This image from the Wide Field Imager attached to the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory shows the spectacular globular star cluster Messier 4. This great ball of ancient stars is one of the closest of such stellar systems to the Earth. New observations with ESO's Very Large Telescope have revealed that one star — marked on this picture — has much more lithium than the other stars in the cluster that have been studied. The source of this lithium is mysterious. Normally this element is gradually destroyed over the billions of years of a star's life.