In the build-up to the Christmas Lectures in 2012, the Royal Institution published a new video for every day of advent revealing the elements that really excite and inspire people. From the floor of the Science Museum in London, Roger Highfield explains why the scarcity of his favourite element should concern us all. Roger describes to work of Norman Lokier, who found that the spectral signature from the sun suggested there was more to the sun than just hydrogen. Although abundant in the sun, helium is rare on Earth. It is also very useful as part of breathing gases for new born babies and for making super-conducting magnets for brain scanners.