A new study published Monday suggests that in 2009, the Earth’s inner core slowed its rotation to move in sync with the rest of the planet. The inner core is solid, but floats around in a liquid outer core. Geologists believe the energy created by our inner core protects us from the most damaging forms of cosmic radiation from our nearest star — the sun. Prior to 2009, seismic waves traveled at different rates through Earth’s inner core, but this pattern vanished suddenly 14 years ago. Research published in 2022 argued that the inner core reverses direction every three-ish years.

Source: Washington Post January 24, 2023 15:41 UTC