Cosmic frost! Astronomers have discovered a snowy region in a far-off baby solar system, 175 light years away from the Earth. The snow line, located in the disc around the Sun-like star TW Hydrae, has been imaged in a far-off infant solar system for the very first time. The discovery promises to bring out more about the formation of planets and comets, the factors that decide their composition, and the history of the Solar System. Astronomers using the Atacama LargeMillimetre/submillimetre Array imaged the snow line in an infant solar system. On Earth, snow lines form at high altitudes where falling temperatures turn the moisture in the air into snow. This line is clearly visible on a mountain, where the snow-capped summit ends and the rocky face begins. The snow lines around young stars form in a similar way, in the distant, colder reaches of the dusty discs from which solar systems form. Starting from the star and moving outwards, water is the first to freeze, forming the first snow line. Further out from the star, as temperatures drop, more exotic molecules can freeze and turn to snow, such as carbon dioxide, methane, and carbon monoxide.
