What was happening 372 years ago

The ancient mollusk, from an extinct and wildly diverse group known as rudist clams, grew fast, laying down daily growth rings. 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. The new study also found corroborating evidence that the mollusks harbored photosynthetic symbionts that may have fueled reef-building on the scale of modern-day corals.

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 can basically look at a day 70 million years ago. 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 degrees Fahrenheit in summer and exceeding 30 degrees Celsius 86 degrees Fahrenheit in winter. The summer high temperatures likely approached the physiological limits for mollusks, de Winter said. The research study analysed a single individual that lived for over nine years in a shallow seabed in the tropics--a location which is now, million-years later, dry land in the mountains of Oman.

Torreites sanchezi mollusks look like tall pint glasses with lids shaped like bear claw pastries. The ancient mollusks had two shells, or valves, that met in a hinge, like asymmetrical clams, and grew in dense reefs, like modern oysters.

They thrived in water several degrees warmer worldwide than modern oceans. In the late Cretaceous, rudists like T. It's all due to the Northern Hemisphere being tilted farther from the sun than at any other point during the year.

As a result, the sun follows its lowest arc of the year across the sky. Get more winter solstice facts. In the early morning hours of the winter solstice day, many sky-watchers will see the first shadings of a total lunar eclipse.

The entire lunar eclipse will be best seen from North America and western South America. In most of Europe and Africa, the moon will dip below the horizon in mid-eclipse. Unlike, say, last week's Geminid meteor shower pictures , a lunar eclipse represents "one of the few times that an astronomical event is easily visible from even the heavily light polluted cities," said Raminder Singh Samra, resident astronomer at the H.

Clouds, for example, can spoil any sky-watcher's night. And the lunar eclipse will be completely invisible to observers in southern and eastern Africa, the Middle East, or southern Asia. A lunar eclipse occurs when the moon, Earth , and the sun all line up, with Earth in the middle. During the eclipse, Earth's shadow is cast onto the full moon , dimming—but not completely obscuring—its surface. Unlike solar eclipses, the lunar varieties are safe to view without any special eyewear.

Lunar eclipses occur twice a year. The previous one fell on June 26, The winter solstice lunar eclipse will be the first total eclipse of the moon in nearly three years, the last one being on February 20, , according to Singh.

See solstice pictures : fire rites, druids, and more. Around 1 a. ET Tuesday, you may notice a ghostly shading of the moon, marking the arrival of Earth's faint outer shadow, or penumbra.

Shortly after a. ET, begin looking for the first signs of a dim "bite"—Earth's shadow—advancing across the moon from the left. The total eclipse, or totality—when the entire moon is dimmed by Earth's shadow—begins at a. ET and will last a little over 70 minutes. Around a. ET, as the moon plunges into Earth's umbra—the dark center of our planet's shadow—the moon will slowly begin glowing orange.

The next total lunar eclipse will occur on June 15, , and will be best seen from southern Asia and eastern Africa. The summer high temperatures probably approached the physiological limits for mollusks, de Winter said. The species of mollusk that was studied is extinct, disappearing in the same extinction event that killed the nonavian dinosaurs 66 million years ago.

But the number of days within a year has been shortening over time because days have been growing longer. The study appeared in the journal Paleoceanography and Paleoclimatology , a publication of the American Geophysical Union. Facebook Twitter Email. Days were a half-hour shorter when dinosaurs roamed the Earth 70 million years ago.