MAVEN's Silence: Unravelling the Mystery of Mars' Lost Contact

This is Spacetime Series twenty eight, Episode one hundred and forty seven, for broadcast on the fifteenth of December twenty twenty five. Coming up on Spacetime, NASA loses contact with its MAVEN Mars orbiter, how the cosmic landscape impacts the galaxy's life cycle, and a new study suggests the planet's urinus and net tune might be rock giants rather than ice giants. All that and more coming up on Spacetime. Welcome to space Time with Stuart Gary. NASA has lost contact with its Mars Atmosphere and Volatile Evolution or MAVEN spacecraft. The agency says the probe disappeared off the proverbial screens on December sixth, at the time Pelimetary showed MAVON was working nominally as it passed behind Mars is seen from Earth, but the spacecraft didn't resume communications after emerging from behind the planet. Mission managers are now investigating the anomaly and are yet to determine what's gone wrong. The orbit has been circling the red planet for more than a decade, gathering scientific data and serving as a key communications relay satellite. MAVEN launched back in November twenty thirteen and entered orbit around Mars in September twenty fourteen. The spacecraft's primary mission has been to study the planet's upper atmosphere and interactions with the soil or wind, including how the atmosphere escapes into space, helping scientists better understand how the Red Planet changed from a warm, wet world with a thick atmosphere, one capable of supporting liquid water on its surface and turning it into the inhospitable freeze driede desert it is today this report from NASA TV. Today, morris Is are called dry world, with a tenuous atmosphere only one percent as thick as Earth's. But in the ancient past, water flowed freely across the Martian surface, maintained by a thick early atmosphere. Since it first arrived at the Red Planet in September twenty fourteen, NASA's Maven spacecraft has been studying how that atmosphere was lost to space and with it the water. In twenty fifteen, Maven observed the solar wind eroding the Martian atmosphere. The solar wind is a stream of electrically charged particles blowing from the sun. Mavon watched as ions from the Mars upper atmosphere were accelerated by the solar winds magnetic field and driven into space, confirming that this process has deeply eroded the Martian atmosphere. In twenty seventeen, Maven showed that a process called sputtering has had an even greater effect on the atmosphere. When ions from Mars get picked up by the solar winds magnetic field, they can crash into neutral atoms at the top of the atmosphere, sputtering them into space. Mayvin measured present day isotopes of argon, which can be removed only by sputtering, to determine that sixty five percent of the noble gas has been lost over time. This allowed scientists to estimate the escape of other gases and determine that sputtering has been the primary mechanism driving the atmosphere into space. Later in twenty seventeen, Maven revealed a twist in Mars's invisible magnetic tail. When the Sun's magnetic fields reach Mars, they pile up and wrap around the planet, creating an induced magnetic field that is drawn out behind Mars like a comet's tail. The marching crust also contained small pockets of its own early magnetic field, which rotate along with the planet. Mayvin discovered that when these two fields interact, they put a twist in the magnetotail, confirming model predictions. In twenty eighteen, a runaway series of dust storms created a dust cloud so large that it developed the planet. During this global dust storm, MAVEN observed an abrupt, unexpected spike in the amount of water in the upper atmosphere. It discovered that heating from dust storms can loft water molecules far higher into the atmosphere than usual, leading to a sudden surge in water loss to space. Later in twenty eighteen, MAVEN announced the discovery of a new type of aurora at Mars. The mission had previously observed auroras during solar storms after electrons from the Sun struck the upper atmosphere, causing it to glow with ultraviolet light. Mavin's twenty eighteen discovery was the first observation of a Mars proton aurora. When protons from the solar wind pick up electrons from the Martian ionosphere, they can slip through the planet's bowshock and plunge into its upper atmosphere. Causing widespread auroras. On Earth, proton auroras are isolated near the poles, but on Mars they can bathe the day side in ultraviolet radiation. In twenty nineteen, MAVEN produced the first map of wind currents in the Martian thermosphere, revealing disturbances and high altitude winds caused by terrain features on the surface. MAVEN scents these disturbances as it skimmed through the upper atmosphere, feeling the imprint of mountains and valleys far below. In twenty twenty, data for MAVIN led to the creation of another new map showing the Martian atmosphere's electric current systems for the first time. MAVIN detected these currents indirectly by observing the solar winds magnetic field lines drape around the planet. Mapping the electric current systems can help scientists to better understand the forces that dry atmospheric escape. In twenty twenty two, MAVIN watched as the solar wind unexpectedly disappeared from Mars. The event occurred when a fast moving patch of the solar wind overtook a slower moving region, leaving a void in its wake. In response, the Martian magnetosphere ballooned outward by thousands of kilometers, engulfing Maven's orbit and causing the solar wind to temporarily disappear from view. In twenty twenty two and twenty twenty three, Maven captured stunning ultraviolet images of Mars when the planet was near opposite ends of its elliptical orbit. The first image was taken when the southern hemisphere was in summer, which coincides with Mars's closest approach to the Sun. Canyons and basins are covered with a thin haze of ozone, indicated by a tinge of pink. The second image was taken during northern spring, after Mars had passed its furthest point from the Sun. White clouds hint at rapidly changing conditions in the northern polar regions, while deep magenta signals a build up of ozone during the frigid winter. In twenty twenty four, Maven observe the aftermath of an X class solar flare, the strongest type of eruption from the Sun. The flare was quickly followed by a burst of charged particles crashing into Mars, leaving black and white streaks on images. Taken by NASA's Curio City rover. Mayvin watched from above as auroras lit up the planet in a brilliant display of celestial fireworks. Mavin's other role as a communications relay satellite has provided a key link between both the Mars Curiosity Mass Perseverance rovers down on the Martian surface and mission managers at the Jetpropulsion Laboratory in Passa into California by way of NASA's Deep Space Communications Network ground stations Broadstone, California, Madrid, Spain, and Camera, Australia. NASA's Mars Odyssey spacecraft and Mass Reconnaissance Orbiter also service communications relays for the rovers, but both are significantly older than Maven, and this isn't the first time that MAVEN has suffered technical issues. Back in twenty twenty two, the probe's inertial measurement units, which are used for navigation, failed That forced mission managers to switch the orbital to still a navigation system, minimizing reliance on the inertial measurement unit. Maybe has enough propellant to maintain its orbit through at least until the end of the decade. This is space time still to come. How a cosmic landscape can impact the galaxies life cycle, and a new study suggests the solar systems to ice giants urin a s in Neptune might actually be more rocky than icy. All that and more still to come on space time, a new study is shown how a galaxy's neighborhood can influence its evolution. The findings, reported in the Monthly Notices of the Royal Astronomical Society, offers a new level of detail into science's understanding of galactic evolution in the distant universe. The research is based on data from Devils the Deep Extragalactic Visible Legacy Survey, an extensive galaxy evolution survey which shows that a galaxy's local environment plays a major role in how it changes over time, strongly influencing its shape, size, and even its growth rate. The survey combines data from a wide range of terrestrial and space based telescopes to investigate various aspects of astrophysics for analyzing hundreds of thousands of galaxies. The project lead Luke Davies from the University of Western Australia node of the International Center for Radio Astronomy Research, says the DEVIL Survey is unique in that it's the first of its kind to explore detailed aspects of the distant universe. It focuses on galaxies that existed up to five billion years ago and examines how these galaxies have changed through to the present day. He says, while previous surveys during this period of universal history have explored the broad evolution of galaxy properties, they've inherently lacked the capacity to determine the finer details of the cosmic landscape. The Devil Survey has allowed astronomers to zoom in and focus on mapping out the small scale environment of galaxies. This new approach has allowed Davies and colleagues to identify the number of stars in the galaxy, understand ongoing star formation, and analyze their visual appearance, shapes, and structures. They can then compare these properties between galaxies and the present day universe with galaxies that existed around five billion years ago in order to determine how galaxies have changed over time. They found that galaxies that are surrounded by lots of other galaxies. One might say that bustling centers of galactic cities in the cosmos tend to grow more slowly and have different structures compared to their more isolated counterparts. In crowded regions of the universe, galaxies interact with each other and compete for resources such as gas. The full new stars and grow. Devi says this competition can impact the evolution and in some instances cause star formation to slow down earlier than expected, causing galaxies to die. The survey that's primarily based around observations which are done with the Anglo Australian Telescope in New South Wales. So what we do is we pick a few patches of the night sky and we take a lot of imaging data that currently exists in those regions and we put it together to build a sample of galaxies so we want to explore. And then we go to the Angle Australian Telescope and we measure spectra for all of those galaxies. And what that primarily allows us to do is to measure the three dimensional structure of the universe. So we map out the distances and the positions of all of the galaxies and then we determine what the structure looks like, and we use that structure to work out places in the universe where there are lots of galaxies so very sort of overdense regions which you are sort of bustling city centers of the universe environment. So they're mostly galaxy groups, which are slightly smaller than clusters. So given the. Volume, yeah yeah, so sort of from the local group size up to a little bit bigger, mainly because of the volumes that we probe are quite small in comparison to the nearby universe, so you actually don't get some of the really massive to type things. Then what we do is we try and combine all the information about what the galaxy's local environment is like, so how clustered the regions are, and link that up with the properties of the galaxies to see how where they live is impacting their life cycle. And what if you found. What we found is that when you start to map out the universe of this sort of smallish scale in terms of environments, that the properties of galaxies are very strongly linked to where they live in the universe. So if you grow up in bustling sort of city centers of the galactic environment, you actually die more easily, you form less stars, you look different, you grow in a different way. If you live in a sort of isolated, remote region of space. I would have thought that if you're in a busy, bustling area with lots of other galaxies, it'd be easier to steal gas from them and make more stars and even grow bigger because you can merge with them. That's not what you found. That, So that's largely true for the sort of big central galaxies in those environments. We tend to split galaxies in those to centrals and satellites, where central is sort of the main big galaxy in the middle, and the satellites are all the other ones which are moving around it. So for the central region, being in that overdent environment actually helps it to grow more massive, but for the satellites it actually stops them from forming new stars so that they don't grow any bigger. And all of those interactions with the other galaxies actually change the way the galaxy looks as well. So we define how a galaxy looks at something called morphology, which basically defines whether it's sort of a big, blobby red structure or a disc like spiral structure. And where a galaxy lives in its environment and its interactions other galaxies changes the type of morphology that that galaxy is is that. Why the large and small metrole any clouds are disrupted spirals or irregular spirals rather than grand spirals like say the Milky Way. Or yeah, so they're also much smaller. So these sort of smaller regular galaxy tend to form as more sort of blobby structures. But yeah, their interactions with the Milky Way will make them look different. So imagine if you have like say, have two big spirally type galaxies and you smash them both together, you end up with something that looks more like an elliptical galaxy. And because those processes are happening more readily in group environments, you end up getting more elliptical like things in group environments than you would in isolated environments. The real benefit of what we've done with devils in this is that this type of science of mapping out the sort of group scale so that the much lower mass scale than clusters environments, there's only previously been done in the relatively local universe. The reason for this is that to be able to map out the three dimensional structure of a universe, you need to measure red shifts basically for lots of galaxies to get to their distance, and doing that outside of the local universe is really problematic because you have to observe for a really long time to get enough signal to noise to measure the red shifts. So we've done this in the local universe with other surveys, but with Devils, what we've done is we've stretched that out into the much more distant universe by observing the same galaxy for much longer time basically to get their red shifts. It is the first time we've really managed to map out this sort of group scale structure in the very distant universe. And you're moving from Devils to Waves next. Yeah, So Waves is a survey that's going to be starting next year on a new facility which is called Foremost, which is the four meter multi object Spectrograph telescope which is in Chile. And what we're doing with WASTE is that we actually have a few different sort of surveys that we're doing, but one of the components of WAVES, which is called Waves Deep, is basically the same as Devils, but over a much much larger area. So essentially we'll be doing all of the science that we can do with Devils now, but to a much much finer degree of a much larger volumes of the universe. We actually have got the first test observations from Foremost for some of the galaxies in waves, which has been really exciting. So we've all been working away to try and understand everything that's going on with the telescope, and then we'll start waves in earnest next year. One of the big topics of recent papers that I've seen has been this ongoing hypothesis that the Milky Way may not be within a strand of galaxies in the cosmic web of the universe, but rather it may actually be at or near the edge of a larger void. Has your work in any way it all help resolve that issue. The issue of this is is that some of our results in terms of our cosmological analysis, so analysis of how the whole universe works essentially and how the whole universe is evolving, are a little bit in tension with each other. And one of the possible solutions for that is that we live in a slightly atypical part of the universe, so next to a cosmic void, which would mean that some of our measurements that we use to insfer cosmological principles are a little bit wrong because all of those assume basically that we live in a very representative place in the universe. Now, it is really super interesting, but it's not really something that I work on massively. I look at galaxies which are much much further away than that local volume. But there is an Australian lead survey that's going to be happening on Foremost as well, called the VOHS, which is being run from the country, which will actually test some of these things about the distribution of galaxies in the very local universe as well. So I would say hold types and in sort of four or five years time, when we have results from Foremost, we might be able to say something a bit more about this proper. The reason for this assumption that we're in a of the edge of a void is simply because of studies looking at an expansion of the universe based on dark energy. Yeah, so that's one of the cosmological measurements that I mentioned. So there's currently just this tension as to how dark energy is evolving and whether it's changing with time or whether it's a constant. And one of the potential solutions to all of this conflict is that we live within this void, which actually allows you to match up some of the sort of slightly disparate observations that you get from doing different measurements. It's a small void if it is a void. Yeah. The interesting thing is, of course, there have been some new results that have just come out showing that dark energy isn't constant, but in fact we have not just reached the maximum extent of dark energy, but it may be going in reverse now. Yes, So most of those results are coming out of a civic or DESI, which is done in the northern hemisphere and not to bang on about Foremost too much, as a pretty amazing instrument when it starts going. But there's also a different survey that's going to be done not Foremost, which is a survey which is similar to DESI, but will be in the southern hemisphere. So when that's done, combining the data from DESI and this Foremost survey in the Southern hemisphere will actually produce way better constraints on all of these measurements. So it's quite exciting that we might have sort of DESI times two in about five years time where we get much better constraints on all of this, and we'll probably then get a definitive answer onto whether dark energy is changing with time or is constant. Let's associate Professor Luke Davies from the University of Western Australia NERD of the International Center for Radio Astronomy or Research, and this is space time still to come, and you study suggest the Solar Systems to ice giant planets during a s and neptune may actually be more rocky than I see. And later in the science report and you study warns insufficient sleep may sure in your lifespan. All that and more still to come on space time, A new study suggests the Solar Systems two ice giant planets urin a set tune might actually be more rocky than icy. The findings follow new computer simulations examining the likely internal structures of the two worlds. Now this new study isn't claiming that these two blue planets are one type of the other, water or rock. Rather, it simply challenges the idea that ice rich isn't the only possibility. This new interpretation is also consistent with the discovery that the dwarf planet Pluto is rock dominated in its composition. The planets in our Solar System are typically divided into three broad categories based on their general composition. There are the four terrestrial rocky planets Mercury, Venus, Earth, and Mars, then the two gas giants Jupiter and Satin, and finally the two ice giants. You're in a sl Neptune. Now. According to the new work carried out by the University of Zeris scientific team, Urinus and Neptune might actually be more rocky than icy. The studies lead author Luca morph says the ice giant classification might be an oversimplification, but he admits both words are still poorly understood and models on the two based on physics are two assumption heavy, while imperial models are too simplistic. Morphin colleagues combined both approaches in order to get internal models of the two planets that are both agnostic and physically consistent. To do this, they first started with random density profiles for each planet's interior based on a numerical framework. They then calculated planet to gravitational fields in a way that was consistent with the observed data available and that allowed them to infer a possible internal composition. Finally, the process is repeated to obtain the best possible match between models and observational data, and the authors found that the potential internal comps position of the pair isn't limited to mostly ices. Instead, a new range of internal compositions show that both planets can either be water rich ice or rock rich material. The study has also brought a new perspective on both Uranus and Neptune's puzzling magnetic fields. While the Earth has clear north and south magnetic poles, magnetic fields of Uranus and Neptune are far more complex and include more than just two poles. The new models show ionic water layers, which generate magnetic dynamos at locations that help explain the observed non dipolear magnetic fields. They also found that Urinus's magnetic field originates far deeper inside the planet than that of Neptune. While these new results are promising, uncertainty still remains. One of the main issues is that physicists still barely understand how materials behave under the exotic conditions of pressure and temperature which are found at the heart of a planet, and that will impact result aults. Still, despite the uncertainties, these new results are paving the way for new potential interior composition scenarios, scenarios which are challenging decades old assumptions and which could guide future research into planetary conditions. This is Space Time and time out to take a brief look at some of the other stories making news in science this week. With a science report, A new study warns insufficient sleep made sure in your life. The findings, reported in the journal's Sleep Advances, compared sleep patterns with life expectancy, and the authors found that as a behavioral driver for life expectancy, sleep stood out far more than diet, exercise, loneliness, and indeed more than any other factor except smoking. For the study, the CDC that Centers for Disease Control and Prevention define sufficient sleep as at least seven hours per night, which is recommended by the American Academy of Sleep Medicine and by the Sleep Research Society. Although previous research is shown broadly that a lack of adequate sleep does lead to high mortality risk, the new research is the first to reveal year to year correlations between sleep and life expectancy. The war With Meteorological Organization says there's now a fifty five percent chance of a week Linina weather pattern developing over the next three months. Lenina conditions typically bring higher rainfall and cooler temperatures across Australia, and the studies authors say climate has been at borderline Lenina conditions since mid November. The agency says Leninia is just one of the climatic patterns influencing our weather, with climate change also having a major impact on temperatures and extreme weather events. One of the longest and most intact segments of Jerusalem City Wall has been uncovered by archeologists with the Israeli Antiquities Authority. The remarkably war preserved segment dates back to the Hassamian Macabeen period of the late second century BCEE, some two hundred years before Christ and eight hundred years before the birth of Islam. The ancient Jewish fortification was unearthed within the Kishel complex at the Tower of David, adjacent to the historic Citadel. The newly uncovered segment is over forty meters long and some five meters wide. It was built from massive stone blocks that were finally dressed with a distinctive chisel bass typical of the Hassemonian period. The authors believed the wall originally stood over ten meters high. Similar sections of the defensive system had been uncovered around Mount Zion, the City of David, the courtyard of the Citadel, and along parts of the western boundary of Jerusalem, but none are as extensive or as well preserved. A new study by NOAH, a National Oceanic and Atmospheric Administration, has to bunk the idea that increases in atmosphere carbon dioxide levels will provide long term improvements in plant growth skeptics. Timendum says, well, some increases in satto levels are beneficial for plants, too much does end up killing them. A lot of people are saying that because we're putting our carbon dioxide as part of our sort of energy activities, and that plants take in carbon dioxide to help them grow, if it's a good thing we're putting out the food that plants used. That's actually, to a certain extent, a little extent, that's correct. Plants do take on carbon dioxide, and there can be times when they flourish in certain environments where the trouble is you can have too much and plants can only absorb so much in the same way as the sea can only absorb so much. In fact, it's the sea, which is absorbing most of the carbon dioxide that is absorbed, So the tree is going to take so much they can bloom and blossos and then after while it'll start to kill them. And then when it kills them, you get droughts, so it gets less trees and that sort of stuff. Also, of course, when a plant dies, it gives up the carbon dioxide it's taking in of storing siche for trees and things like that. So the argument has been put forward by a lot of people saying that carbon dioxo is good for plants and things and therefore we'll reforest. Everything is wrong, and this has been shown both in laboratory work and in atmospheric work and satellite photography. So what will happen is sudlants will flurries and then die. So when they die, you get dropt, you get low crop yield. That's timendum from Austria in Skeptics, and that's. The show for now. Space Time is available every Monday, Wednesday and Friday through bytes dot com, SoundCloud, YouTube, your favorite podcast download provider, and from space Time with Stuart Gary dot com. Space Time is also broadcast through the National Science Foundation on Science and radio and on both Heart Radio and tune in radio. And you can help to support our show by visiting the space Time Store for a range of promotional merchandising goodies, or by becoming a Spacetime Patron, which gives you access to triple episode commercial free versions of the show, as well as lots of burnus audio content which doesn't go to wear, access to our exclusive Facebook group, and other rewards. Just go to space Time with Stewart Gary dot com for full details. You've been listening to space Time with Stuart Gary. This has been another quality podcast production from bytes dot com