Making Stars on Earth

Nuclear fusion is the reason our sun shines. It’s the process by which two atomic nuclei fuse into one, heavier nuclei—and the process by which stars produce energy. The heart of our Sun is a vast powerhouse, where the nuclear fusion of two hydrogen atoms into one helium atom radiates huge amounts of energy. Earth’s current nuclear reactors use nuclear fission, which produces energy by splitting one atom into two. This process creates harmful radioactive waste, but nuclear fusion is cleaner, safer, and more efficient. If we could effectively build our own star here on Earth—our own celestial power plant—we would have access to unlimited clean energy, but although decades of research has created glimpses of fusion reactions such as the JET (Joint European Torus) experimental fusion reactor pictured above, we have yet to learn how to usefully harness this energy. But what we’ve managed to create so far is still amazing. In Brian Cox’s words: “Scientists have learned how to create and hold star matter—a cocktail of gases heated to 100 million degrees. For a moment, a little piece of the sun springs into life on the Earth.”

(Image Credit: Wonders of the Universe)