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Meteorites strike Earth every day. It’s estimated that about 100 – 300 metric tonnes of material strike our planet every year. Most of it consists of sand-grain sized dust that burns up in the atmosphere, but each year a few thousand will reach Earth’s surface.

The vast majority of meteorites trace their origins to comets or the asteroid belt, but some of them come from the Moon or Mars. We know this by analyzing their chemical composition. While the Lunar meteorites have much to tell us, it is the Martian meteorites that are the greatest treasure for they are the only fragments of the Red Planet we currently have. By studying their chemistry and composition we have learned that Mars was once a warm and wet world similar to Earth.

There are about 200 meteorites we have confirmed as Martian in origin. There composition shows that they likely originated from about 10 large impacts on Mars. To be powerful enough to throw fragments of Mars into space, the impacts must have been large enough to make sizable craters, perhaps dozens of kilometers across. Which raises an interesting question. Which particular craters are connected to the meteorites we have? A new study in Science Advances explores this question.

A fragment of a Martian meteorite. Credit: Brian Koberlein

The team started by looking at the chemical similarities in each group of associated meteorites. From this they could get an idea of the age and geology of a particular impact site. They then compared this to the known age and composition of various regions of Mars, looking for craters that were a reasonable match. They were able to find an originating crater for about five of the groups.

This is important because knowing the precise origin gives us a more accurate picture of the evolution of Mars. We already have a good general understanding of the early history of Mars, but with specific impact sites we can compare regions. Perhaps early seas existed on Mars while other regions became deserts. Which regions were the last to dry, and therefore might be good sites for finding evidence of life. The study also found impact craters that are similar to the ones that produces meteorites but have no associated meteorites. As we find more Martian rocks, they might be part of new groups originating from these impacts.

Until we can recover rocks from Mars directly, the couple hundred Martian meteorites are our only physical link to our red neighbor. And thanks to this study we have a better idea of that link.

Reference: Herd, Christopher DK, et al. “The source craters of the martian meteorites: Implications for the igneous evolution of Mars.” Science Advances 10.33 (2024): eadn2378.

The post Most Mars Meteorites Came From Five Craters appeared first on Universe Today.

How certain are you of anything that you believe? Do you even think about your confidence level, and do you have a process for determining what your confidence level should be or do you just follow your gut feelings?

Thinking about confidence is a form of metacognition – thinking about thinking. It is something, in my opinion, that we should all do more of, and it is a cornerstone of scientific skepticism (and all good science and philosophy). As I like to say, our brains are powerful tools, and they are our most important and all-purpose tool for understanding the universe. So it’s extremely useful to understand how that tool works, including all its strengths, weaknesses, and flaws.

A recent study focuses in on one tiny slice of metacognition, but an important one – how we form confidence in our assessment of a situation or a question. More specifically, it highlights The illusion of information adequacy. This is yet another form of cognitive bias. The experiment divided subjects into three groups – one group was given one half of the information about a specific situation (the information that favored one side), while a second group was given the other half. The control group was given all the information. They were then asked to evaluate the situation and how confident they were in their conclusions. They were also asked if they thought other people would come to the same conclusion.

You can probably see this coming – the subjects in the test groups receiving only half the information felt that they had all the necessary information to make a judgement and were highly confident in their assessment. They also felt that other people would come to the same conclusion as they did. And of course, the two test groups came to the conclusion favored by the information they were given.

The researchers conclude (reasonably) that the main  problem here is that the test groups assumed that the information they had was adequate to judge the situation – the illusion of information adequacy. This, in turn, stems from the well documented phenomenon that people generally don’t notice what is not there, or at least it is a lot more difficult to notice the absence of something. Assuming they have all relevant information, it then seems obvious what the answer is – whichever position is favored by the information they are given. In fact, the test groups were more confident in their answers than the control group. The control group had to balance conflicting information, while the test groups were unburdened by any ambiguity.

There are some obvious parallels to the real world here. There is a lot of discussion about how polarized the US has become in recent years. Both sides appear highly confident that they are right, that the other side has lost their collective mind, and nothing short of total political victory and any cost will suffice. This is obviously a toxic situation for any democracy. Experts debate over the exact causes of this polarization, but there is one very common theme – the two sides are largely siloed in different “information ecosystems”. This is the echochamber effect. If you listen mainly or only to partisan news, then you are getting one half of the story, the half that supports your side. You will have the illusion that you have all the information, and in light of that information the conclusion is obvious, and anyone who disagrees must have dark motives, or be mentally defective in some way.

I have seen this effect in many skeptical contexts as well. After watching or reading a work that presents only half the story – the case for one side of a controversy – many people are convinced. They think they now understand the situation, and feel that such a large amount of information has to add up to something. I have had many discussions, for example, with people who have rad books like The Aquatic Ape, that argues that humans went through an evolutionary period of adaptation to an aquatic life. It’s all nonsense and wild speculation, without any actual science, but it’s hard not to be persuaded by a book-length argument if you don’t already have the background to put it into context. The same happened with many people who watched the movie Loose Change.

This is why it is a good rule of thumb to suspend judgement when you encounter such claims and arguments. Professionals in investigative professions learn to do this as part of their deliberate analytical process. What am I not being told? What information is missing? What do those who disagree with this position have to say? What’s the other side of the story?

This is a good intellectual habit to have, and is also a cornerstone of good skepticism. Who disagrees with this claim and why? In everyday life it is a good idea to have diverse sources of information, and in fact to seek out information from the “other side”. For political news, no one source can be adequate, although some sources are better than others. Not all news sources are equally partisan and biased. It’s a good idea to seek out news sources that are generally considered to be, and may have been rated, to be less partisan and are balanced in their reporting. But it is also a good idea to utilize multiple sources of news, and to specifically consume news that is of reasonable quality but comes from a different position than your own. What is the other side saying and why? It may be painful and uncomfortable sometimes, but that is a good reason to do it.

It’s good to know that there is a bias towards the illusion of information adequacy, because with that knowledge you can work against it. In the study, when the test subjects were given the other half of the information that they were initially missing, many of them did change their minds. This is something else we often see in psychological studies – humans are generally rational by default, and will listen to information. But this is true only as long as there is no large emotional stake. If their identity, tribe, ego, or fundamental world view is at stake, then rationality gives way to motivated reasoning.

This is why it is extremely useful (although also extremely difficult) to have no emotional stake in any claim. The only stake a rational person should have is in the truth. Your identity should be as an objective truth-seeker,  not as a partisan of any kind. Also there should be no loss in ego from being wrong, only from failing to change your mind in light of new evidence. This is a rational ideal, and no one achieves it perfectly, but it’s good to have a goal.

At least it’s good to be engaged in metacognition, and to think about your thought process and everything that might be biasing it. This includes information and perspective that might be missing. This is the most difficult to detect, so it requires special attention.

The post Confidently Wrong first appeared on NeuroLogica Blog.

Accumulated evidence does not demonstrate that elderberry has meaningful beneficial effects.

The post Elderberry (What is it good for) first appeared on Science-Based Medicine.

We often talk about Jupiter’s Great Red Spot quite candidly but forget that hurricanes can be devastating, destructive forces here on Earth. Hurricane Milton is a reminder of the awful effects here on Earth. It came out of nowhere, appearing in the Gulf of Mexico as a tropical storm and two days later was a category 5 hurricane. It tracked a course and hit land near Siesta Key in Florida. NASA have been tracking the storm from space, recording high sea temperatures that fuelled the storm allowing it to grow. Images have been released from the ISS showing the sheer enormity of the hurricane.

Hurricanes form over warm oceans, typically in tropical regions of Earth. Their formation tends to start as a collection of thunderstorms over bodies of water where the temperature is at least 26.5 degrees celsius. The warm, moist air over the ocean rises creating a region of lower pressure at the surface.

Hurricanes Gordon and Helene

The low pressure causes air to flow inward, warming and rising as it goes. It then cools and condenses to form clouds that release the heat. The heat then warms the surrounding air creating a continuous cycle of rising warm air and an inward movement of air. The system grows and eventually takes on a rotational movement due to the rotation of the Earth. When the winds are recorded to be sustained above 119 kilometres per hour, it is classed as a hurricane. They can continue to grow as long as their is a source of warm moist air so typically they hit landfall and start to weaken. 

Watch this video of Hurricane Milton from the International Space Station

The inhabitants of Florida only just recovered from the effects of Hurricane Helene before warnings were received from another hurricane brewing over the Gulf of Mexico. Hurricane Milton started to form on 5 October and two days later had become a category 5 hurricane. Fuelling this leviathan of a hurricane are the higher than average sea temperatures in the Gulf of Mexico. Milton’s wind speeds rapidly increased from 28 to 281 kilometres per hour in 24 hours as the hurricane strengthened. 

It wasn’t just warm oceans that intensified Milton so rapidly though, vertical wind shear was also a vital component. This change in winds with height interacts with the brewing thunderstorms to usually diminish a hurricanes ferocity. In the case of Milton, it was in a low-shear environment which means with changing altitude, there is usually very little difference in wind speed or direction. This allowed the storm to grown without being checked. 

Thunderstorms over Brazil

The National Hurricane Centre (part of the National Oceanic and Atmospheric Administration) have been tracking Milton since its formation, paying particular attention to where it was likely to hit land and what path it was likely to follow. They were also able to determine (largely from imagery and data from orbiting infrastructure) that an eye-wall replacement cycle had completed. This process occurs when a new eye begins to develop around the old eye. The new eye slowly decreases in size and eventually replaces the old eye. Events such as these can cause the hurricane to grow but reduce wind speed. It can happen several times but then grow in intensity again if the conditions permit.

The eye of Hurricane Milton can be clearly seen in this image from the International Space Station 

International Space Station. Credit: NASA

With astronauts on board the space station and the remote sensing technology available to them, NASA are a key part of disaster management teams. Their Disasters Response Coordination System has been used to support agencies dealing with the storm on the ground. They provide maps, images and data to help manage flooding, power outages and rain fall levels. 

Our thoughts go out to all those effected by Hurricane Milton from all the team at Universe Today. 

Source : Fuel for Hurricane Milton

The post NASA Reveals the Mind-Boggling Scale of Hurricane Milton seen from Space appeared first on Universe Today.

Ancient volcanic rock from South Africa has been found to harbour primitive bacteria, which may shed light on some of the earliest forms of life on Earth

The total number of exoplanets discovered to date totals 5,288. Among them are a host of rocky, Earth-like exoplanets but none of them seem to have atmospheres. It’s a fairly challenging observation to make but a team of researchers think they’ve come up with a new, simpler technique. It involves measuring the combined temperature of a star and the exoplanet just before the planet passes behind. If it’s lower than expected, the planet is likely to have an atmosphere regulating its temperature!

The search for alien worlds has of course in itself an exciting journey. Finding other planets around distant stars helps us to understand more about possibility of life in the Universe. Finding other planets that could sustain life is perhaps one of the most exciting goals in modern science. Before we can get to that stage however, we need to first find worlds with atmospheres. 

Coronagraph allowing the direct imaging of exoplanets

Atmospheres around Earth-like planets are key components for the development of life (I should add life like us since there could be a whole host of different biologies out there!) The layer of gas surrounding rocky worlds insulates the planet and acts to regulate its temperature to. Our own atmosphere warms during the day and cools at night but it redistributes the heat of the Sun around the planet keeping it a moderately temperate climate for life. 

A view of Earth’s atmosphere from space. Credit: NASA

A new study led by PhD student Qiao Xue from the University of Chicago has developed an intriguing new way to hunt for Earth-like planets with an atmosphere. Typically we we have relied upon the study of the light from the host star as the planet passes in front to reveal the presence of an atmosphere. It’s an approach which turns out to be far more efficient and simpler than previous methods. 

The idea was first proposed in 2019 by Bean and Megan Mansfield to analyse the temperatures of the exoplanet and the star. More accurately the difference between the temperature of the exoplanet when at its hottest and the predicted temperature at its coldest. An atmosphere around an exoplanet would disperse the heat around the surface, reducing the day time temperature. The team theorised that if the actual temperature of an exoplanet is not as hot as it could be then an atmosphere must be present and redistributing the warmth. Until now thought, the technology was not sensitive enough. The James Webb Space telescope has changed that though.

Artist impression of the James Webb Space Telescope

As an exoplanet passes in front of the host star, some of the star’s light is blocked and so the overall brightness decreases. As the planet passes almost behind the star then the light from the star and a little from the exoplanet allows for a measure of the brightness of the full system. As the planet passes behind then we can measure stellar brightness alone and, analysing the changes in light, the brightness and hence temperature of the planet can be deduced. 

Using this technique, the team applied their attention to planet known as GJ1132 b 41 light years away. They concluded that it does not have an atmosphere because its measured temperature is too close to the calculated maximum temperature. It therefore cannot have an atmosphere redistributing the energy from its host star. It is therefore not a suitable candidate for live!

Source :  UChicago researchers use new method of finding atmospheres in distant planets

The post A New Way to Detect Rocky Exoplanet Atmospheres appeared first on Universe Today.

Two of the three science Nobel prizes in 2024 have been won by people working in AI, but does this mean that AI models are now vital for science?

Mars has captured our imagination for centuries. Ever since the invention of the telescope our imagination has often drifted toward the possibility of life on Mars. Exploration of the red planet has often revealed that Mars once had plenty of water on its surface but it’s no longer there. Now NASA’s Curiosity rover has found deposits of carbon-rich minerals that could give us a much needed clue.  

Mars Curiosity Rover was launched by NASA to the red planet in 2011. It’s part of the Mars Science Laboratory mission and, like many of the explorers, is a robotic mission. It arrived at Gale Crater on 6 August 2012 and was designed to explore the geological and climatic environments of Mars, search for signs that it was once a habitable world and to that end, was essentially a sampling and analysis mission. Originally it was a two year mission but Curiosity has continued long passed the intended duration, operating now for over a decade.

New simulations are helping inform the Curiosity rover’s ongoing sampling campaign. Credit:NASA/JPL-Caltech/MSSS

Mars, the fourth planet from the Sun, has been known to be a fairly hostile world devoid of any signs of life. Gale Crater was chosen as the target for Curiosity because it’s an impact crater formed just under 4 billion years ago. The layered rock formations found on the crater walls make it an ideal location to study the red planets geological history. The analysis is completed using the on board instruments SAM (Sample Analysis at Mars) and TLS (Tunable Laser Spectrometer) that heat up the samples to almost 900 degrees Celsius with the resultant gasses being analysed.

There’s methane on Mars, but only in Gale Crater, and only sporadically. Image Credit:

As Curiosity explores Mars it has been measuring the isotopic composition (the ratios of different isotopes) of the minerals found in the crater. Isotopes are elements that have different masses than usual for example as water evaporates, lighter version of carbon  and oxygen were likely to evaporate leaving heavier ones behind. Eventually, over time, the heavier versions (isotopes) became an integral part of the rocks that Curiosity is analysing. The minerals are largely carbon rich but they point toward high levels of evaporation suggesting they could only have formed when Mars could support liquid water. 

David Burtt from NASA’s Goddard Space Flight Centre and lead author of the paper that describes the findings do not rule out ancient life either. He said “Our samples are not consistent with an ancient environment with life on the surface of Mars, although this does not rule out the possibility of an underground biosphere or a surface biosphere that began and ended before the carbonates formed.”

Their paper that was published in the National Academy of Sciences suggests there may have been two possible formation processes for the carbonates. A series of wet-dry cycles within the Gale Crater are one such possibility with the formation of carbonates in highly salty water under cold temperatures the other. 

The two possible formation scenarios point to two different climate models and different habitability.  The wet-dry cycling suggests an alternating climate between more and less habitable conditions. Alternatively the salty water process with cold temperatures would indicate a less habitable environment with most water locked up in ice and the rocks. Neither scenario is ideal for the establishment of complex life forms but as Burtt highlighted, it doesn’t rule out the possibility further back in the history of Mars. 

Source : NASA: New Insights Into How Mars Became Uninhabitable

The post How Did Mars Become Uninhabitable? appeared first on Universe Today.

Researchers have significantly improved a new joining technology, interlocking metasurfaces (ILMs), designed to increase the strength and stability of a structure in comparison to traditional techniques like bolts and adhesives, using shape memory alloys (SMAs). ILMs offer the potential to transform mechanical joint design in manufacturing for aerospace, robotics and biomedical devices.

A team of international researchers has developed a natural fabric that urban residents could wear to counter rising temperatures in cities worldwide, caused by buildings, asphalt, and concrete.

Research observing the physical motion of falling ice crystals could help scientists better estimate where and when these crystals will melt into raindrops.

Researchers took the imaginary scenes from Spider-Man seriously and created the first web-slinging technology in which a fluid material can shoot from a needle, immediately solidify as a string, and adhere to and lift objects.

A professor who has devoted his career to resolving the mysteries of higher mathematics has solved two separate, fundamental problems that have perplexed mathematicians for decades.

Artificial Intelligence has learned to master language, generate art, and even beat grandmasters at chess. But can it crack the code of abstract reasoning --t hose tricky visual puzzles that leave humans scratching their heads? Researchers are putting AI's cognitive abilities to the test, pushing the multi-modal large language models (MLLMs) to solve visual problems once reserved for human IQ tests. The result? A glimpse into how far AI has come -- and where it still stumbles.

Astronomers have observed Jupiter's legendary Great Red Spot (GRS), an anticyclone large enough to swallow Earth, for at least 150 years. But there are always new surprises -- especially when NASA's Hubble Space Telescope takes a close-up look at it. Hubble's new observations of the famous red storm, collected 90 days between December 2023 to March 2024, reveal that the GRS is not as stable as it might look. The recent data show the GRS jiggling like a bowl of gelatin. The combined Hubble images allowed astronomers to assemble a time-lapse movie of the squiggly behavior of the GRS.

Hurricanes often produce tornadoes that add to the destructive power of the storm – and climate change may make such tornadoes more common

Scientists are using mechanisms inspired by nature to create new technological innovations. A team has now created an octopus-inspired adhesive, inspired by the shape of octopus suckers, that can quickly grab and controllably release challenging underwater objects. Having the ability to grab and release these underwater objects like heavy rocks, small shells, and soft beads, and other debris could be a powerful tool for underwater salvage and even rescue operations.

Chirality -- a geometric property that allows molecules to exist in two distinct forms that are chemically identical but are 3D mirror images of each other, like a right and left hand -- has a powerful effect on nuclear spin state but was thought to have no effect on coupling between spins. A study found chirality, or handedness, does in fact determine the strength of a coupling between nuclear spins. Findings could lead to better methods of probing electrons and spin in chemical and biological systems.

For decades, scientists knew there was a huge swath of undetected and unaccounted for per- and polyfluoroalkyl substances (PFAS) in the atmosphere, often referred to as PFAS dark matter, but no one knew how much was missing or how to measure them. Now, an atmospheric chemistry research team has devised a way to test for one of the most ubiquitous elements of these potent greenhouse gases.

A research team has devised a unique method to observe changes in materials at the atomic level. The technique opens new avenues for understanding and developing advanced materials for quantum computing and electronics.