Subtitles section Play video Print subtitles [music] Mysteries abound in our universe, but bit by bit, we are unlocking its secrets. We now know that our galaxy contains billions of other planets – but how can we learn more about them? What traits do these exoplanets have? What are they made of? What are their environments like? How have they evolved over time? Are they habitable? And can planets lose habitability over time? Imagine we could study one of these planets up close. We find one of similar size, mass, and composition as Earth. By all accounts, this planet appears very similar to our own. We discover evidence that this world may have once had liquid water oceans and volcanoes – a setting that could have been favorable to life. But over time, something drastic happened to this environment. This planet's sun grew brighter and hotter - increasing the temperature here to the point that the oceans boiled away. And then gradually, the volcanic gasses created a thick atmosphere with clouds of sulfuric acid. That once friendly environment was gone. But all is not lost. The remnants of such a world may hold the key to understanding planetary evolution and habitability. The twist is that this isn't science fiction, this planet does exist. And if we want to learn more about the past, present, and possible future of our planet and the billions of similar exoplanets out there – this mysterious one needs more study. And it doesn't reside in some distant solar system, truth be told, it sits right next door. This planet is Venus. And the more mysteries we can unravel here, the more answers we can find out there.