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Showing posts from July 15, 2025

Earth’s Spin to Speed Up Briefly, Causing Shorter Days This Summer

Reports indicate that for three days this summer – July 9, July 22 and August 5 – Earth's rotation will speed up slightly, trimming 1.3 to 1.5 milliseconds off each day. Imperceptible in everyday life, this shift underscores how the Moon's position influences our planet's spin. For reference, the shortest day on record was July 5, 2024, lasting 1.66 milliseconds less than 24 hours. Over billions of years Earth's rotation has slowly lengthened, but recent data show speedups. Scientists say monitoring these tiny changes is important for understanding Earth's dynamics and timekeeping. Causes of Faster Spin According to timeanddate.com, the shortest-ever recorded day was on July 5, 2024, which was 1.66 milliseconds shy of 24 hours. The acceleration is largely driven by the Moon's gravity. On those dates (July 9, July 22 and August 5), the Moon will lie far north or south of Earth's equator, weakening its tidal braking on our planet's spin. As a result, Earth...