Martian Mysteries: Unearthing Asteroid Remnants

This is Spacetime Series twenty eight, episode one hundred and eight, for broadcast on the eighth of September twenty twenty five. Coming up on Spacetime the discovery of asteroid remnants trapped in the Martian interior, finding the Mother's Day meteorite, and astronomers trace super fast electrons back to the Sun. All that and more coming up on Spacetime. Welcome to Space Time with Stuart Gary. A new study has concluded that asteroids which impacted Mars early in its history now lies scattered in giant lumps in the red planet's mantle. The findings, reported in the journal Science, are offering astronomer's new clues about the Martian interior and its ancient past to say what Appeeddy fragments from the aftermath of massive impacts on Mars some four and a half billion years ago have been detected deep below the red planet's surface. The discovery was made thanks to data from that is now retired Mars Insite Lander, which recorded the findings before the mission came to an end in twenty twenty two. These ancient impacts released enough energy to melt continent sized chunks of the early Martian crust and mantle into vast magnaosians, simultaneously injecting both impact of fragments and Martian debris deep into the planet's interior. There's no way of knowing exactly what struck Mars. Astronomers do know that the early Solar System was filled with a range of different rocky objects it could have impacted the red planet, including some so large they were effectively protoplanets. After all, it was a Mars sized protoplanet which slammed into the early proto Earth, eventually giving us the Moon. On Mars, the remains of these impacts still exist in the form of lumps up to four kilometers wide, which is scattered throughout the Martian mantle. They offer a preserved record only on worlds like Mars, whose lack of tectonic plates has kept their interior from being churned up the way Earth's mantle has through convection. The stadi's lead author, wrich Tatos Calambos from Imperial College London, says scientists have never seen the inside of a planet in such fine detail and clarity before It's showing a mantle studded with ancient fragments. Their survival to this day till scientists that the Martian mantle has evolved sluggishly over the last four and a half billion years. On Earth, features like these have been a raised through plate tectonics. Maas Is Mars inside Lander placed its first seismometer on the red planet's surface twenty eighteen. The extremely sensitive instrument recorded some oney three hundred and nineteen mass quakes before the lander's mission came to an end in twenty twenty two as Martian dust storms blanketed the spacecraft's solar panels, preventing it from recharging its batteries. Quakes, be they Earth, Mars or anywhere for that matter, produce seismic waves that change as they pass through different kinds of material, and that provides scientists with a way to study the interiors of planetary bodies. The Insight team we're able to use these readings to measure the size, depth, and composition not just of the Martian crust and matal, but even the planet's core. The latest discovery regarding the metals composition suggests just how much is still waiting to be discovered within inst stata. Scientists knew that Mars was the sort of time capsule bearing records of its early formation, but they didn't anticipate just how clearly they'd be able to see that through the insite data. It's all because Mars lacks the tectonic plates that produce the tremblers many people is seismically active areas are familiar with, but there are two different types of quakes on Earth that also occur on Mars, those caused by rocks cracking under heat and pressure, and those cause by meteoroid impacts. Meteoroid impacts on mass produce high frequency seismic waves, waves that travel from the crust deep into the planet's mantle, located beneath the planet's hard crust. The Martian mantle can be as much as one thousand, five hundred and fifty kilometers thick, and it's made up of solid rock that can reach temperatures as high as fifteen hundred degrees celsius. The new research identified eight mass quakes whose seismic waves contained strong, high frequency energy that reached deep into the mantle, where their seismic waves were distinctly altered. When scientists first saw this in the quake data, they thought the slow downs were happening because of the Martian crust. But then they noticed that the further seismic waves traveled through the mantle, the more these high frequency signals were being delayed. Using planet wide computer simulations, the authors saw that the slowing down and scrambling happened only when the signals were passing through small, localized regions within the mantle. They also determined that these regions p to b lumps of material with a different composition to that in the surrounding mantle. With one riddle solved, the authors then focused on another, exactly how the lumps could have gotten there. Turning back the clock, they concluded the lumps likely arrived as giant asteroids or other rocky material that struck Mars during the early Solar system's formation, generating oceans of magma as they drove deep into the mantle and bringing with them fragments of the Marsian crust and mantle. The authors liken the patterns to shattered glass, a few large chards with many smaller fragments, and the pattern is consistent with a large release of energy that scattered many fragments of material throughout the mantle. It also fits in well with current thinking that in the early Solar System, asteroids and other planets. Your bodies regularly bombarded young planets. It's all part of the accretion theory of how planets are formed. On Earth, the crust and uppermost part of the mantle is continuously being recycled by plate tectonics, pushing a plate's edge into the hot interior, where through convection, hotter or less dense material rises and cooler, denser material sinks. Mass by contrast, lacks plate tectonics, so its interior would circulate farm sluggishly. The authors say, the very fact that such fine structures are still visible today shows that Mars hasn't undergone the vigorous churning that would have smoothed out these lumps, and in that way, Mars could be pointing to what may be lurking beneath the surface of other rocky planets that lack plate tectonics, planets like Venus and Mercury. This space time still to come. Discovering the Mother's Day meteorite and astronomers trace super fast electrons back to the Sun. All that and more still to come on space time, scientists have recovered samples of a dazzling meteor which lit up the western Australian skies on Mother's Day. Researchers from Curtain University use the Desert Fireball Network, together with weather modeling, to pinpoint where the space rock would have landed and determined what direction it may have originated from. They track them it here to the Western Australian wheat built and to the remote salt flats of Lake Hope, some five hundred and thirty kilomets east of Perth. So scientists organized an expedition to search for remnants of the meteor. The journey included hundreds of kilomet is behind the wheel, hours of off road four wheel driving and a night spent camping under stars. A final seven kilometer trek by foot across Lake Hope finally brought the researchers to the impact site. That's where Desit Fiball Network team member Maya Walker made the big discovery, the impact clearly visible on the stark white flats of the Salt Lake. Meteorites such as this are valuable for scientists because it allows them to match the rock type to its origins in the Solar System by calculating the impacting orbit. They are only about sixty meteorites globally that scientists have orbital information on and this is just a tenth in Australia to be tracked and recovered by the Desert Fireball Network. The team are now analyzing the samples to determine their composition. Preliminary indications from the measurements made by Monash University indicate the rock is an L L ordinary chondrite and that's similar to the children the Blinks medior that's the one which air burst over the Southern Urals in Russia back in February twenty thirteen, generating a shockwave that caused more than fifty million dollars in damage and also let the rest of the world know just how many Russians use dash cams. The Desert Fireball Network is supported by the Curtain University Node of the International Center for Radio Astronomy Research. It uses an array of cameras spread across the country search for meteors entering its atmosphere and then allows scientists to triangulate where they landed and where to search for meteorites. Nick tim Is from Curtain University says the Mother's Day meteorite was a spectacular discovery. So as part of the Desert Fireball network, which has cameras stationed out across the Southern Australian region in the desert. They captured a fireball which streaked across the sky in the Wheat Belt of West Australia on Mother's Day and the team identified a search region where we think the fireball ended up eventually dropping a meteorite or a bunch of meteorites, and so the team went out to explore to see if they can find these meteorites via first via airplane, and had looked because of the region had lots of salt lakes and it's easy to spot something that's splashed into a salt lake recently because it makes a mark that you can see from the air. Otherwise it's searching via the bush. And so the team went out and because they'd published the search area, there was an amateur collector who was also out on the same day who was walking towards a big splash in the salt lake and he saw him basically collect a meteorite from the salt lake, and he saw them flying around looking for marks on the salt lake too. So it was a really good kind of public collaboration and out each to find this fireball. Sorry find the meteorite that was dropped by the fireball, and since then we've been analyzing that in the lab and pieces of it have been sent for basically X ray tomography, so we can see what's inside the meteorite before even putting it up, and then fragments have been sent to different labs to test around the world, so we can figure out exactly how long it's set spent in space and how much exposure it had to cosmic rays, to figure out what kind of meteorite it is and what its history is, how we can fingerprint exactly the type based on geochemistry and isotopes, and also see how it's been affected over the time by things like impacts or alteration as well. So the team actually collected many, many fragments of this meteorite that were dropped on the salt lakes and work is in progress. So watch this space and I'm sure we'll be able to tell you what some of the results are in the near future. Landing on the salt lake, it's incredibly voracious in terms of the chemical environment, it's very reactive. Meteorites react to water specifically quite readily. So the idea is to collect the rocks before they can be altered by the earth, hydrosphere or atmosphere or sitting on the ground too long, and they were able to collect the samples in this particular case within It must have been on the timeframe of a week, right from calculating from the fireball where it dropped to getting people out on the ground searching, so it was really short timeframe, so we were able to collect things really quickly. Unfortunately, the salt hadn't really reacted and water hadn't reacted with a meteorite much at all, so we got it while it's fresh, and so can we don't have to interpret through any alteration that's gone on in the meteorite while it's been on the ground. That expedition coincided with a meteorite conference being heard at KUT and tell us about it. Yeah. Absolutely. Just a month or so after the meteorite landed, we were already in line to host one of the largest conferences in the world, an international conference for meteorite experts, and we were able to show some really early results to the academics around the world in terms of meteorites, and everyone was very excited to see how we can go from sea fireball streaking across the sky to getting some really good results from the laboratory really quickly. So they were very intrigued to see some of the new results that we haven't released of the public yet, but all will be revealed in time. Let's Associate Professor Nick Tims from Curtain University, and this is space time still to come. Astronomers trace super fast electrons back to the Sun, and later in the science report, meteorologists say there's now a fifty five percent chance of the Earth being subjected to another La Nina climate event sometime between now and November. All that and more still to come on space time, Astronomers have uncovered two separate origins for energetic particles being flung into space from the Sun. The new findings, reported in the journal Astronomy in Astrophysics, helps solve a longstanding mystery. The results are based on observations by the European Space Agency's Solar Orbit Emission. The Sun is the most energetic particle accelerator in the Solar System, and it's constantly flinging high energy particles including protons, electrons, helium, nuclei, and magnetic field at nearly the speed of light out into the Solar system. This solar wind, as it's called, constantly streams out of the Sun and it bombards the Earth. Occasionally, powerful eruptions on the Sun increase the flux of these flows, flooding space with so called solar energetic electrons, and researchers have now used the solar orbit of spacecraft to pinpoint the source of these energetic electrons and trace them back to what's actually happening on the Sun itself. They found there are actually two kinds of solar energetic electrons. They each have very distinct origins. One group are connected with intense solar flare activity. Solar flares, or energetic explosions on the Sun's surface was by the twisting and snapping of magnetic field lines which extend from deep below the Sun's surface out into space through sunspots. The other group are generated by larger eruptions of solar plasma known as chronal mass ejections, which themselves are triggered by solar flares. The stadi's lead author, Alexander Walmouth from the Labnitz Institute of Astrophysics in Potchdam, Germany, is the data shows a clear split between impulsive particle events, where these energetic electrons speed off the Sun's surface in bursts through solar flares, and more gradual ones associated with more extended chronal mass ejections, which release a broader swell of particles over a much longer period of time. While astronomers had a pretty good inkling that two types of solar energetic particle events exist, Solar Orbiter was able to measure a large number of events and look far closer to the Sun than other missions in order to reveal how they form and leave the surface of our local star. Warmuth says astronomers were only able to identify and understand these two groups by observing hundreds of events at different distances from the Sun with notible measurements, something only Solar Orbiter can do. By going so close to the Sun, astronomers could measure the particles in a pristine early state and thus accurately determined the time and place they started their journey from. The authors detected the solar energetic electron events at different distances from the Sun. This let them study how the electrons behave as they travel through the Solar system, answering a lingering question about these energetic particles. See when they spot a solar flare chronal mass ejection, there's often an apparent lag between what's scene taking place at the Sun and the release of energetic electrons in space. In extreme cases, the particle seem to take hours to escape, which raises the interesting question why. Well, it turns out that this is at least partly related to how the electrons are traveling through space. See as they're flung out, they encounter turbulence, they get scattered in different directions and so are not detected immediately. These effects build up as you move further and further from the Sun. So you need to remember the space between the Sun and the planets and the Solar system isn't empty. The solar wind of charged particles streams up from the Sun consistently dragging the Sun's magnetic field with it, and it influences how the energetic electrons are traveling. Instead of morving in straight lines, they're confined, they're scattered, and they're disturbed by the solar wind and its magnetism. The study displays an important goal of solar orbiter that is to continuously monitor the Sun and its surroundings to trace ejected particles back to their source. These findings are important for sciences understanding of space weather, where accurate forecasting is essential to keep spacecraft safe. Of the two kinds of solar energetic electrons, once associated with chronal mass ejections, are more important for space weather forecasting because they tend to hold more high energy particles and so threaten far more damage. So being able to distinguish between the two types of energetic electrons is highly relevant for space where the forecasting and that helps with keeping satellites operational, maintaining communications and navigation systems, keeping astronauts safe in space from high doses of radiation, and helping to prepare for blackouts which could be caused by geomagnetic storms. This is space time, and time now to take a brief look at some of the other stories making use in science this week. With a science report, the word Meteorological Organization says there's a fifty five percent chance of a lear Nina climate at the event developing sometime between now and November. Much of the Pacific Ocean oscillates between Li Ninia and El Ninia, climatic patterns bringing cool wetter or alternatively hot or dry conditions to much of Australia. Since March, conditions have remained fairly neutral, and the World Meteorological Organization says this a forty five percent chance they'll remain that way for at least the next three months. It also means there's very little chance of an El Ninia developing. Of course, Linina and El Nino are just two of the many climatic patterns that influence temperatures. However, it's likely temperatures will remain above average for much of the world even if another Linina does develop. A new STUDI is warning that global methane emissions are continuing to increase steadily, with no signs of slowing down. The findings reported in the General Nature Communications indicate Asia and the developing Pacific region have now emerged as the largest contributors to global methane emissions. That's important because methanees actually contribute about thirty percent to global warming since pre industrial times. To reach their conclusions, the authors looked at emissions across one hundred and sixty four countries and one hundred and twenty sectors between nineteen ninety and twenty twenty three. It's important to remember that methane has global warming potential eighty times greater than that of carbon dioxide, but the authors point out that methane also has a fairly short atmospheric lifespan that means reductions today can have an immediate impact. Between nineteen ninety eight and twenty twenty three, global average methane emission coefficients dropped by nearly sixty seven percent, reflecting significant technological progress. A new study has found a link between scrolling while sitting on the toilet and an increased risk of developing hemorrhoids. The findings are reported in the General plus one surveyed one hundred and twenty five adults spending. Those who take their phone into the DUNI spend significantly more time there and also just happened to be forty six percent more likely have hemorrhoids, and that habit may be more more widespread than you realize. Some two thirds of the survey admitted to being loose scrollers. There are fresh warnings today after it was discovered that Amazon are selling a range of pseudo scientific books promoting bleach as a treatment for autism. Despite the clear danages of such a practice, Amazon have once again put profits ahead of public safety only taking one of the books off the shelves to mendum from the strand skeptics says petition's now been launched to try and pressure Amazon to act more responsibly. There is no cure for autism. Is a mental condition and its prevalent in various levels of strength through most of the population. To suggest it is one, it is a condition that needs treating, that needs curing, upsets a lot of the autistic people. And to say that bleach and we're talking about sort of industrial bleaches hit used as an enema or an oil solution to treat and perhaps purge autism out of the body, despite the fact that it's dangerous, is also a serious issue. It's a product being sold as miracle mineral solution, which is after that star. It was actually being sold by a few sort of fringe religious groups at one state. It probably still is. It's been condemned by health authorities because it can cause severe vomiting, severe diarrhea, life threatening low blood pressure from the hydration, and acute liver failure. It is not something you put inside your body, and it's certainly not something you put inside your body to cure something that can't cure it. But Amazon is selling a lot of books on this stuff release. It's got a lot of books in its catalog and over about thirty of them a claiming to cure autism in one way or another. So there's a campaign to get these books removed after Amazon, and I think they've had one of them removed so far. But the Amazon is seeing it as sort as a don't sell anything. It doesn't matter how awful it is. Jeff Bezos needs to pay for his wedding, doesn't he. That's right, Yeah, we need the money fail yet to pay for for the Venice venue. Big deal. But I mean he's making money out of this. I don't know how well these books sell. From early days of COVID when it was also being promoted to cure or treat COVID and the health people said no, don't and obleaque industry said no don't. Right, it can cull you. That's timendum from Austria and skeptics and that's the show for now. Spacetime is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher, Google podcast pocker Casts, Spotify, Acast, Amazon Music Bytes, dot Com, SoundCloud, YouTube, your favorite podcast download provider and from space Time with Stuart Gary dot com. 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