On January 1, researchers at the Hefei Institutes of Physical Science at the Chinese Academy of Sciences published a wild new study in the journal Science Advances. In it, the team details the way they used EAST — which has memorably been dubbed China’s “artificial sun” — to achieve a plasma density far higher than previous limits. Nuclear fusion is the process by which two atomic nuclei combine to form a single, heavier nucleus, resulting in a huge release of energy. Because of its potential to produce limitless clean energy, scientists the world over have sought ways to use nuclear fusion as a viable power source. Scientists also manually pump extra energy into the plasma as it heats, allowing an even rise in density.