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How long did it take to establish the water content within Jupiter’s Galilean moons, Io and Europa? This is what a recent study published in The Astrophysical Journal hopes to address as a team of scientists from the United States and France investigated the intricate processes responsible for the formation and evolution of Io and Europa. This study has the potential to help scientists better understand the formation and evolution of two of the most unique moons in the solar system, as Io and Europa are known as the most volcanically active body in the solar system and an ocean world estimated to contain twice the volume of Earth’s oceans, respectively.

Excavations at an opencast mine in Greece have uncovered two wooden objects more than 400,000 years old that appear to have been fashioned as tools by an unknown species of ancient human

Icy comets contain common crystals that can only be formed in extreme heat. But comets reside in the frigid outer reaches of the Solar System. How did these materials form, and how did they find their way into the Solar System's cold fringes?

For years, scientists noticed that magnetic fields could improve steel, but no one knew exactly why. New simulations reveal that magnetism changes how iron atoms behave, making it harder for carbon atoms to slip through the metal. This slows diffusion at the atomic level and alters steel’s internal structure. The insight could lead to more efficient, lower-energy ways to make stronger steel.

A woman's fertility can be partly gauged by levels of a hormone that reflects how many eggs she has. Now, scientists have built a strip that changes colour according to levels of this hormone, which is present in period blood, into a menstrual pad

JWST has created a map of dark matter that is twice as good as anything we have had before, and it may help unravel some of the deepest mysteries of the universe

The way time ticks forward in our universe has long stumped physicists. Now, a new set of tools from entangled atoms to black holes promises to reveal time’s true nature

When materials become just one atom thick, melting no longer follows the familiar rules. Instead of jumping straight from solid to liquid, an unusual in-between state emerges, where atomic positions loosen like a liquid but still keep some solid-like order. Scientists at the University of Vienna have now captured this elusive “hexatic” phase in real time by filming an ultra-thin silver iodide crystal as it melted inside a protective graphene sandwich.

Water exists across Mars in underground ice, soil moisture, and atmospheric vapour, yet most of it remains frustratingly beyond practical reach for future explorers. A new comparative study from the University of Strathclyde evaluates the technologies that could extract this vital resource from various Martian sources, assessing each method's energy demands, scalability, and suitability for the Red Planet's harsh conditions.

Stars change in brightness for all kinds of reasons, but all of them are interesting to astronomers at some level. So imagine their excitement when a star known as J0705+0612 (or, perhaps more politically incorrectly, ASASSN-24fw) dropped to around 2.5% of its original brightness for 8.5 months. Two new papers - one from Nadia Zakamska and her team at the Gemini Telescope South and one from Raquel Forés-Toribio at Ohio State and her co-authors - examine this star and have come to the same conclusion - it’s likely being caused by a circumsecondary disk.

Thousands of pieces of abandoned spacecraft orbit Earth, and when gravity finally pulls them down, authorities rarely know exactly where they'll land. Now researchers at Johns Hopkins University have demonstrated a clever solution. Surprisingly they have found using earthquake detecting seismometers they can track falling space debris in real time by listening for the sonic booms it produces. The technique successfully traced a Chinese spacecraft module as it streaked across California at Mach 25-30, revealing its actual trajectory lay 25 miles north of predictions, a significant improvement that could help authorities quickly locate potentially toxic debris and protect people from contamination.

New research from the International Space Station reveals that in near weightless conditions, both bacteriophages and their *E. coli* hosts mutate in ways not seen on Earth. This unexpected finding not only deepens our understanding of how microbial life adapts to extreme environments but has already yielded practical benefits. Some of the mutations discovered in space dwelling viruses led researchers to create superior viruses that specifically infect and kill bacteria, capable of fighting drug resistant bacterial infections back on Earth.

Astronomers may have finally cracked one of the universe’s biggest mysteries: how black holes grew so enormous so fast after the Big Bang. New simulations show that early, chaotic galaxies created perfect conditions for small “baby” black holes to go on extreme growth spurts, devouring gas at astonishing rates. These feeding frenzies allowed modest black holes—once thought too puny to matter—to balloon into monsters tens of thousands of times the Sun’s mass.

As we continue the search for life outside of the Earth, it helps if we have a clear picture of where life might be. This is all a probability game, but that’s the point – to maximize the chance of finding the biosignatures of life. One limitation of this search, however, is that we have only one example of life and a living ecosystem – Earth. Life may take many different forms and therefore exist in what we would consider exotic environments.

That aside, it seems a good bet that life is more likely in locations where liquid water is possible, and therefore liquid water is a reasonable marker for habitability. When we talk about the habitable zone of stars, that is what we are talking about – the distance from the star where it is possible for liquid water to exist on the surface of planets. There are more variables than just the temperature of the star, however. The composition of the atmosphere also matters. High concentrations of CO2, for example, extend the habitable zone outward. There is therefore a conservative habitable zone, and then a more generous one allowing for compensating factors.

A new paper wishes to extend the conservative habitable zone further, specifically around M and K class dwarfs. K-dwarfs, or orange stars, are likely already the best candidates for life. They are bright and hot enough to support liquid water and photosynthesis, they emit less harmful radiation than red (M) dwarfs, and live a relatively long time, 15-70 billion years. They also comprise about 12% of all main sequence stars. Yellow stars like our sun are also good for life, but have a shorter lifespan (10 billion years) and make up only about 6% of main sequence stars.

There has been a lot of speculation about the habitability of red dwarfs, mostly because they make up about 70% of the stars in the Milky Way. Therefore they dramatically change the number of star systems that are candidates for life. Most of the time that you see a headline about a new study increasing or decreased the possibility of life in the galaxy, it’s a good bet it’s about red dwarf stars. Research has gone back and forth about this question, but overall I think the probability is quite low.

The biggest problem with red dwarfs is that they emit a lot of radiation, enough to blast the atmosphere of any planet in the habitable zone away. They do settle down when they get older, however. This means if a planet wanders into the inner stellar system after the star has calmed down, it may keep its atmosphere. Or a planet may reconstitute its atmosphere later in life. But this this means far fewer candidates, and these events are less likely.

Another recent paper also was pretty down of red dwarf life. The researchers calculate that while the light from red dwarfs was enough to support photosynthesis, it is not enough to support complex life. So if there were life on planets around red dwarfs, they would likely only be microbes. That’s still exciting, but, you know.

The new paper is about another feather of red dwarf planets in the habitable zone that is also problematic. In order to be close enough to be hot enough for liquid water, a planet would also likely be tidally locked. This means it would show the same face to the sun at all times, with the near side boiling and the far side freezing. A lot of attention is therefore paid to the terminus, the zone around the middle between too hot and too cold that is just right. But would this be enough to support life, and what would conditions be like there? What the new paper explores is the heat distribution on such planets. They find that heat could travel from the near side to the far side in sufficient amounts to allow for liquid water, even on the far side of the planet.

What this does is extend the habitable zone inward, closer to the star, where it is too hot on the near side and perhaps even in the terminus, but, they argue, could be habitable on the far side of the tidally locked planet.

They also argue that the conservative habitable zone may be extended outward, because there could be liquid water beneath an entirely frozen surface. This did not sound like news to me, however – because of Europa and Enceladus. We already know that icy worlds outside the conservative habitable zone can contain liquid water beneath the surface. On these worlds like would need to be mostly chemosynthetic, deriving its energy from chemical reactions rather than sunlight.

While the paper is interesting, it seems like a tweak to our existing models. I also don’t think (unlike as some flashy headlines imply) that this has a significant effect on the probability of life and therefore the amount of life in the galaxy. It basically means there may be some outlier planets that manage to have life despite being outside a conservative habitable zone. In any case, we should not expect any civilizations on these worlds. At most we might find some extremophile microbes.

Another way to look at this is (again, since we are playing the probability game), every time we identify a challenge to habitability, even if it can be theoretically overcome, the number of potential worlds that have overcome it is reduced. So now, in order to have life on a planet around an M-dwarf, we need for it to have migrated in later in life, or reconstituted an atmosphere, be able to eke out photosynthesis with low energy light, and hunker down in the liminal spaces between hot and frozen death. Such planets also likely need a strong magnetic field to protect from even the later-stage radiation from M-dwarfs.

Sure, we may find such life. But it still means that 70% of the stars in our galaxy are poor candidates for life, and at most may host some microbes. Orange stars, meanwhile, are a much better candidate. They are probably the sweet spot for life.

The post Rethinking the Habitable Zone first appeared on NeuroLogica Blog.

Last week was a hellscape for vaccines, with a RICO lawsuit against the AAP and the newly antivax CDC coming for your HPV and polio vaccines.

The post RFK Jr. is definitely coming for your vaccines (part 7): What, me worry (about polio and HPV)? first appeared on Science-Based Medicine.

Webb’s latest image of the Helix Nebula reveals a dramatic close-up of a dying star shedding its outer layers. The detailed view highlights glowing knots of gas shaped by fast-moving stellar winds colliding with older material. Changes in color trace a shift from scorching hot gas near the center to cooler regions farther out. The scene captures how stellar death helps supply the building blocks for future worlds.

Researchers have demonstrated that quantum entanglement can link atoms across space to improve measurement accuracy. By splitting an entangled group of atoms into separate clouds, they were able to measure electromagnetic fields more precisely than before. The technique takes advantage of quantum connections acting at a distance. It could enhance tools such as atomic clocks and gravity sensors.

Researchers have demonstrated that quantum entanglement can link atoms across space to improve measurement accuracy. By splitting an entangled group of atoms into separate clouds, they were able to measure electromagnetic fields more precisely than before. The technique takes advantage of quantum connections acting at a distance. It could enhance tools such as atomic clocks and gravity sensors.

Solar geoengineering could halve the economic cost of climate change, but stopping it would cause temperatures to rebound sharply, leading to greater damage than unabated global warming

Columnist Helen Thomson investigates the neurological benefits of saunas, and how heat therapy can have anti-inflammatory effects throughout the body