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Microbial communities feeding on geothermal methane seeps beneath the Antarctic ice sheet could resemble life-supporting environments on frozen worlds in our solar system and beyond

A network of Earth's best clocks will be synchronised with the most accurate one ever sent into space. But the device has a short shelf life: it will burn up in the atmosphere at the end of the decade as the ISS deorbits

Water filters made from untreated wood can remove more than 99 per cent of particles, taking out many harmful bacteria and microplastics

What can Helium-3 (3He) being discharged from the Sun teach us about 3He creation and the Sun’s activity? This is what a recent study published in The Astrophysical Journal hopes to address as an international team of researchers investigated 3He-rich solar energetic particles (SEPs) emitted by the Sun in late 2023. This study has the potential to help astronomers better understand how solar activity could contribute to the production of 3He, the latter of which remains one of the most desired substances due to its potential for nuclear fusion technology on Earth.

Two new studies have sparked fresh debate about a faraway planet with a weird atmosphere. One of the studies claims additional evidence for the presence of life on the planet K2-18 b, based on chemical clues. The other study argues that such clues can be produced on a lifeless world.

Sometimes an old telescope can still impress. That is certainly the case for Hubble, which is rapidly approaching the 35th anniversary of its launch. To celebrate, the telescope's operators are collaborating with ESA to release a series of stunning new photographs of some of the most iconic astronomical objects the telescope has observed. As of the time of writing, the latest one to be released is a spectacular new image of a favorite of millions of amateur astronomers - the Sombrero Galaxy.

A study has found a rare form of one-dimensional quantum magnetism in a metallic compound, offering evidence into a phase space that has remained, until now, largely theoretical. The study comes at a time of growing global interest in quantum materials that redefine the boundaries between magnetism, conductivity, and quantum coherence.

Scientists have created the first neutron 'Airy beam,' which has unusual capabilities that ordinary neutron beams do not. The achievement could enhance neutron-based techniques for investigating the properties of materials that are difficult to explore by other means. For example, the beams can probe characteristics of molecules such as chirality, which is important in biotechnology, chemical manufacturing, quantum computing and other fields.

Who knew that magnetic fields could be so useful?

Everything in the Universe spins. Galaxies, planets, stars, and black holes all rotate, even if just a bit. It comes from the fact that the clouds of scattered gas and dust of the cosmos are never perfectly symmetrical. But the Universe as a whole does not rotate. Some objects spin one way, some another, but add them all up, and the total rotation is zero. At least that's what we've thought. But a new study suggests that the Universe does rotate, and this rotation solves the big mystery of cosmology known as the Hubble tension.

The report of possible biosignatures on the exoplanet K2-18b is exciting, but we are a long way from establishing beyond doubt that there is life on such a distant world

When Roman Egypt came under attack from the Kushites in what is now Sudan, the Roman forces responded by destroying a Kushite city – or so we thought

New global rules will see a carbon levy applied to emissions from shipping for the first time, but analysts say the package falls short of what is needed

Two independent research teams have developed methods for hacking noisy quantum computers based on a row-hammer attack, a type of interference used to infiltrate traditional computers

Colossal Biosciences’s "de-extinction" news is just the latest in a slew of eyebrow-raising claims by privately funded researchers. Is the bar for belief lower when those making the claims have a lot of money, wonders Jonathan R. Goodman

As the US government freezes scientific funding and attacks my host institution (under the pretense of fighting anti-semitism — a claim no one here believes, given that the government is now doing far more actual harm to Harvard’s not-so-small population of Jewish faculty, researchers and students than was ever done by anti-Gaza-war protestors), it has become impossible to continue with my normal activities. I hope to resume them in the future.

Exoplanets are pretty exciting – in the last few decades we have gone from knowing absolutely nothing about planets beyond our solar system to having a catalogue of over 5,000 confirmed exoplanets. That’s still a small sample considering there are likely between 100 billion and 1 trillion planets in the Milky Way. It is also not a random sample, but is biased by our detection methods, which favor larger planets closer to their parent stars. Still, some patterns are starting to emerge. One frustrating pattern is the lack of any worlds that are close duplicates of Earth – an Earth mass exoplanet in the habitable zone of a yellow star (I’d even take an orange star).

Life, however, does not require an Earth-like planet. Anything in the habitable zone, defined as potentially having a temperature allowing for liquid water on its surface, will do. The habitable zone also depends on variables such as the atmosphere of the planet. Mars could be warm if it had a thicker atmosphere, and Venus could be habitable if it had less of one. Cataloguing exoplanets gives us the ability to address a burning scientific question – how common is life in the universe? We have yet to add any data points of clear examples of life beyond Earth. So far we have one example of life in the universe, which means we can’t calculate how common it is (except maybe setting some statistical upper limits).

Finding that a planet is habitable and therefore could potentially support life is not enough. We need evidence that there is actually life there. For this the hunt for exoplanets includes looking for potential biosignatures – signs of life. We may have just found the first biosignatures on an exoplanet. This is not 100%. We need more data. But it is pretty intriguing.

The planet is K2-18b, a sub-Neptune orbiting a red dwarf 120 light years from Earth. In terms of exoplanet size, we have terrestrial planets like Earth and the rocky inner planets of our solar system. Then there are super-Earths, larger than Earth up to about 2 earth masses, still likely rocky worlds. Sub Neptunes are larger still, but still smaller than Neptune. They likely have rocky surfaces and thick atmospheres. K2-18b has a radius 2.6 times that of Earth, with a mass 8.6 times that of Earth. The surface gravity is estimated at 12.43 m/s^2 (compared to 9.8 on Earth). We could theoretically land a rocket and take off again from its surface.

K2-18 is a red dwarf, which means it has a habitable zone close in. K2-18b orbits every 33 days, and had an eccentric orbit but staying within the habitable zone. This means it is likely tidally locked, but may be in a resonance orbit (like Mercury), meaning that it rotates three times for every two orbits, or something like that. Fortunately for astronomers, K2-18b orbits in front of its star from our perspective on Earth. This is how it was detected, but also this means we can potentially examine the chemical makeup of its atmosphere with spectroscopy. When the planet passes in front of its star we can look at the absorption lines of the light passing through it to detect the signatures of different chemicals. Using this technique with the Hubble astronomers have found methane and carbon dioxide in the atmosphere. They have also found dimethyl sulfide and a similar molecule called dimethyl disulfide. On Earth the only known source of dimethyl sulfide is living organisms, specifically algae. This molecule is also highly reactive and therefore short-lived, which means if it is present in the atmosphere it is being constantly renewed. Follow up observations with the Webb confirmed the presence of dimethyl sulfide, in concentrations 20 times higher than on Earth.

What does this mean? Well, it could mean that K2-18b has a surface ocean that is brimming with life. This fits with one model of sub-Neptunes, called the Hycean model, which means they can have large surface oceans and an atmosphere with lots of hydrogen. These are conditions suitable for life. But this is not the only possibility.

One of the problems with chemical biosignatures is that they frustratingly all have abiotic sources. Oxygen can occur through the splitting of water or CO2 by ultraviolet light, and by reactions with quartz. Methane also has geological sources. What about dimethyl sulfide? Well, it has been found in cometary matter with a likely abiotic source. So there may be some geological process on K2-18b pumping out dimethyl sulfide. Or there may be an ocean brimming with marine life creating the stuff. We need to do more investigation of K2-18b to understand more about its likely surface conditions, atmosphere, and prospects for life.

This, unfortunately, is how these things are likely to go – we find a potential biosignature that also has abiotic explanations and then we need years of follow up investigation. Most of the time the biosignatures don’t pan out (like on Venus and Mars so far). It’s a setup for disappointment. But eventually we may go all the way through this process and make a solid case for life on an exoplanet. Then finally we will have our second data point, and have a much better idea of how common life is likely to be in our universe.

The post Possible Biosignature on K2-18b first appeared on NeuroLogica Blog.

The 2000-year-old Antikythera mechanism may have been a kind of astronomical calculator, but researchers are unsure whether it would have worked without jamming

When science was under attack, Dr. John Ioannidis played the role of enabler. Along with his copious COVID misinformation, that will be his permanent legacy.

The post Tell us Dr. John Ioannidis, Exactly Who is Waging This “War on Science”? first appeared on Science-Based Medicine.

The idea of varying your lifestyle throughout your menstrual cycle to help relieve PMS or period pain seems intuitive, but the evidence reveals a nuanced picture, finds columnist Alexandra Thompson