Recently, a study on Earth’s spin was published in the American Geophysical Union’s journal Paleoceanography and Paleoclimatology.
The study came after scientists studied a 70 million years old mollusc fossil from Oman.
Key Points
The study states that Earth spun 372 times a year 70 million years ago, compared to the current 365 times. This means the day was 23½ hours long, compared to 24 hours today.
It is important to note that the period of Earth’s orbit has remained the same. In other words, one year 70 million years ago was as long as one year today.
Today, Earth’s orbit is not exactly 365 days, but 365 days and a fraction, which is why our calendars have leap years, as a correction.
It has long been known that Earth’s spin has slowed over time.
The study states friction from ocean tides, caused by the Moon’s gravity, slows Earth’s rotation and leads to longer days. And as Earth’s spin slows, the Moon moves farther away.
The study states that the Moon's rate of retreat has changed over time.
