Venus may have been habitable today if Jupiter had not altered its orbit


Venus is a hellish world with clouds of sulfuric acid, but new research suggests it was an Earth-like oasis billions of years ago  - and it would still be habitable if not for Jupiter. Jupiter, which is more than 2.5 times the mass of all other planets in the solar system, may have disrupted Venus's orbit to a point of dramatic changes in climate - heating up then cooling off and releasing its water into the atmosphere.

Scientist at the University of California believe Venus's orbit may have been less of a circle, but as Jupiter migrated towards, it pushed the planet even closer. The current orbit of Venus is 0.006, but the team discovered that it was once 0.3 and 'there is a much higher probability that it was habitable then.' Previous models have yet to nail down Jupiter's dance, as some project it slowly made its way towards the sun over the course of hundreds of millions of years, reports.

Others suggest the gas giant skipped directly into Mars's orbit, before making its way to its current position. What is agreed on in the scientific community is that the planet, which has a 2.5 times that mass of all the other planets combine, was capable of tugging on everything in the solar system as it shifted orbits. The team at the University of California Riverside (UCR) began the investigation into Venus by observing its orbit, which they note is 'almost perfectly circular.'

Astrobiologist Stephen Kane said: 'One of the interesting things about the Venus of today is that its orbit is almost perfectly circular.' 'With this project, I wanted to explore whether the orbit has always been circular and if not, what are the implications of that?' For their investigation, the team designed a model that simulated the solar system.

It calculated the location of all the planets at any one time and how they pull another in different directions. Scientists measure how noncircular a planet's orbit is between 0, which is completely circular, and 1, which is not circular at all. The number between 0 and 1 is called the eccentricity of the orbit. An orbit with an eccentricity of 1 would not even complete an orbit around a star; it would simply launch into space, Kane said.

Venus is currently at 0.006 but, Kane's model shows that when Jupiter was likely closer to the sun about a billion years ago, Venus may of had an eccentricity of 0.3. 'As Jupiter migrated, Venus would have gone through dramatic changes in climate, heating up then cooling off and increasingly losing its water into the atmosphere,' Kane said.

On September 14, scientists announced they had detected traces of phosphine gas in the clouds above Venus, which could be an indication that the planet supports microbial life, For that to be the case, however, Kane notes the microbes would have had to sustain their presence in the sulfuric acid clouds above Venus for roughly a billion years since Venus last had surface liquid water—a difficult to imagine though not impossible scenario.

'There are probably a lot of other processes that could produce the gas that haven't yet been explored,' Kane said. Ultimately, Kane says it is important to understand what happened to Venus, a planet that was once likely habitable and now has surface temperatures of up to 800 degrees Fahrenheit. 'I focus on the differences between Venus and Earth, and what went wrong for Venus, so we can gain insight into how the Earth is habitable, and what we can do to shepherd this planet as best we can,' Kane said.

Venus's atmosphere consists mainly of carbon dioxide, with clouds of sulphuric acid droplets. The thick atmosphere traps the sun's heat, resulting in surface temperatures higher than 470°C (880°F). The atmosphere has many layers with different temperatures. At the level where the clouds are, about 30 miles (50 km) up from the surface, it's about the same temperature as on the surface of the Earth.

As Venus moves forward in its solar orbit while slowly rotating backwards on its axis, the top level of clouds zips around the planet every four Earth days. They are driven by hurricane-force winds travelling at about 224 miles (360 km) per hour. Atmospheric lightning bursts light up these quick-moving clouds. Speeds within the clouds decrease with cloud height, and at the surface are estimated to be just a few miles (km) per hour.

On the ground, it would look like a very hazy, overcast day on Earth and the atmosphere is so heavy it would feel like you were one mile (1.6km) deep underwater.