MOSCOW, Jan 14 — The acceleration of the Earth’s rotation is expected to make 2021 shorter than the previous year and possibly prompt a subtraction of 1 second from Coordinated Universal Time (UTC), Sputnik has learned from the Russian Metrological Institute of Technical Physics and Radio Engineering, which includes Russia’s time signal authority.
On the turn of 2021, media frequented quoting scientists as saying that the Earth rotated progressively faster, making a standard day shorter than 24 hours. According to reports, 2020 contained 28 shortest days in history (since the start of metrological observations in 1960), and July 19 was recorded 1.4 milliseconds shorter than normal. The trend is reportedly expected to continue in the coming year.
“Indeed, the preliminary forecast is yes (the day will become shorter), but only if the current pace of acceleration of the Earth’s rotation is preserved,” a spokesperson for the Russian institute said.
For decades, the Earth rotated around its axis faster than in 24 hours (one atomic day), and scientists used to add 1 second to UTC every 18 months on average to balance the difference. The rotational period of Earth around its axis is called a stellar day, or UT1.
“Over the past four years, the difference between the stellar day and the atomic day almost vanished, so there was no need to add extra seconds to UTC. If the acceleration of the Earth’s rotation continues at the same pace, we may end up needing not to add, but subtract seconds from UTC,” the spokesperson said.
Since 1972, a total of 27 seconds were added to UTC to balance the universal time. The first balancing second was added on July 1, 1972 and the last one overnight January 1, 2017.
— Bernama
