Venus was once a habitable planet with liquid water on its surface, much like our own, until runaway climate change turned it into a hell world.
New NASA computer models suggest that until 700 million years ago, temperatures ranged from 20C to 50C on Venus’ surface.
NASA’s Pioneer Venus mission spotted hints that the planet had once had oceans in the 1980s - but at the time, scientists believe that it had evaporated quickly.
But new research by the Nasa Goddard Institute for Space Science suggests that the ocean may have lasted for billions of years.
The researchers believe that a mysterious disaster 700 million years ago turned Venus into a hellish world.
Lead researcher Dr Michael Way said: ‘Something happened on Venus where a huge amount of gas was released into the atmosphere and couldn't be re-absorbed by the rocks.
‘On Earth we have some examples of large-scale outgassing - for instance, the creation of the Siberian Traps 500 million years ago which is linked to a mass extinction - but nothing on this scale.’
The find suggests that life might once have thrived there - and means that many planets spotted by telescopes could also once have hosted life, the researchers believe.
Dr Way said: ‘Our hypothesis is that Venus may have had a stable climate for billions of years.
‘It is possible that the near-global resurfacing event is responsible for its transformation from an Earth-like climate to the hellish hot-house we see today.
‘Our models show that there is a real possibility that Venus could have been habitable and radically different from the Venus we see today.
‘This opens up all kinds of implications for exoplanets found in what is called the “Venus Zone”, which may in fact host liquid water and temperate climates.’