Astronomers have spotted something surprising in the far outer Solar System—a faint, short-lived atmosphere clinging to a tiny icy world that shouldn’t be able to hold one at all. The object, called 2002 XV93, is far smaller than Pluto, yet observations during a rare stellar alignment revealed i ts presence through a subtle dimming of starlight. Even more puzzling, calculations suggest this atmosphere should vanish within about 1,000 years unless it’s constantly being replenished. ...read more read less