Around the Milky Way in 230 Million Years: The Sun's Orbit Isn't a Do-Over
Space Daily explains that the Sun's orbit around the Milky Way takes roughly 225–250 million years (230 Myr is the common figure), but this isn't precise since the period depends on position in the galaxy and Gaia data have nudged estimates downward. One galactic year ago places Earth in the Late Triassic (about 230–233 million years ago), when the first dinosaurs appeared. The idea of returning to the exact same spot is misleading because differential rotation, moving spiral arms, and the Sun's vertical oscillation change the local environment over time. A plane-crossing extinction link remains unproven, so the galactic-year picture is a useful though imprecise scale of cosmic time.