Heard about 372 days in a year on earth? It's real
New Delhi : There was a time when the Earth used to rotate faster than it does these days, resulting in 372 rotations per year, compared to the current 365. This means that the day used to last for only 23 and a half hour.
This is from the time when dinosaurs used to live on earth.
The findings from a new study of fossil mollusk shells from the Late Cretaceous were published in AGU’s journal Paleoceanography and Paleoclimatology.
The study used lasers to sample minute slices of shell and count the growth rings more accurately than human researchers with microscopes. The growth rings allowed the researchers to determine the number of days in a year and more accurately calculate the length of a day 70 million years ago.
The new measurement informs models of how the Moon formed and how close to Earth it has been over the 4.5-billion-year history of the Earth-Moon gravitational dance.
The high resolution obtained in the new study combined with the fast growth rate of the ancient bivalves revealed unprecedented detail about how the animal lived and the water conditions it grew in, down to a fraction of a day.
“We have about four to five data points per day, and this is something that you almost never get in geological history. We can basically look at a day 70 million years ago. It’s pretty amazing,” said Niels de Winter, the lead author of the study.
Climate reconstructions of the deep past typically describe long-term changes that occur on the scale of tens of thousands of years. Studies like this one give a glimpse of change on the timescale of living things and have the potential to bridge the gap between climate and weather models.
Chemical analysis of the shell indicates ocean temperatures were warmer in the Late Cretaceous than previously appreciated, reaching 40 degrees Celsius in summer and exceeding 30 degrees Celsius in winter. The summer high temperatures likely approached the physiological limits for mollusks, de Winter said.
“The high fidelity of this data-set has allowed the authors to draw two particularly interesting inferences that help to sharpen our understanding of both Cretaceous astrochronology and rudist palaeobiology,” said Peter Skelton, a rudist expert.
(Input from agency)