If you don’t know much about planet Venus, it is similar in size and shape to Earth but that is where all the similarities stop. It has a toxic atmosphere consisting of carbon dioxide and nitrogen that traps in heat creating the runaway greenhouse effect seen there today and temperatures hot enough to melt lead. The conditions of Venus could equate to what many people consider hellish—intense heat, nonstop volcanic activity, and a crushing atmosphere 90 times thicker than that of Earth’s—making it a completely uninhabitable place.
However, astronomers from NASA have just discovered that Venus might have been habitable for billions of years before becoming what it is today. With that said, if we had a spaceship that could travel back in time, we might come across a Venus that looked more like the Earth we live on.
The discovery was published in the journal Geophysical Research Letters after NASA climate modeling found evidence suggesting that “Venus may have had a shallow liquid-water ocean and habitable surface temperatures for up to 2 billion years of its early history.”
From Scientific American:
The team first simulated how the Venusian climate might have looked 2.9 billion years ago. Such an ancient date required the researchers to make a few educated guesses about the early planet, such as assuming it had a shallow ocean just 10 percent the volume of that on Earth today. But the results were clear—2.9 billion years ago the second rock from the sun could have had a balmy Earth-like temperature that hovered around 11 degrees Celsius. The team then ran the model for a later Venus some 715 million years ago and found that even under the sun’s heightened heat, the planet would have warmed by only 4 degrees Celsius since that earlier time. Such a slight increase in temperature would have allowed the planet’s liquid ocean to persist for billions of years.
Venus, being so close to the sun, brings up the question of how water could be present for so long there. Astronomers theorize the presence of clouds would account for that.
Here is a video from It’s Okay to Be Smart that breaks down the findings for you:
If you want to learn more, you can find more information in this post from NASA.
PS: Scientists have just discovered a possibly habitable exoplanet just 4.24 light years away! This is a historic find and you should check out the article from PBS NewsHour.