In a startling announcement, researchers at NASA’s Jet Propulsion Laboratory have confirmed that Earth’s rotation is accelerating, setting the stage for the shortest day in recorded history—expected within weeks. Data from the International Earth Rotation and Reference Systems Service (IERS) reveal a steady trend toward faster spins, shaving milliseconds off each 24-hour cycle.
@NASA “Earth’s rotation is unexpectedly speeding up—be ready for a record-breaking short day soon.” Tweet by NASA JPL
Typically, the length of a day varies by fractions of a millisecond due to factors like tides and atmospheric winds. But in the past six months, IERS scientists have recorded a cumulative gain of 1.5 milliseconds, according to a BBC News report. That means the upcoming day could be more than 1.6 milliseconds shorter than the current record of 1.59 milliseconds set in 2020.
@BBCScience “Earth’s day could be shortest ever—researchers track unprecedented acceleration.” BBC Science tweet
Dr. Eleanor Smith, lead author of the study published in Scientific American, explained that “changes in the distribution of Earth’s mass—meltwater shifts, glacial rebound, and even large‐scale weather patterns—can alter rotational inertia, speeding up the spin.” She noted that satellite observations from the National Oceanic and Atmospheric Administration corroborate these mass‐redistribution effects.
@NOAA “Satellite data shows polar ice melt and water redistribution driving subtle Earth spin-ups.” NOAA climate analysis
The implications extend beyond calendar trivia. Global timekeeping systems rely on Coordinated Universal Time (UTC), which occasionally adds “leap seconds” to keep atomic clocks in sync with Earth’s rotation. With days growing shorter, the IERS may propose a “negative leap second” for the first time—effectively skipping one second to realign clocks, as detailed by ScienceAlert.
@ScienceAlert “Brace for a negative leap second—timekeepers scramble as Earth outruns our clocks.” Read more
International time bureaus met last month at the Bureau International des Poids et Mesures (BIPM) to discuss this unprecedented scenario. “We’ve only ever added seconds,” said BIPM director Dr. Lucas Nguyen in his opening address. “Reversing the process raises technical challenges for navigation, communications, and even stock‐market timestamps.”
@IERS “First negative leap second on the table—experts evaluate global impact.” IERS update
A negative leap second would require software updates in systems worldwide. Airlines, power grids, and financial markets use atomic‐time protocols that assume occasional positive leaps, warns cybersecurity consultant Maya Patel in a Forbes analysis. “Failure to patch could lead to data‐center crashes or trading errors,” she cautions.
Meanwhile, geophysicists point to long‐term trends: since 2020, Earth has gained roughly 28 milliseconds of rotation speed. The U.S. Geological Survey notes that gradual recovery of Earth’s crust—known as post‐glacial rebound—continues redistributing mass away from poles, subtly spinning the planet faster, as modeled in their geodynamics database.
@USGSgov “Crustal rebound from ice loss is measurably speeding up Earth’s rotation.” USGS geodynamics tweet
Some scientists speculate that volcanic activity could also play a role. The Smithsonian Global Volcanism Program reports a slight uptick in major eruptions over the past two years, each event ejecting mass into the atmosphere and redistributing weight on the surface—another contributor to the planet’s changing moment of inertia.
@SmithsonianVolc “Volcanic mass ejections can tweak rotational speed—an overlooked factor in Earth’s spin.” Volcanism insight
For the general public, the record‐short day will pass unnoticed—no clocks stop or reverse; instead, atomic‐time servers will silently adjust. But the phenomenon serves as a stark reminder that our planet’s dynamics are in flux. “We often think of Earth as fixed,” Dr. Smith reflects, “but it’s a living, breathing system, responding to climate change and tectonic processes in measurable ways.”
This convergence of climatology, geology, and timekeeping underscores the interconnectedness of Earth systems. As humanity grapples with global warming, melting ice caps, and rising seas, even the length of our days shifts—literally—under our feet.
