While most celestial events have a duration measured in thousands, if not millions, of years, some are of much shorter duration and risk being missed by conventional astronomy. As a result, the Vanishing & Appearing Sources during a Century of Observations (VASCO) project has been set up to search for fleeting astronomical events, particularly stars that vanish. Today, astronomers’ view of the sky is cluttered with satellites and debris from over 60 years of launches, all of which could potentially produce glints that might be mistaken for an intriguing phenomenon. Rather than try and do live observation and then filter these out, VASCO has opted to start by using historical data from before the mid-1950s, when there would have been no human-made objects in orbit to confuse matters.
