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Categories: Paleontology: Climate, Space: Structures and Features
Published Vivid portrait of interacting galaxies marks Webb's second anniversary
(via sciencedaily.com) Original source Two for two! A duo of interacting galaxies commemorates the second science anniversary of NASA's James Webb Space Telescope, which takes constant observations, including images and highly detailed data known as spectra. Its operations have led to a 'parade' of discoveries by astronomers around the world.
Published How the 'heart and lungs' of a galaxy extend its life
(via sciencedaily.com) Original source Galaxies avoid an early death because they have a 'heart and lungs' which effectively regulate their 'breathing' and prevent them growing out of control, a new study suggests. If they didn't, the universe would have aged much faster than it has and all we would see today is huge 'zombie' galaxies teeming with dead and dying stars. That's according to a new study that investigates one of the great mysteries of the Universe -- why galaxies are not as large as astronomers would expect.
Published Scientific definition of a planet says it must orbit our sun; A new proposal would change that
(via sciencedaily.com) Original source The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects near its orbit around the sun. Scientists now recognize the existence of thousands of planets, but the IAU definition applies only to those within our solar system. The new proposed definition specifies that the body may orbit one or more stars, brown dwarfs or stellar remnants and sets mass limits that should apply to planets everywhere.
Published Unveiling 1,200 years of human occupation in Canada's Arctic
(via sciencedaily.com) Original source A recent study provides new insights into ancient cultures in Canada's Arctic, focusing on Paleo-Inuit and Thule-Inuit peoples over thousands of years. Researchers detected human presence and settlements on Somerset Island, Nunavut, by analyzing sediment samples.
Published Dark matter in dwarf galaxy tracked using stellar motions
(via sciencedaily.com) Original source The qualities and behavior of dark matter, the invisible 'glue' of the universe, continue to be shrouded in mystery. Though galaxies are mostly made of dark matter, understanding how it is distributed within a galaxy offers clues to what this substance is, and how it's relevant to a galaxy's evolution.
Published Mars likely had cold and icy past, new study finds
(via sciencedaily.com) Original source The question of whether Mars ever supported life has captivated the imagination of scientists and the public for decades. Central to the discovery is gaining insight into the past climate of Earth's neighbor: was the planet warm and wet, with seas and rivers much like those found on our own planet? Or was it frigid and icy, and therefore potentially less prone to supporting life as we know it? A new study finds evidence to support the latter by identifying similarities between soils found on Mars and those of Canada's Newfoundland, a cold subarctic climate.
Published The origins of dark comets
(via sciencedaily.com) Original source Up to 60% of near-Earth objects could be dark comets, mysterious asteroids that orbit the sun in our solar system that likely contain or previously contained ice and could have been one route for delivering water to Earth, according to a new study.
Published Strong evidence for intermediate-mass black hole in Omega Centauri
(via sciencedaily.com) Original source Most known black holes are either extremely massive, like the supermassive black holes that lie at the cores of large galaxies, or relatively lightweight, with a mass of under 100 times that of the Sun. Intermediate-mass black holes (IMBHs) are scarce, however, and are considered rare 'missing links' in black hole evolution.
Published Found with Webb: A potentially habitable icy world
(via sciencedaily.com) Original source A international team of astronomers has made an exciting discovery about the temperate exoplanet LHS 1140 b: it could be a promising 'super-Earth' covered in ice or water.
Published Building materials for water-rich planets in the early solar system
(via sciencedaily.com) Original source Age data for certain classes of meteorite have made it possible to gain new findings on the origin of small water-rich astronomical bodies in the early solar system. These planetesimals continually supplied building materials for planets -- also for the Earth, whose original material contained little water. The Earth received its actual water through planetesimals, which emerged at low temperatures in the outer solar system, as shown by computational models carried out by an international research teach with participation by earth scientists.
Published Stench of a gas giant? Nearby exoplanet reeks of rotten eggs, and that's a good thing
(via sciencedaily.com) Original source An exoplanet infamous for its deadly weather has been hiding another bizarre feature -- it reeks of rotten eggs, according to a new study of data from the James Webb Space Telescope.
Published Fresh wind blows from historical supernova
(via sciencedaily.com) Original source A mysterious remnant from a rare type of supernova recorded in 1181 has been explained for the first time. Two white dwarf stars collided, creating a temporary 'guest star,' now labeled supernova (SN) 1181, which was recorded in historical documents in Japan and elsewhere in Asia. However, after the star dimmed, its location and structure remained a mystery until a team pinpointed its location in 2021. Now, through computer modeling and observational analysis, researchers have recreated the structure of the remnant white dwarf, a rare occurrence, explaining its double shock formation. They also discovered that high-speed stellar winds may have started blowing from its surface within just the past 20-30 years. This finding improves our understanding of the diversity of supernova explosions, and highlights the benefits of interdisciplinary research, combining history with modern astronomy to enable new discoveries about our galaxy.
Published The dawn of the Antarctic ice sheets
(via sciencedaily.com) Original source In recent years global warming has left its mark on the Antarctic ice sheets. The 'eternal' ice in Antarctica is melting faster than previously assumed, particularly in West Antarctica more than East Antarctica. The root for this could lie in its formation, as an international research team has now discovered: sediment samples from drill cores combined with complex climate and ice-sheet modelling show that permanent glaciation of Antarctica began around 34 million years ago -- but did not encompass the entire continent as previously assumed, but rather was confined to the eastern region of the continent (East Antarctica).
Published Mighty floods of the Nile River during warmer and wetter climates
(via sciencedaily.com) Original source Global warming as well as recent droughts and floods threaten large populations along the Nile Valley. Sediment cores off the Nile mouth reveal insights into the effects and causes of heavy rainfall episodes about 9,000 years ago. That will help to prepare for weather extremes in a changing climate.
Published The evidence is mounting: humans were responsible for the extinction of large mammals
(via sciencedaily.com) Original source Human hunting, not climate change, played a decisive role in the extinction of large mammals over the last 50,000 years. This conclusion comes from researchers who reviewed over 300 scientific articles from many different fields of research.
Published Investigating newly discovered hydrothermal vents at depths of 3,000 meters off Svalbard
(via sciencedaily.com) Original source Hydrothermal vents can be found around the world at the junctions of drifting tectonic plates. But there are many hydrothermal fields still to be discovered. During a 2022 expedition of the MARIA S. MERIAN, the first field of hydrothermal vents on the 500-kilometer-long Knipovich Ridge off the coast of Svalbard was discovered.
Published Tiny bright objects discovered at dawn of universe baffle scientists
(via sciencedaily.com) Original source A recent discovery by NASA's James Webb Space Telescope (JWST) confirmed that luminous, very red objects previously detected in the early universe upend conventional thinking about the origins and evolution of galaxies and their supermassive black holes.
Published Too many missing satellite galaxies found
(via sciencedaily.com) Original source Bringing us one step closer to solving the 'missing satellites problem,' researchers have discovered two new satellite galaxies.
Published The density difference of sub-Neptunes finally deciphered
(via sciencedaily.com) Original source The majority of stars in our galaxy are home to planets. The most abundant are the sub-Neptunes, planets between the size of Earth and Neptune. Calculating their density poses a problem for scientists: depending on the method used to measure their mass, two populations are highlighted, the dense and the less dense. Is this due to an observational bias or the physical existence of two distinct populations of sub-Neptunes? Recent work argues for the latter.
Published Precision instrument bolsters efforts to find elusive dark energy
(via sciencedaily.com) Original source Dark energy -- a mysterious force pushing the universe apart at an ever-increasing rate -- was discovered 26 years ago, and ever since, scientists have been searching for a new and exotic particle causing the expansion. Physicists combined an optical lattice with an atom interferometer to hold atoms in place for up to 70 seconds -- a record for an atom interferometer -- allowing them to more precisely test for deviations from the accepted theory of gravity that could be caused by dark energy particles such as chameleons or symmetrons. Though they detected no anomalies, they're improving the experiment to perform more sensitive tests of gravity, including whether gravity is quantized.