Water on Venus

Image of Venus billions of years ago

Image of Venus now

Water on Venus refers to the hypothesis that water was once on the surface of the planet Venus.

Early thoughts

Scientists and authors long proposed Venus was habitable, although information from the Soviet Unions Venera missions, and from the Pioneer Venus Orbiter probe, Magellan spacecraft and many more Venus studying spacecraft proved that Venus was the complete opposite.

Water disappearance on Venus

Several hypotheses have been considered for how Venus lost its water. One hypothesis states that when Venus had water, solar radiation was as low as 30% less than it is today. This means the habitable zone was stretched from Venus to Earth (and possibly to Mars), before eventually Solar maxima began creating greenhouse gases in Venus’ atmosphere, making the atmosphere thicker, evaporating away all liquid water on the planets surface. Studies have proven that Venus needed liquid water three billion years ago to be able to have such high concentrations of water-related minerals and gases on its surface and in its atmosphere today. However, such studies proved that the liquids would only have lasted up until 700 million to 750 million years ago, before eventually evaporating as Venus’ atmosphere heated up from the greenhouse effect.

Spacecraft discoveries

Data from the Venus Express satellite, made by the European Space Agency (ESA), took pictures of Venus, officially unveiling that Venus could’ve potentially had liquid, although how the liquid formed on Venus is still unclear. New simulations using this previous data have been created at NASA’s Goddard Institute for Space Studies in New York.

Other studies of Venus’s surface from different probes proved that hematite is present on its surface, proving water once interacted with Venus’s surface. Hematite is an iron oxide mineral that often forms if water presence is true. Hematite can also be formed within water-related processes. Either way, both sides have a similarity: Venus once had liquids on its surface. Although, hematite could form from volcanic activity and geological formations, or could originate from comets or asteroids.

Recent studies

Pioneer Venus color-coded elevation map of Venus revealing continents

Information using Venus’s cloud data prove that minimal amounts of water vapor exist in Venus’s clouds, possibly proving that Venus once had a functioning water cycle. Using image data from Magellan, scientists could fill lowlands of Venus’s surface area with water, only leaving Venusian continents visible. This maneuver done in the test further proved Venus could have been subject to possible land, meaning that hypothetical terrestrial animal could have roamed Venus at some point in its history. The test also used measurements from the Pioneer Venus project from the 1980s. Using data, scientists firmly believed that Venus could have been exposed to large portions of sunlight for 2 months, and then be exposed to no light for 2 months, evaporating or freezing leftover liquids on Venus’s surface. Later, this would destroy water-vapor molecules as the Sun’s ultraviolet radiation would spread rapidly on Venus over time, removing crucial elements from Venus’s atmosphere, like hydrogen, which is an important molecule in liquids. Hydrogen later was striped from Venus, subsequently creating a runaway greenhouse effect due to waters absence from Venus. GISS also proved that Venus had drier land then modern day Earth.

Geological surface feature hints

The Magellan probe detected valley’s and channels on Venus, which directly links to erosion of land, sedimentary deposits, and most recently and commonly volcanic activity and tectonic activity.

Most common studies of Venus’s surface from the Magellan probe prove that Venus has valley’s and channels, which aren’t directly connected to volcanic activity, but may be linked to tectonic activity on Venus. Asteroid impacts on Venus are another common phenomenon that could’ve shaped Venus’s surface to evolve with these geological features, although such an asteroid would have to be huge due to asteroids burning up in Venus’s atmosphere, and clouds, comprised of acids such as sulfuric acid.

Future learning

Illustration of NASA’s VERITAS mission orbiting Venus

NASA’s VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) mission will help look for geological surface features on Venus, with better technology then Magellan, giving a better understanding of Venus’s past, and hypothetical past presence of water. VERITAS will also analyze Venus’s surface materials and map out its surface temperatures, which could help explain the presence of water-related minerals, and may also contribute towards learning about Venus’s hydrothermal activity. Scientists will use its images and instruments that will spectroscope Venus’s surface. VERITAS will also use past and present data to analyze specific minerals and rocks with hydrated minerals or other water-related materials on Venus’s surface. This data could help scientists better understand Venus’s past climate, geological evolution and Venus’s water composition.

Mechanisms to revive liquids on Venus’s surface

Main article: Terraforming of Venus

Ways to revive such liquids on Venus’s surface is to strip greenhouse gases from its atmosphere, and replacing it with breathable gases, which will release trapped heat, cooling down the planet to an average temperature that of Earths. Over time, the reduction of such greenhouse gases will decrease Venus’s thick atmosphere, created less pressure. Using satellites that take in heat that orbit Venus on its dayside will help reduce temperatures and the cost of greenhouse gases getting back into the atmosphere. Using space mirrors, similar to that of the Znamya satellite, could expose the night side of the planet to light for the same duration as the average day on Earth. Manufacturing a proper magnetosphere will also help contribute. Using data two Japanese scientists studied anbout, it’s possible to make an artificial magnetosphere around Venus by building a system of refrigerated latitudinal superconducting rings. Using this, scientists could build an artificial magnetosphere around Venus to prevent the loss of hydrogen from its atmosphere. After all the previous processes, hydrogen must be added into Venus’s atmospheres which will help contribute to reviving liquid water on Venus’s surface. Chemical processes will make hydrogen and chemicals in its atmosphere form together, creating liquid water.