Venus was theoretically able to support human life a very long time ago, a new NASA study reveals.

The study used computer modeling to determine that until about 715 million years ago, the second planet from the sun might have been habitable. It could have had an ocean made of liquid water, and “moderate temperatures," the study reports.

That’s very different from present-day Venus, where the surface temperature is a scorching 864 degrees Fahrenheit— far hotter than the melting point of lead. The atmosphere is made of carbon dioxide and nitrogen, and it’s 90 times thicker than our own planet’s, according to NASA.

Since Venus gets a lot of sunlight, eventually its ocean (if it had one) evaporated, and finally the planet’s atmosphere became the very thick, carbon-dioxide based one it is today.

The scientists, who used a computer model to simulate the planet’s climate, believe Venus might have been habitable for as long as two billion years.

“Many of the same tools we use to model climate change on Earth can be adapted to study climates on other planets, both past and present,” Michael Way, a researcher at NASA Goddard Institute for Space Studies, and the paper’s lead author, said in a statement. “These results show ancient Venus may have been a very different place than it is today.”

The new report was published in the journal Geophysical Research Letters.

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