The sight of a snowfall can thrill children, but the
first-ever snow line seen around a distant star gives astronomers an even
greater thrill because of what it reveals about the formation of planets and
our Solar System's history.
Astronomers using the new Atacama Large
Millimeter/submillimeter Array (ALMA) telescope have taken the first-ever image
of a snow line in an infant solar system. This frosty landmark is thought to
play an essential role in the formation and chemical make-up of planets around
a young star.