A large group of clouds of gas and dust 400 l.y. away in the constellation Taurus. The whole group of clouds contains some 30 000 solar masses of material. One particular cloud in the group, known as Taurus Molecular Cloud 1 (TMC-1), contains only 1 solar mass of material yet is one of the coldest molecular clouds known, with a temperature of only 10 K. It contains some of the most complex interstellar molecules yet identified. The complex chemistry is thought to have developed because the cloud has remained stable for many years without forming stars.