How to make a Milky Way: the ultimate galactic recipe

11/11/21 • 25 min

When our ancestors looked up into the night sky, they too saw a great, glimmering band of light splitting the darkness. In Southeast Asia, people called it “the Silver River.” In Southern Africa, “the Backbone of the Night.” And in the West, around 2,500 years ago, it earned the name “the Milky Way.” Across the globe, civilizations had theories of what the band of light was and why it was there. But only recently have humans had the tools to get the full picture. Today we know the Milky Way is our galaxy: two spiral arms filled with more than 100 billion stars, all rotating around a supermassive black hole. And here on our little blue planet, we’re in the middle of it all. Dr. Alok Patel speaks with two galaxy experts to find out how scientists have built the first high-resolution, three-dimensional map of the Milky Way—and what that map reveals about the formation and future of our galactic home.

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Fusion: Can we recreate the renewable power of stars down on Earth?

The process that powers our sun was still a mystery about 100 years ago. Bit by bit, scientists have worked out that the fusion of hydrogen at a star’s core can generate enough power to keep it shining for billions of years. Now, armed with this knowledge, researchers around the world are trying to figure out if we can recreate that fusion process here on Earth. (And yes, trying to kickstart fusion—and then contain superheated plasmas that reach temperatures up to 100 million degrees Celsius—is just as hard as it sounds.) If scientists can pull it off, the payoff could be huge: A deep understanding of stellar physics could one day lead to a virtually unlimited supply of clean energy. To discover just how, Dr. Alok Patel hears from an astrophysicist and a fusion scientist.

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The hitchhiker’s guide to exoplanets and alien life

If television shows and movies are any indication, we humans spend a lot of our time subconsciously preparing for UFOs carrying maleficent aliens to descend on Earth. But should we rush to create an intergalactic battle plan? In actuality, finding otherworldly life won’t be so easy (or, hopefully, so dangerous). Already, astronomers and other scientists are using a multitude of techniques to search for planets outside our solar system and any signs of life they carry. With 4,500 exoplanets identified out of what could be hundreds of billions in our galaxy alone, one thing is becoming clear: If we find extraterrestrial life, it likely won’t be anything like Hollywood has imagined. Hearing from two exoplanet experts about the diversity of planets and life in the Milky Way, Dr. Alok Patel learns that Earth is incredibly unique—and surprisingly mundane.