Over the next few months, the Earth will spin much faster – so fast that some days will become shorter.

(Image credit: Francesco Carta Carta/Getty Images)

The Earth is expected to spin faster in the coming weeks, causing some of our days to be unusually short. On July 9, July 22, and August 5, the position of the Moon is expected to affect the Earth's rotation, causing each day to be 1.3 to 1.51 milliseconds shorter than normal.

A day on Earth is the length of time it takes for the planet to complete one full rotation on its axis—about 86,400 seconds, or 24 hours. However, many factors affect the Earth's rotation, including the positions of the Sun and Moon, changes in the Earth's magnetic field, and the distribution of mass across the planet.

Since our planet's formation, its rotation has been slowing, lengthening our days. Scientists have found that about 1-2 billion years ago, a day on Earth lasted only 19 hours. This is probably due to the Moon being closer to the planet, which increased its gravitational pull and accelerated the Earth's rotation.