A rare comet discovered by NASA scientists will be visible using just binoculars to skywatchers on Earth this week for the first time, before the object heads back into outer reaches of the solar system for an orbit lasting thousands of years. The comet, C/2016 U1 NEOWISE, “has a good chance of becoming visible through a good pair of binoculars, although we can’t be sure because a comet’s brightness is notoriously unpredictable,” said Paul Chodas, manager of NASA’s Centre for Near-Earth Object Studies at the Jet Propulsion Laboratory in the US.