Within the Milky Way, there are an estimated 200 to 400 billion stars, all of which orbit around the center of our galaxy in a coordinated cosmic dance. As they orbit, stars in the galactic disk (where our Sun is located) periodically shuffle about and get closer to one another. At times, this can have a drastic effect on the star that experience a close encounter, disrupting their systems and causing planets to be ejected.
Knowing when stars will make a close encounter with our Solar System, and how it might shake-up objects within it, is therefore a concern to astronomers. Using data collected by the Gaia Observatory, two researchers with the Russian Academy of Sciences (RAS) determined that a handful of stars will be making close passes by our Solar System in the future, one of which will stray pretty close!
In 2013, the European Space Agency (ESA) deployed the Gaia mission to space, a next-generation observatory that will spend the next five years gathering data on the positions, distances, and proper motions of stars. The resulting data will be used to construct the largest 3D space catalog ever, totaling 1 billion stars, planets, comets, asteroids, quasars, and other celestial objects.
Since the mission began, the ESA has issued three early releases of Gaia data, each of which has led to new research findings and more detailed maps of our galaxy. Based on the third release of mission data, known as Early Data Release 3 (Gaia EDR3), astronomers have created a map of the entire sky that includes updated data on celestial objects and manages to capture the total brightness and color of stars in our galaxy.