The orbits of long-period comets suggest a star passed by our Sun and caused some havoc we're still seeing. Hale-Bopp, the Great Comet of 1997, is a very famous long-period comet. Image Credit: ESO/E. Slawik ================================================================= The closest star to the Sun is Proxima Centauri, about 4.2 light-years away. This has not always been the case, as all stars in the galaxies move about. Observations suggest that just 2.5 million years ago, there was a star that passed very close to the Solar System, and this passage might still have consequences we can see today. Data from the ESA Gaia...