A comet that wandered into our Solar System from interstellar space turns out to be older than the Sun itself. Comet 3I/ATLAS, discovered as it passed through our corner of the galaxy, has been traced back to origins that predate the formation of our Solar System from its parent nebula around 4.6 billion years ago. Nearly everything orbiting our Sun, planets, moons, asteroids scattered across the Kuiper Belt and Oort Cloud, coalesced from the same original cloud of gas and dust. This comet is different: it formed somewhere else, in a different stellar neighborhood, before taking on an interstellar journey that eventually brought it into our gravitational neighborhood. The discovery underscores how our Solar System is not a closed system but rather a space where visitors from elsewhere in the galaxy can pass through. Detecting and analyzing such visitors provides astronomers a window into stellar formation processes and compositions across different regions of the Milky Way.