Venus Might Be Livable 700 Million Years Ago, Scientists Say

As for Venus, scientists believe that there cannot be life on this planet because of its extremely high temperatures and acid clouds. However, a recent study has rebutted this view. About 2-3 billion years ago, Venus once had temperatures that were suitable for liquid water, but this ended more than 700 million years ago.

Researchers have designed computer simulations, with assumptions of different amounts of water that ever presented on the planet's surface. The results showed that Venus once maintained a stable temperature between 20°C and 50°C. Until 700 million years ago, there were a series of events taking place in Venus's atmosphere, leading to the release of carbon dioxide on the planet and the changes in climate. Scientists also applied a common 3D circulation model to identify the increase in solar radiation over time and the development of atmospheric components.

The study was presented at the EPSC-DPS 2019 Joint Meeting by Michael Way in Goddard Space Science Institute. It has provided a new understanding of Venus's climate and showed the potential of exoplanets in similar orbits that could support life.

In a collaboration of Dr. Way and Anthony Del Genio, a series of five simulations of Venus's topography was created, among which three simulations are considered to be the same terrain as today in Venus. The two researchers simulated an ocean with an average depth of 310m, shallow water with an average depth of 10m and some water in the soil. They also compared and analyzed two simulations: one had terrain of the Earth and the average ocean depth of 310m Meanwhile, the other was completely covered by an ocean with an average ocean depth of 158m.

General understanding supports that Venus is located outside the inner boundary of the Goldilocks Region, and therefore, it will never have any signal of life on the planet. However, this research provided a different insight. In addition, previously, NASA through its Pioneer Venus mission succeeded in finding shallow water on several of Venus's surface, which was significant signals of habitable life.

In fact, to conclude whether there was ever life on Venus, two criteria were needed: the initial cooling rate and the appearance of the resurfacing event that changed the environment. Liquid water was also a necessary element, but this factor is not enough to reach a conclusion.