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Categories: Offbeat: Paleontology and Archeology, Space: The Solar System
Published Why the day is 24 hours long: Astrophysicists reveal why Earth's day was a constant 19.5 hours for over a billion years
(via sciencedaily.com) Original source Astrophysicists have revealed how the slow and steady lengthening of Earth's day caused by the tidal pull of the moon was halted for over a billion years. They show that from approximately two billion years ago until 600 million years ago, an atmospheric tide driven by the sun countered the effect of the moon, keeping Earth's rotational rate steady and the length of day at a constant 19.5 hours. Without this billion-year pause in the slowing of our planet's rotation, our current 24-hour day would stretch to over 60 hours. The paper offers a new perspective on how global warming will affect the length of our day and validates global circulation models as a climate modelling tool.
Published Earth formed from dry, rocky building blocks
(via sciencedaily.com) Original source A new study shows that the so-called planetesimals that accreted together to form Earth must have been composed of dry, rocky materials.
Published Large sub-surface granite formation signals ancient volcanic activity on Moon's dark side
(via sciencedaily.com) Original source A large formation of granite discovered below the lunar surface likely was formed from the cooling of molten lava that fed a volcano or volcanoes that erupted early in the Moon's history -- as long as 3.5 billion years ago.
Published Apex predator of the Cambrian likely sought soft over crunchy prey
(via sciencedaily.com) Original source Biomechanical studies on the arachnid-like front 'legs' of an extinct apex predator show that the 2-foot (60-centimeter) marine animal Anomalocaris canadensis was likely much weaker than once assumed. One of the largest animals to live during the Cambrian, it was probably agile and fast, darting after soft prey in the open water rather than pursuing hard-shelled creatures on the ocean floor.
Published New image from James Webb Space Telescope reveals astonishing Saturn and its rings
(via sciencedaily.com) Original source Saturn's iconic rings seem to glow eerily in this incredible infrared picture, which also unveils unexpected features in Saturn's atmosphere. This image serves as context for an observing program that will test the telescope's capacity to detect faint moons around the planet and its bright rings. Any newly discovered moons could help scientists put together a more complete picture of the current system of Saturn, as well as its past.
Published Astrophysicists propose a new way of measuring cosmic expansion: Lensed gravitational waves
(via sciencedaily.com) Original source The universe is expanding; we've had evidence of that for about a century. But just how quickly celestial objects are receding from each other is still up for debate.
Published Gullies on Mars could have been formed by recent periods of liquid meltwater, study suggests
(via sciencedaily.com) Original source A study offers new insights into how water from melting ice could have played a recent role in the formation of ravine-like channels that cut down the sides of impact craters on Mars.
Published How urea may have been the gateway to life
(via sciencedaily.com) Original source Urea reacts extremely quickly under the conditions that existed when our planet was newly formed. This new insight furthers our understanding of how life on Earth might have begun.
Published Life after death: Astronomers find a planet that shouldn't exist
(via sciencedaily.com) Original source The star would have inflated up to 1.5 times the planet's orbital distance -- engulfing the planet in the process -- before shrinking to its current size at only one-tenth of that distance.
Published Magnetic bacteria point the way
(via sciencedaily.com) Original source Magnetotactic bacteria, which can align with the Earth's magnetic field, have been discovered in a new location. Previously observed on land and in shallow water, analysis of a hydrothermal vent has proven that they can also survive deep under the ocean. The bacteria were able to exist in an environment that was not ideal for their typical needs. Magnetotactic bacteria are of interest not only for the role they play in Earth's ecosystem, but also in the search for extraterrestrial life. Evidence of their existence can remain in rocks for billions of years. Their magnetic inclinations can also provide a record of how magnetic poles have shifted over time. This new discovery brings hope to researchers that the magnetic bacteria might be found in yet more unexpected locations, on Earth and perhaps even on Mars or beyond.
Published Newly discovered Jurassic fossils in Texas
(via sciencedaily.com) Original source Scientists have filled a major gap in the state's fossil record -- describing the first known Jurassic vertebrate fossils in Texas. The weathered bone fragments are from the limbs and backbone of a plesiosaur, an extinct marine reptile.
Published Megalodon was no cold-blooded killer
(via sciencedaily.com) Original source How the megalodon, a shark that went extinct 3.6 million years ago, stayed warm was a matter of speculation among scientists. Using an analysis of tooth fossils from the megalodon and other sharks of the same period, a study suggests the animal was able to maintain a body temperature well above the temperature of the water in which it lived. The finding could help explain why the megalodon went extinct during the Pliocene Epoch.
Published 'We're all Asgardians': New clues about the origin of complex life
(via sciencedaily.com) Original source According to a new study, eukaryotes -- complex life forms with nuclei in their cells, including all the world's plants, animals, insects and fungi -- trace their roots to a common Asgard archaean ancestor. That means eukaryotes are, in the parlance of evolutionary biologists, a 'well-nested clade' within Asgard archaea, similar to how birds are one of several groups within a larger group called dinosaurs, sharing a common ancestor.
Published Molecular filament shielded young solar system from supernova
(via sciencedaily.com) Original source Isotope ratios found in meteorites suggest that a supernova exploded nearby while the Sun and Solar System were still forming. But the blast wave from a supernova that close could have potentially destroyed the nascent Solar System. New calculations shows that a filament of molecular gas, which is the birth cocoon of the Solar System, aided the capture of the isotopes found in the meteorites, while acting as a buffer protecting the young Solar System from the nearby supernova blast.
Published Detection of an echo emitted by our Galaxy's black hole 200 years ago
(via sciencedaily.com) Original source An international team of scientists has discovered that Sagittarius A* (Sgr A*), the supermassive black hole at the centre of the Milky Way, emerged from a long period of dormancy some 200 years ago. The team, led by Frédéric Marin, a CNRS researcher at the Astronomical Strasbourg Observatory (CNRS/University of Strasbourg), has revealed the past awakening of this gigantic object, which is four million times more massive than the Sun. Their work is published in Nature on 21 June.
Published Exoplanet may reveal secrets about the edge of habitability
(via sciencedaily.com) Original source How close can a rocky planet be to a star, and still sustain water and life? A recently discovered exoplanet may be key to solving that mystery.
Published Scientists unearth 20 million years of 'hot spot' magmatism under Cocos plate
(via sciencedaily.com) Original source A team of scientists has observed past episodic intraplate magmatism and corroborated the existence of a partial melt channel at the base of the Cocos Plate. Situated 60 kilometers beneath the Pacific Ocean floor, the magma channel covers more than 100,000 square kilometers, and originated from the Galápagos Plume more than 20 million years ago, supplying melt for multiple magmatic events -- and persisting today.
Published Face of Anglo-Saxon teen VIP revealed with new evidence about her life
(via sciencedaily.com) Original source The face of a 16-year-old woman buried near Cambridge (UK) in the 7th century with an incredibly rare gold and garnet cross (the 'Trumpington Cross') has been reconstructed following analysis of her skull. The striking image is going on public display for the first time on 21st June, with new scientific evidence showing that she moved to England from Central Europe as a young girl, leading to an intriguing change in her diet.
Published These long-necked reptiles were decapitated by their predators, fossil evidence confirms
(via sciencedaily.com) Original source In the age of dinosaurs, many marine reptiles had extremely long necks compared to reptiles today. While it was clearly a successful evolutionary strategy, paleontologists have long suspected that their long-necked bodies made them vulnerable to predators. Now, after almost 200 years of continued research, direct fossil evidence confirms this scenario for the first time in the most graphic way imaginable.
Published Jupiter's moon Europa may have had a slow evolution
(via sciencedaily.com) Original source Europa may have a metamorphic origin for the ocean. While some scientists speculated this, a research team shows that if Europa indeed formed from hydrated rocks (i.e., rocks have hydrogen and oxygen), then enough of Europa's interior should get hot enough to release water directly from the hydrated rocks to form the ocean and ice shell.