A New Study on Earth | 16 Mar 2020

Why in News

  • 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.

Source: Indian Express