A unique coin for a unique phenomenon. Concave on one side and convex on the other, The Black Hole illustrates the funnel shape of these regions of spacetime where gravity is so strong that nothing can escape from them. One way of envisaging a black hole is as a vortex that draws in everything in its immediate proximity. Once beyond the point of no return – known as the ‘event horizon’ – the ‘singularity’ awaits at the centre. Stephen Hawking and Roger Penrose showed that this is a place where space-time curvature is infinite.

Is there anybody out there or is all life in the universe limited to our tiny ‘third rock from the sun’? And if we manage to establish contact with extraterrestrials, will it be love at first sight or a match made in hell? These and other eternal questions are explored on Extraterrestrial Life, the 2022 edition of our ever-popular Silver Niobium coin.

The second coin in the Language of Flowers series is dedicated to a plant that divides public opinion. For some the dandelion is just an annoying weed, while for others it is the most underappreciated of plants. Whichever side of the debate you are on, the dandelion is undoubtedly one of the most joyful signs that winter is over and spring has arrived.