On December 5, scientists at the Lawrence Livermore National Laboratory (LLNL) in California created a nuclear fusion reaction that produced three megajoules of energy. It was only enough energy to boil a kettle of water.

So why is the science world so excited?

Because, for the first time, a fusion reaction has produced more energy than it took to create it.

Star power

The Sun and other stars generate massive amounts of energy through nuclear fusion. Our Sun creates so much energy that it heats our planet and lights our skies, 150 million kilometres away.