“I am a cloud that wants to dissipate like smoke in the air but gravity wants to pull me together.”
- notes on how stars are formed
NGC 4676, Playful Mice
New SpaceTime on YouTube….
Been playing a bit of Among Us when feeling well enough. So decided to give Gwyd and Goch an Among Us look for fun.
Discovery of a new mass extinction
It’s not often a new mass extinction is identified; after all, such events were so devastating they really stand out in the fossil record.
In a new paper, published today in Science Advances, an international team has identified a major extinction of life 233 million years ago that triggered the dinosaur takeover of the world.
The crisis has been called the Carnian Pluvial Episode.
The team of 17 researchers, led by Jacopo Dal Corso of the China University of Geosciences at Wuhan and Mike Benton of the University of Bristol’s School of Earth Sciences, reviewed all the geological and palaeontological evidence and determined what had happened.
The cause was most likely massive volcanic eruptions in the Wrangellia Province of western Canada, where huge volumes of volcanic basalt was poured out and forms much of the western coast of North America.
“The eruptions peaked in the Carnian,” says Jacopo Dal Corso.
“I was studying the geochemical signature of the eruptions a few years ago and identified some massive effects on the atmosphere worldwide.
The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming”.
The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about 1 million years in all.
The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems.
The shifts in climate encouraged growth of plant life, and the expansion of modern conifer forests.
“The new floras probably provided slim pickings for the surviving herbivorous reptiles,” said Professor Mike Benton.
“I had noted a floral switch and ecological catastrophe among the herbivores back in 1983 when I completed my PhD.
We now know that dinosaurs originated some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit.
It was the sudden arid conditions after the humid episode that gave dinosaurs their chance.”
It wasn’t just dinosaurs, but also many modern groups of plants and animals also appeared at this time, including some of the first turtles, crocodiles, lizards, and the first mammals.
The Carnian Pluvial Episode also had an impact on ocean life.
It marks the start of modern-style coral reefs, as well as many of the modern groups of plankton, suggesting profound changes in the ocean chemistry and carbonate cycle.
“So far, palaeontologists had identified five "big” mass extinctions in the past 500 million yeas of the history of life,“ says Jacopo Dal Corso.
"Each of these had a profound effect on the evolution of the Earth and of life.
We have identified another great extinction event, and it evidently had a major role in helping to reset life on land and in the oceans, marking the origins of modern ecosystems.”
Paper: ‘Extinction and dawn of the modern world in the Carnian (Late Triassic)’ by J. Dal Corso and 16 others in Science Advances 6, eaba0099.
IMAGE….Summary of major extinction events through time, highlighting the new, Carnian Pluvial Episode at 233 million years ago. CREDIT D. Bonadonna/ MUSE, Trento
Astronomers capture stellar winds in unprecedented detail
Astronomers present an explanation for the mesmerising shapes of planetary nebulae. The discovery is based on an extraordinary set of observations of stellar winds around ageing stars. Contrary to common consensus, the team found that stellar winds are not spherical but have a shape similar to that of planetary nebulae. The team concludes that interaction with an accompanying star or exoplanet shapes both the stellar winds and planetary nebulae. The findings were published in Science.
Dying stars swell and cool to eventually become red giants. They produce stellar winds, flows of particles that the star expels, which causes them to lose mass. Because detailed observations were lacking, astronomers have always assumed that these winds were spherical, like the stars they surround. As the star evolves further, it heats up again and the stellar radiation causes the expanding ejected layers of stellar material to glow, forming a planetary nebula.
For centuries, astronomers were in the dark about the extraordinary variety of colourful shapes of planetary nebulae that had been observed. The nebulae all seem to have a certain symmetry but are almost never round. “The Sun - which will ultimately become a red giant - is as round as a billiard ball, so we wondered: how can such a star produce all these different shapes?” says corresponding author Leen Decin (KU Leuven).
Her team observed stellar winds around cool red giant stars with the ALMA Observatory in Chile, the largest radio telescope in the world. For the first time ever, they gathered a large, detailed collection of observations, each of them made using the exact same method. This was crucial to be able to directly compare the data and exclude biases.
What the astronomers saw, surprised them. “We noticed these winds are anything but symmetrical or round,” Professor Decin says. “Some of them are actually quite similar in shape to planetary nebulae.”
The astronomers could even identify different categories of shapes. “Some stellar winds were disk-shaped, others contained spirals, and in a third group, we identified cones.” This is a clear indication that the shapes weren’t created randomly. The team realised that other, low-mass stars or even heavy planets in the vicinity of the dying star were causing the different patterns. These companions are too small and dim to detect directly. “Just like how a spoon that you stir in a cup of coffee with some milk can create a spiral pattern, the companion sucks material towards it as it revolves around the star and shapes the stellar wind,” Decin explains.
The team put this theory into models, and indeed: the shape of the stellar winds can be explained by the companions that surround them, and the rate at which the cool evolved star is losing its mass due to the stellar wind is an important parameter. Decin: “All our observations can be explained by the fact that the stars have a companion.”
Up until now, calculations about the evolution of stars were based on the assumption that ageing Sun-like stars have stellar winds that are spherical. “Our findings change a lot. Since the complexity of stellar winds was not accounted for in the past, any previous mass-loss rate estimate of old stars could be wrong by up to a factor of 10.” The team is now doing further research to see how this might impact calculations of other crucial characteristics of stellar and galactic evolution.
The future of the Sun
The study also helps to envision what the Sun might look like when it dies in 7000 million years. “Jupiter or even Saturn - because they have such a big mass - are going to influence whether the Sun spends its last millennia at the heart of a spiral, a butterfly, or any of the other entrancing shapes we see in planetary nebulae today,” Decin notes. “Our calculations now indicate that a weak spiral will form in the stellar wind of the old dying Sun.”
“We were very excited when we explored the first images,” says co-author Miguel Montargès (KU Leuven). “Each star, which was only a number before, became an individual by itself. Now, to us, they have their own identity. This is the magic of having high-precision observations: stars are no longer just points anymore.”
The study is part of the ATOMIUM project, which aims to learn more about the physics and chemistry of old stars. “Cool ageing stars are considered to be boring, old and simple, but we now prove that they are not: they tell the story of what comes after. It took us some time to realise that stellar winds can have the shape of rose petals (see, for example, the stellar wind of R Aquilae), but, as Antoine de Saint-Exupéry said in his book Le Petit Prince: ‘C'est le temps que tu as perdu pour ta rose, qui fait ta rose si importante’ - 'It’s the time you spent on your rose that makes your rose so important’,” Decin concludes.
TOP IMAGE….The stellar wind of R Aquilae resembles the structure of rose petals. Credit L. Decin, ESO/ALMA
LOWER IMAGE….This image gallery of stellar winds around cool ageing stars shows a variety of morphologies, including disks, cones, and spirals. The blue colour represents material that is coming towards you; red is material that is moving away from you. Credit © L. Decin, ESO/ALMA
✨🌱Space themed pot for my Spacey-looking Succulents🌱✨
Should I add small ceramic pots to the shop?
✨💕Please Do Not Repost💕✨
Breaking Distant Light
Bioluminescent algae and the milky way rising over South Arm, Tasmania…I believe the ISS is also present just to the right above the clouds! [OC] via /r/spaceporn. Picture posted by /u/soetkyaw.
Plans underway for new polar ice and snow topography mission
Monitoring the cryosphere is essential to fully assess, predict and adapt to climate variability and change.
Given the importance of this fragile component of the Earth system, today ESA, along with Airbus Defence and Space and Thales Alenia Space, have signed a contract to develop the Copernicus Polar Ice and Snow Topography Altimeter mission, known as CRISTAL.
With a launch planned in 2027, the CRISTAL mission will carry, for the first time on a polar mission, a dual-frequency radar altimeter, and microwave radiometer, that will measure and monitor sea-ice thickness, overlying snow depth and ice-sheet elevations.
These data will support maritime operations in the polar oceans and contribute to a better understanding of climate processes.
CRISTAL will also support applications related to coastal and inland waters, as well as providing observations of ocean topography.
The mission will ensure the long-term continuation of radar altimetry ice elevation and topographic change records, following on from previous missions such as ESA’s Earth Explorer CryoSat mission and other heritage missions.
With a contract secured worth € 300 million, Airbus Defence and Space has been selected to develop and build the new CRISTAL mission, while Thales Alenia Space has been chosen as the prime contractor to develop its Interferometric Radar Altimeter for Ice and Snow (IRIS).
ESA’s Director of Earth Observation Programmes, Josef Aschbacher, says, “I am extremely pleased to have the contract signed so we can continue the development of this crucial mission.
It will be critical in monitoring climate indicators, including the variability of Arctic sea ice, and ice sheet and ice cap melting.”
The contract for CRISTAL is the second out of the six new high-priority candidate missions to be signed – after the Copernicus Carbon Dioxide Monitoring mission (CO2M) in late-July.
The CRISTAL mission is part of the expansion of the Copernicus Space Component programme of ESA, in partnership with the European Commission.
The European Copernicus flagship programme provides Earth observation and in situ data, as well as a broad range of services for environmental monitoring and protection, climate monitoring and natural disaster assessment to improve the quality of life of European citizens.
Venus In A New Light by NASA’s Marshall Space Flight Center
i was doing wires!
Hernández - QUERO (prod. KEEPOUT)
I’m not alive
My first ever picture of Saturn 🪐 via /r/spaceporn. Picture posted by /u/NizegamexD.