Some climate models suggest Venus could once have had liquid water and habitable temperatures, until a dramatic transformation hundreds of millions of years ago. One leading idea is that widespread vo

NASA GISS modelling suggests Venus may have held a shallow ocean for up to two billion years before volcanic resurfacing and a brightening Sun tipped it into a runaway greenhouse. A 2021 Nature study disputes it, arguing Venus never had oceans. Why its past is still an open question. Venus today is the most hostile planet in the solar system. Its surface sits at about 465 degrees Celsius, hotter than Mercury despite being almost twice as far from the Sun, under an atmosphere of carbon dioxide pressing down at roughly 90 times Ear... [3982 chars]