Gliese 436b, or GJ 436b, is a Neptune-sized exoplanet orbiting a red dwarf 33 light-years away. Ultraviolet light from the red dwarf (top left) is slowly evaporating the planet's atmosphere. The gas freed, mainly hydrogen, curves away from both planet and star to form a vast, comet-like tail. Astronomers estimate that the planet has lost a total of ten per cent of its original atmosphere, and its mass continues to shrink at a rate of 1000 tones every second. However, this only amounts to around 0.1 per cent of the star's total mass lost every billion years or so. The planet is not in danger of being evaporate away to oblivion.