulfuric acid. Interestingly, in the 1960s, astronomers discovered dark streaks in Venus’s atmosphere that absorb ultraviolet light. These streaks are found at altitudes of 50 to 62 kilometers.

  In addition, Venera probes found particles that are a micrometer in diameter in the clouds. These particles turned out to be rings composed of eight sulfur atoms, octasulfur, which might have been formed from a carbon ring. Each carbon atom might have been replaced in a step by step process by a sulfur atom (as in a biological process). But octasulfur also forms in a non-biological process from sulfuric acid, and it absorbs UV radiation—therefore, the ring molecules could be the cause of the dark streaks. We will only know the answer when we study the phenomenon in greater depth directly in Venus’s clouds.

  Even if the clouds of Venus prove to be home to life, that doesn’t necessarily mean that it originated there. Just as Mars fragments have reached Earth as meteorites, Earth fragments have reached Venus in the past. Bacteria that were robust enough to survive the journey could have found acceptable living conditions in the clouds.

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  Glossary of Acronyms

  AI – Artificial Intelligence

  ASCAN – AStronaut CANdidate

  AV – Autonomous Vehicle

  BCI – Brain-Computer Interface

  BSL-4 – BioSafety Level 4 (highest)

  CapCom – Capsule Communicator

  CELSS – Closed Ecological Life Support System (Spaceship garden module)

  DNA – DeoxyriboNucleic Acid

  DFD – Direct Fusion Drive

  ESA – European Space Agency

  EVA – ExtraVehicular Activity

  FSB – Federal’naya Sluzhba Bezopasnosti (Federal Security Service of the Russian Federation)

  HAVOC – High-Altitude Venus Operational Concept

  HDS – Home, Defender, Sex (robot)

  IgM – Immunoglobulin M (antibody)

  ILSE – International Life Search Expedition (fictional spaceship)

  JAXA – Japan Aerospace eXploration Agency

  NASA – National Aeronautics and Space Administration

  NOAA – National Oceanic and Atmospheric Administration

  REM – Rapid Eye Movement

  UV – UltraViolet

  VAMP – Venus Atmospheric Maneuverable Platform

  Metric to English Conversions

  It is assumed that by the time the events of this novel take place, the United States will have joined the rest of the world and will be using the International System of Units, the modern form of the metric system.

  Length:

  centimeter = 0.39 inches


  meter = 1.09 yards, or 3.28 feet

  kilometer = 1093.61 yards, or 0.62 miles

  Area:

  square centimeter = 0.16 square inches

  square meter = 1.20 square yards

  square kilometer = 0.39 square miles

  Weight:

  gram = 0.04 ounces

  kilogram = 35.27 ounces, or 2.20 pounds

  Volume:

  liter = 1.06 quarts, or 0.26 gallons

  cubic meter = 35.31 cubic feet, or 1.31 cubic yards

  Temperature:

  To convert Celsius to Fahrenheit, multiply by 1.8 and then add 32

  To convert Kelvin to Celsius, subtract 273.15

  Excerpt: The Dark Spring

  August 15, 2026, DLR Control Center, Cologne

  “I’m concerned about TIRA,” Marcel called out to him.

  Karl wiped the cold sweat from his forehead. Outside the sun was blazing but in here the air conditioning was on full. Hopefully he wouldn’t catch a cold.

  “Good morning to you too,” he said.

  “It’s almost midday.”

  “That’s true. But a few friendly words...”

  “Man, I’ve been awake since just after midnight and I still don’t know what’s wrong with TIRA.”

  The Thermal InfRAred instrument had first started causing problems shortly after the launch of the Hera probe. It just couldn’t be properly calibrated.

  “If necessary, we’ll have to do without it,” said Karl.

  “Then I’ll be calling in sick when the mission gets serious. The researchers will be breathing down our necks.”