Earth’s Passage Through The Galaxy Might Be Written In Its Rocks

The composition of crystals in volcanic rocks changes with their ages in ways that correlate with the Solar System’s movements around the Milky Way, scientists have reported. If the relationship is a real one, the findings would help us understand both our planet and our galaxy better, and prove a link between the two. The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.

The Sun orbits the center of the Milky Way at around 240 kilometers (149 miles) per second. The spiral arms that give galaxies like our own their structure also rotate, but more slowly, at an estimated 210 kilometers (130 miles) per second at the Sun’s distance from the center. Consequently, the Sun sometimes catches up with a spiral arm and passes through it. We don’t kn