S27E16: Our Shrinking Moon

This is Spacetime Series twenty seven, episode sixteen, or broadcast on the fifth of February twenty twenty four. Coming up on Space Time, the Earth's Moon is shrinking and that means moonquakes for astronauts. NASA's analysis confirms World Meteorological Organization figures showing that twenty twenty three was the war misteir on record, and a new study indicates that stars travel more slowly around the edge of the Milky Way. All that and more coming up on space Time Welcome to Space Time with Stuart Gary. A new study has confirmed earlier research showing that the Earth's Moon is shrinking and that it's causing landslides, instability, and moonquakes around the lunar South Pole. Scientists say the findings will have consequences for the astronauts destined to explore and ultimately colonize this part of the lunar's surface. The study, reported in the Planetary Science Journal As shown that the Moon shrank more than forty six meters in circumference as it's called gradually cooled over the last few hundred million years, in much the same way as a grape will wrinkle as it shrinks down to become a raisin. The Moon also develops creases as it shrinks, but unlike the flexible skin on a grape, the moon surface is brittle, causing falseter form where sections of crust pushed past one another. Importantly, scientists of Nardis covered evidence that this shrinking of the Moon's surface has led to notable surface warping near the lunar South Pole. That's the region where NASA plans on landing its manned Artemis three mission in two years time. In fact, because of the South Pole's easy access to water, although in a frozen state deep on the floors of permanently shaded craters, the South Pole will become the likely main colonization point for future lunar missions to the lunar surface. The problem is fault formation caused by the moon shrinkage is often accompanied by searsmic activity like moonquakes, and locations within or in these such fault zones could post dangers for future human exploration efforts. The authors have already linked one group of forts located near the moon south Pole region to one of the most powerful moonquakes ever recorded by the Apollo seismometers more than fifty years ago. Using models to simulate the stability of surface slopes within that region. Site has found that some areas were especially vulnerable to landslides from seismic shaking. The studies lead author Thomas Waters from the National Air and Space Museum set for Earthen Planetary Studies, says the modeling suggests that shallow moonquakes capable of bridge using strong ground checking in the South Pole region are possible from slip events on existing faults or the formation of new thrust faults. He warns that the lunar global distribution of young thrust faults, their potential to be active, and the potential to form new thrust faults from ongoing global contraction should be considered when planning the location and stability of permanent outposts on the Moon. The study suggest that shallow moonquakes occur near the surface of the Moon, just one hundred of circular meters deep into the crust. Similar to earthquakes, shallow moonquakes are caused by faults in the lunar interior, and they can be strong enough to damage buildings, equipment, and other human made structures. But importantly, unlike earthquakes, which tend to only last a few seconds or minutes, shallow moonquakes can last for hours, even a whole afternoon. It means if we're not careful, shallow moonquakes could devastate any future human settlements on the Moon. These new findings will help prepare humans for it awaits them when they do move to the Moon, and that needs to include engineering structures so they can better withstand Luna seismic activity, thereby protecting people in the danger zones this space time still to come. A new NASA analysis confirms the World Meteorological Organization's figures that show twenty twenty three was the warmest Yuron record, and a new study shows that stars tend to travel more slowly along the outer edge of the Milky Way Galaxy. All that and more still to come on space time. A new NASA analysis has confirmed data by the World Meteorological Organization that planetarth average surface temperature in twenty twenty three was the stone record. Their data shows global temperatures last year were around one point two degrees celsius above the average for NASA's baseline period, which is between nineteen fifty one and nineteen eighty. NASA Administrator Bill Nilson says the studies by both NASA and NOAH. The National Oceanographic and Atmospheric Administration clearly confirms that planet Earth is facing a climate crisis. In twenty twenty three, hundreds of millions of people around the world experienced extreme heat, and each month from June through to December last year set a new global record for that respective month, and July ended up being the hottest month ever recorded. Overall, planet Earth was about one point four degrees celsius warmer in twenty twenty three than it was during the late nineteenth century average that's when modern record keeping began. Meanwhile, the director of NASA's god At Institute for Space Studies, Gavin Schmidt, says the exceptional warming isn't something that we've seen before in human history. He says it is being driven primarily by fossil fuel emissions, and we're seeing the impacts of this in heat waves, intense rainfall, and coastal flooding. Those scientists have conclusive evidence that the planet's long term warming trend is driven by human activity. They're still examining other phenomena that could be affecting yearly or multi yearly changes in climate, such as el Nina aerosols and pollution, and volcanic eruptions. Now typically, the largest source of yety of variability on Earth is the Al Nino Southern Oscillation Index. It's a climate pattern based around the Pacific Ocean. The pattern has two phases, El Nino and Lininia. During these phases, see surface temperatures in the Pacific along the equator tend to switch between warmer average and cool at temperatures. Now, what's been unusual of late is that between twenty twenty and twenty twenty two, the Pacific Ocean saw three consecutive Linina events, which tend to cool global temperatures. Then, in May twenty twenty three, the ocean transition from La Nina to El Nino, which often coincides with the hottest Jees on record. However, the record temperatures in the second half of twenty twenty three occurred before the peg of the current El Nino event, and scientists say they now expect to see the biggest impacts of El Nina over the next three months. But it's not just El Nino. Scientists have also been investigating the possible impacts of the January twenty twenty two eruption of the Hunger tonguahunga Ape under sea volcano, which blasted water, vapor, and fine particles and aerosols high into the stratosphere. A recent study found that the volcanic aerosols, by reflecting sunlight away from the Earth's surface, actually led to an overall slight cooling of the planet by about zero point one degree celsius that was mainly restricted to the southern hemisphere. Immediately following the eruption, Nasaus symbols at surface temperature records using air temperature data colling did from tens of thousands of meteorological stations. There's also sea surface temperature data acquired either by ship or booy based instruments. All this data is then analyzed using methods that account for varied spacing of temperature stations around the globe and for things like the urban heat effect, they could be skewing calculations. Independent analyzes by NOAH and by the Hadley Center, which is part of the United Kingdom's Met Office, have also concluded that global surface temperatures for twenty twenty three were the highest since modern record keeping began. Now, while these scientists are all using the same temperature data in their analysis. They're using different methodologies, yet they're arriving at the same conclusions. Although rankings can be slightly different between the records, they're still all in broad agreement and they clearly show that some ongoing, long term warming is taking place and has been doing so over recent decades. This report from NASTV twenty twenty three was the hottest year on record by a large margin. But why does NASA, a space agency, even look at Earth's temperature record. Let's start from the beginning. NASA's Goddard Institute for Space Studies or GIS, creates the global temperature record using land and ocean surface data collected from thousands of instruments and boobies around the world. But this critical data set of Earth's temperature has an origin story that starts one hundred million miles away on planet Venus. It's nine hundred degrees hot of the surface, has powerful high altitude winds, and is blanketed by a dense carbon dioxide. The GARDIS Suit for Space Study here in New York was set up in the early nineteen sixties to provide a connection between NASA and the academic community, and so it was very much an ideas shop, and so we spent a lot of time with the formation of galaxies and black holes and panetary program and Voyager, and we were involved very early on in some of the missions to Venus and Jupiter. Back then, when GIFs researchers were studying the weather on Venus, scientists noticed something fascinating. A thick atmosphere made up of clouds and carbon dioxide was trapping heat, so much heat that Venus had a surface hot enough to melt lead. This trapping of heat is known as the greenhouse gas effect. One of the lead Venus researchers, I guess doctor James Hansen, realized that greenhouse gases were also building up an Earth's atmosphere, so he switched his sights to his home planet and pledged to model the changing atmosphere of Earth and to verify our ground truth. As model, he needed real world measurements over time, so he began keeping track of Earth's global temperature record dating back to eighteen eighty When there was a sufficient amount of data to pull from, we used our expertise in understanding literally the clouds of Venus and the clouds and dynamics of Jupiter, and then we took that and we started to think about how you would do the same thing for the Earth. Since then, Guests has kept at sights on the global temperature record, and that was the birth of Gifts as a climate modeling institution, and scientists have seen a clear trend in that record rising temperatures, and they know why. The key difference between say, this decade and the decade before and the decade before that, is that the temperatures have been rising because of our activities, because of principally the burning of fossil fuels. Without the presence of humans, Earth's temperature would rise and fall due to a complex array of natural drivers. With human presence, however, the temperature just continues to rise. We know that by observing temperature anomalies. Measuring temperature anomalies means that we look at the change over time rather than absolute temperatures. The data map isn't showing that the Arctic style warmer temperatures than the tropics. It's saying the Arctic was that much warmer than the Arctic has been in previous years, which is an anomaly in Arctic temperatures. But how do we get those anomaly measurements Let's say you want to track if apples these days are generally larger, smaller, or the same size as they were twenty years ago. In other words, you want to track the change over time. Imagine each person on your apple measuring team has their own food scale. Person A measures apple one and their food scale rates six ounces. Person B measures the same apple, but their scale reads seven ounces. Since these scales are calibrated differently, your team ended up with two different recorded weights for the same exact apple. There's some imprecision in the measurements, and to account for that when you compare this apple's measurement to the apples growing next year, you'll need to look at their difference rather than absolute weights, focusing on the anomaly, or how much heavier or lighter than next apple is from year to year. So for temperatures, while it would be great to have the same exact scale or thermometer all over the world measuring the temperature in the same exact way, we don't. Instead we focus on how much warmer or colder the temperatures are in each place, based on their own instruments. Another factor to consider is, since you're tracking apples from all over the globe, there are differences in baseline weights. Let's say apples grown in Florida are generally larger than apples grown in Alaska. Like in real life, how Floridian temperatures are generally much higher than Alaskan temperatures. So how do you track the change in apple size is from apples grown all over the world while still accounting for their different baseline weights by focusing on the difference within each area rather than the absolute weights. So when it comes to the temperature record, scientists aren't comparing temperatures in Bermuda to temperatures in Greenland and averaging them together for net warming. Instead, they're comparing the change in temperatures in Bermuda to the change in temperatures in Greenland. Again, we look at the anomaly measurements to track the change over time. Now let's scale this example up. If you have a weather station that's say here in New York City, and you compare it to a weather station in Washington, d C. Or Montreal, they tell very different stories about the absolute temperature. Right, So Montreal is colder and the Washington d C Is often warmer. But when they move up and down, when there's a month that is warmer or colder, it's basically the same in all three locations. And so by looking at the anomalies how much warmer it is than normal for that particular point, and then you look at those anomalies at all those different points and you can average those. It turns out that you can fill out the gaps much more effectively. This big picture global temperature is comprised of much smaller concentrated data points from all over the world. So while globally temperatures average out to be record hot, it wasn't record hot in every single location around the world. But why did twenty twenty three see record heat? Well, to put it simply, a combination of high greenhouse gas emissions and the transition out of three consecutive years of Lannina conditions and into al Nino conditions led to record breaking heat, But the year was in some respects still surprisingly hot, and NASA is continuing its research on why. Typically the largest cause of short term year to year differences in temperature is usually La Nina and al Nina weather patterns. Laninia generally cools things down while warms them up. The largest cause of long term decade by decade differences in temperature is greenhouse gas emissions and the subsequent trapped heat by greenhouse gases. So while we don't expect every year to be a new record like twenty twenty three, we do expect new records as long as we continue to increase greenhouse gas emissions. The key thing to take away from all of this is that the long term trends are pretty much relentlessly up. We're going to continue to have records be broken because that baseline is moving all the time, and then the weather is sitting on top of that, and so when the weather is warmer than normal, then we're going to get these records. But even when it's cooled in the normal, we don't go back to what it was. And in that report from That's a TV, we heard from Gavin Schmidt, the director of NASA's got Out Institute for Space Studies, this space Time Still to Come a you study show stars travel more slowly around the edge of the Milky Way galaxy, and later in the science report, your research shows that people who sit for long periods of time at work have a sixty percent higher risk of death. All that are more still to come on space time By clocking the speed of stars throughout the Milky Way Galaxy, physicists have discovered that stars further out on the galactic disc are traveling more slowly than expected compaired to stars that are closer to the galaxy center. The findings, reported in the Monthly Notices of the Royal Astronomical Society's Journal, erasing the possible ability that the Milky Wate gravitational core may be lighter in mass and contain less dark matter than previously thought. The new results are based on an analysis of data taken by both the GYA and APERGE instruments. GIA is an orbiting space telescope run by the European Space Agency. It's tracking the precise location, distance and motion of more than a billion stars throughout the Milky Way Galaxy. Meanwhile, APERGY is a ground based survey telescope. The physicist analyzed GUIAS measurements of more than thirty three thousand stars, including some of the furthest stars in the galaxy, and they determined eight stars circular velocity. Now, circular velocity is how fast the star is circling the galactic disc given the stars distance from the galactic center. The authors then plotted each star's velocity against its distance to generate a rotational curve. It's a standard graphic astronomy representing how fast matters rotating at at given distance from the center of a galaxy. The shape of this curve and gives scientists an idea of how much visible and dark matter is distributed throughout the galaxy. One of the studies authors, Lena A. KiB from the Massachusetts Institute of Technology MIT, says what really surprised the authors was that this curve remained flat, and it continued to stay flat all the way out to a certain distance, and then it suddenly started tanking away. This means the outer stars of the galaxy are rotating a little slower than expected, which is a very surprising result. The authors then translated this new rotational curve to a distribution of dark matter that could explain the outer stars slow down. They found the resulting map ended up producing a lighter galactic core than what was expected. In other words, the center of the Milky Way galaxy might be less dense with less dark matter than what astronomers had always thought. The new results, therefore, are in clear tension with other measurements. The authors say there's something fishy going on somewhere. Like most galaxies in the universe, our milky Way spins, I guess sort of like water at a whirlpool, and its rotation is driven in part by all the matter that's swirling within the disk. It was back in the nineteen seventies when astronomer Verra Ruben became the first to observe that galaxies rotate in a way that cannot be purely driven by their visible matter. Ruben and colleagues measured the circular velocity of stars and found that the resulting rotational curves were surprisingly flat. That is, the velocity of the stars going around the center remained the same throughout the galaxy, whether or not they were close to the center or out near the edge. Their rotational curves weren't dropping off with distance. Rubon and colleagues concluded that some other type of invisible matter, stuff we now call dark matter, must be acting on distant stars to give them an additional push. In this regard, Ruben's work in rotation curves was one of the first strong pieces of evidence for them in the existence of dark matter, an invisible, unknown entity which we know exists and must make up more than three quarters of all the matter in the universe. Since then, astronomers have observed similar flat curves in other far off galaxies, further supporting dark matters presence. But only recently of astronomers attempted to chart the rotation curve in our own galaxy with stars, and it turns out it's a lot harder to measure the rotational curve when you're actually sitting deep inside the galaxy. Back in twenty nineteen, Anachristina Elliots from MIT worked to chart the Milky Way's rotation curve using an earlier batch of data release by Geyer. Now that data release included stars as farret as twenty five Killer Parssex, which is about eighty one thousand light years from the galaxy center. Now, based on these data, Elliots observed that the Milky Way's rotation curve appeared to be flat, although with a mild decline, similar to other far off galaxies, and by inference, our galaxy likely bore a high day density of dark matter at its core. But this view is now shifted as guys released a new batch of data, this time including stars as far at as thirty kilo Parssex. That's almost one hundred thousand light years from the galaxy's core. Now these distances, astronomers are looking right at the edge of our galaxy, the place where stars are starting to peter out. No one's ever explored how much matter moves around in this outer galaxy region. It's where we're really starting to touch the nothingness of intergalactic space. So as you can imagine, the studies authors jumped on Guys' latest data at least late last year, looking to expand on at least initial rotation curve. To refine their analysis. They complemented the gay A telescope data with measurements by APERGEY, the Apergey Point Observatory Galactic Evolution Experiment. It's measuring extremely detailed properties of more than seven hundred thousand stars in the Milky Way, such as their brightness, their temperature, and their elemental composition. The data is then fit into an algorithm try and learn connections that can give scientists a better estimate of a star's distance. The authors use this data to establish a precise distance system more than thirty three thousand stars, and use these measurements to generate a three dimensional map of the stars scattered across the Milky Way out to around thirty kilo Parssex. They then incorporated this vast map into a model of circular velocity in order to simulate how fast any one star must be traveling given the distribution of all the other stars in the galaxy. They then plotted each star's velocity and distance on a chart in order to produce an updated rotation curve of the whole Milky Way itself, and that is where the weirdnesses come in. Instead of seeing a mild decline like previous rotation curves, the authors observed that this new curve get far more strongly than expected at the utter end. Now, this unexpected downturn suggest that while stars may be traveling just as fast out to a certain distance, they then suddenly slow down beyond this distance. When the team transition this rotation curve to the amount of dark matter that must exist throughout the galaxy, they found that the Milky Waiste core must contain far less dark matter than what they had previously estimated. The result is clearly intension, with other measurements. Really understanding the meaning of this result will undoubtedly have debrief percussions. This could simply be leading to more hidden masses just beyond the edge of the galactic disk, or could mean a total reconsideration of the state of the equilibrium of our galaxy. You can be sure of one thing, whatever unfolds will be fascinating. This is space time. Time out to take a brief look at some of the other stories making use in science this week with a science report. A new study has shown that people who sit for prolonged periods of time at work wind up having a sixteen percent higher risk of death from any cause and a thirty four percent higher risk of heart disease. The findings were reported in the Journal of the American Medical Association, based on research which followed almost five hundred thousand people over thirteen years. The study looked at how much the participants sat at work, how much they exercised in their free time, as well as their health outcomes and any deaths over the thirteen year period. The researchers say those who sat all day at work but exercise for fifteen to thirty minutes a day outside work had a similar risk of death to people who weren't sitting at work remained inactive during their free time. The researchers say their study supports the evidence that their jobs can be harmful to health. Reducing the amount of time you sit at work and exercising more outside working hours can help reduce the risks. A new Australian led study claims average global temperatures they already have risen by one point five degrees celsius above pre industrial levels. Aiming to limit temperature rises to one point five degrees celsius or below was the goal of the Paris Climate Agreement struck in twenty fifteen. While previous estimates of warnings based on sea surface temperature records, these only date back to the mid nineteen hundreds, these new findings, reported in the journal Nature Climate Change, are very different. They're based on data from species of long lived sea sponges. These primitive animals contain hundreds of years of data and chemical changes within their skeletons, and this can be used by scientists to estimate temperatures from March earlier. So the researchers used samples of these sponges from species from the Eastern Caribbean in order to explore temperatures over the last three hundred years, and they say their estimates show that one point five degrees celsius of warming relative to pre industrial levels has already been reached. A new study warns that outdoor artificial lighting at night could be linked to an increased risk of macular degeneration, a leading cause of irreversible blindness. A report in the Journal of the American Medical Association looked at some four thousand and seventy eight patients newly diagnosed with age related macular degeneration, as well as one hundred and twenty two three hundred and forty people without the disease, all over the age of fifty. After estimating people's exposure to artificial outdoor light at night using satellite data from around their addresses, the authors found higher levels of outdoor artificial lighting at night was linked to a higher risk of developing age related macular degeneration. While this kind of research can't confirm whether lighting at night courses blindness, the researcher say the findings do add to a body of research showing how much artificial light at night could be impacting your health. It's been revealed that the sleepy eastern English county of Bedfordshire, often described as the country's most boring place is actually a hotbed of pagan satanic activity. The title is England's most boring county is based on the twenty eighteen Yugov poll of forty two thousand people. But what's not so well known is that the same area is regarded as the nexus of sorts. There are deconsecrated churches, strange ancient rock monuments, modible claims of demonic visitations, and a long history of witch trials and Wickerman festivals. Even today, it's claimed many villages in the area still have regular black masses and at least two or three practicing witches. Thousand year old May festivals still take place in the region, and one village even has a bizarre pancake day witch listening. Tales of the devil stealing children and the souls of the wicket abound. Timendum from Australian skeptics who actually lived in this county for some time, since the area was part of the Viking ruled Dane Law and as a longer pagan history than Anglo Saxon Wessex, with Celts practicing the Druid religion once common throughout the county. In fact, lived in Bedfordshire for about a year, yes, so, which proves what a hot beta is actually of everything. Bedford Shire is in the middle of England, sort of lower middle. The biggest town is Luton, famous for the Luton Girls Choir, which doesn't exist anymore. It's not the most exciting, I'm told, the most boring county in England. Yeah, aparently there was a survey people, so I don't know how many people in Bedfordshire decided that. But there's a lot of hidden secrets in Bedfordshire. It is an old county and there's a lot of old buildings in it. I think that was one of the ones I lived in. Was pretty old and certainly elite. But what they have tanners? One person described as sort of that. Bedfordshire is known for two things, hack making and Satanism. Right, interesting combinations you'd normally put together, are they? Well? I don't know what Satans wear on their head. Maybe they have particular hats that you only get in bed Also the horns, wouldn't you that's right. I'm sure every county in England, Scotland, Whale wherever, and a lot of other places as well have their fair share of ghosts and haunted houses and halted castles and churches, run down churches, and strange occurrences. So what they stand out. There's a whole range of sort of strange people who have lived there in the past, well more than other places, I don't know. There's characters who are involved in witchcraft and witch hunters and witches and people who supposedly had evil powers over other people, and strange occurrences, people coughing up needles and pins and all sorts of stuff. It was actually home, I don't know if it's in Bedfordshire or in neighboring county, which was the hell Fire Club, which was the famous other sort of gentle members of the late seventeen hundreds early eighteen hundreds who used to do all sorts of stranger They used to do it for the hell of it, and they were notorious for being the baut they're seen to be. There's a lot of watch pitlets of time anyway in that ere pit, with more money than there and plenty of time to do stuff. One of the interesting things is that they actually refer to that one of the small towns that I lived in there was a town called Layton Buzz. It's the one little name for Tanning and the people think it actually comes from Latin voters are and that was quite sure. But Layton Bosa sounds good, which has a church called Old Saints Church which is in the middle of the market town actually and it's got ancient graffiti of a basilisk cover and a demon cart into the stoneworks. Now there was another church in the in vetrity which actually has the devil's footprints in the front step. Trouble is they renovated the church and they were really fact I thought there was strange That would have been a great tourist thing. But anyway, Bedfordshire, regarded by the survey as the most boring county in England, does have its fair share of strange occurrences and things, and I think that should be celebrated. That's Timendum from Austria in Skeptics and that's the show for now. The Space Time is available every Monday, Wednesday and Friday through Apple podcast, iTunes, Stitcher, Google podcast, pocker Casts, Spotify, Acast, Amazon Music, bites dot Com, SoundCloud, YouTube, your favorite podcast download provider, and from space Time with Stuart Gary dot com. Space Time's also broadcast through the National Science Foundation on Science Own Radio and on both iHeartRadio and tune In Radio. 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