A new study suggests that a tiny, icy world beyond Pluto harbors a thin, delicate atmosphere that may have been created by volcanic eruptions or a comet strike. Just 300 miles (500 kilometers) or so ... CAPE CANAVERAL, Fla. (AP) — A new study suggests that a tiny, icy world beyond Pluto harbors a thin, delicate atmosphere that may have been created by volcanic eruptions or a comet strike. Just 300 miles (500 kilometers) or so across, this mini Pluto... [2521 chars]