For the first time, astronomers have caught a glimpse of the water snow line around a star — the point in the young star's orbiting disk of debris where snow and ice first appear. Normally, that boundary huddles too close to the star for astronomers to see it, but this particular star had a sudden burst of brightness that superheated its disk, obliterating ice further out than usual. ... A newborn star is surrounded by an orbiting pancake of gas, dust and debris — the raw materials from which its complement of alien planets will eventually form. Most stars are...
