Venus may have been habitable for billions of years: NASA Study

Venus may have hosted liquid water for 2-3 billion years, until a dramatic transformation starting over 700 million years ago resurfaced around 80 per cent of the planet, according to a NASA study.

The research gives a new view of Venus's climatic history and may have implications for the habitability of exoplanets in similar orbits.

Forty years ago, NASA's Pioneer Venus mission found tantalising hints that Earth's 'twisted sister' planet may once have had a shallow ocean's worth of water.

To see if Venus might ever have had a stable climate capable of supporting liquid water, researchers from NASA Goddard Institute for Space Studies (GISS) in the US created a series of five simulations assuming different levels of water coverage.

In all five scenarios, they found that Venus was able to maintain stable temperatures between a maximum of about 50 degrees Celsius and a minimum of about 20 degrees Celsius for around three billion years.

A temperate climate might even have been maintained .