Solar Secrets Unveiled - Solar Orbiter's Ground-breaking detail of the Sun's South Pole

[00:00:00] This is SpaceTime Series 28 Episode 73, broadcast on the 18th of June 2025. Coming up on SpaceTime, Solar Orbiter captures unprecedented views of the Suns' turbulent South Pole. The moons of Uranus are providing surprises for scientists. And Europe's new Ariane 6 rocket prepares for its third flight. All that and more coming up on SpaceTime.

[00:00:26] Welcome to SpaceTime with Stuart Gary. Astronomers have had their first ever detailed look at the Suns' South Pole. The spectacular new observations by the joint NASA-ESA-Solar Orbiter spacecraft are showing

[00:00:56] scientists a sight of our local star never seen before. See, the thing is, virtually all spacecraft that explore the Sun are viewing our local star from the ecliptic, that's the plane upon which the planets orbit the Sun. Now, although this plane is slightly tilted relative to the Sun's equator, the angle's about 7 degrees, it's simply not enough to get a clear view of our star's poles. And solar telescopes on Earth naturally have the same limited perspective.

[00:01:23] In fact, only the Ulysses spacecraft, a joint mission by the European and American space agencies ESA and NASA, has flown over the Sun's poles. It did that several times between 1990 and 2009, although from a much greater distance than Solar Orbiter and without any imaging instruments on board. The Sun's poles are of special interest to scientists. The processes taking place there are thought to play a decisive role in the Sun's 11-year solar cycle.

[00:01:51] Roughly every 11 years, and that's about now, the Sun reaches solar maximum, the peak of its solar activity cycle. And as we're seeing right now, during this period, the Sun is especially active, with violent bursts of radiation and particles driven into space by solar flares and coronal mass ejections. The result is space weather events, geomagnetic storms. In fact, in recent weeks alone,

[00:02:16] these have triggered some very impressive auroral activity. Normally seen at higher latitudes, these aurora have become visible at lower latitudes, even as far north as Sydney just the other week. Also, the number of sunspots on the solar surface tends to increase as we approach solar maximum. Sunspots are areas of especially high magnetic field strength that appear on the Sun's visible surface. These magnetic fields tend to suppress temperatures, thereby making the area appear cooler,

[00:02:44] consequently darker, than the surrounding surface. Magnetic field lines stretch out from these areas and extend deeper to space. Different parts of the Sun rotate at different rates, and so consequently, these magnetic field lines tend to twist and ultimately snap, releasing loads of energy, before reforming again through magnetic reconnection, releasing even more energy. Now between periods of solar max, the Sun's violent activity tends to drop dramatically,

[00:03:11] often for months at a time, with few if any sunspots or eruptions. This is known as solar minimum. The last solar minimum was in November 2019, and the next is likely to be in 2030. The basis of these solar cycles, our Sun's internal clock if you will, isn't fully understood. But astronomers suspect that a key piece of this solar puzzle could lie in a deeper understanding of the

[00:03:36] solar poles. And so finding these pieces of the puzzle is one of the most important mission objectives of solar orbiter. Now getting to the Sun is difficult enough. It's intense gravity wants to pull everything in and destroy it. And so spacecraft flying to study the Sun will use a planet like Venus as a gravity assist mechanism to act as a brake, slowing it down and allowing it to change its course. So instead of crashing into

[00:04:00] the Sun, it loops around the Sun. And depending how the spacecraft orbits around Venus as part of its braking procedure, it can change its trajectory. And instead of going along the ecliptic, you can instead swing to higher latitudes. To this end, the probe used the momentum of its flyby of Venus on February the 18th this year to leave the ecliptic. And about a month later, on March the 22nd, the probe looked at the Sun from an angle of 17 degrees for the first time.

[00:04:27] The project's principal investigator, Sammy Solanke from the Max Planck Institute, said scientists didn't know exactly what to expect during these first observations. You see, the Sun's poles are quite literally terra incognita. The new images were taken on March the 16th and 17th, just a few days before the probe reached its highest deflection from the ecliptic, an angle of 15 degrees. The data was collected by Solar Orbitus Plyerometric and Helioseismic Imager, which captures visible

[00:04:55] light and images of the Sun's surface as well as its magnetic field. Other instruments that worked during these observations included the extreme ultraviolet imager and spectral imaging of the coronal environment or SPICE instrument. These looked at higher layers of the Sun up to the hot solar corona. And the images from these instruments will help scientists better understand how the Sun manages the fleeing solar wind material into space. The images are showing the magnetic field near the

[00:05:22] Sun's south pole to be in a state of turmoil. In general, the Sun's magnetic field is much more complex than that of the Earth. There are many small, variable and highly complex magnetic structures there. These often occur either in connection with sunspots or at the poles, and they all combine to generate the Sun's large-scale global magnetic field. During much of the Sun's solar cycle, the magnetic field resembles a bar magnet, with the Sun's north and south pole spin axis roughly

[00:05:51] corresponding to its magnetic north and south poles. But during solar max, the Sun's north and south magnetic poles reverse polarity. In simple terms, the south pole becomes north and the north pole flips to south. It's thought the small magnetic structures seen at the poles are likely to play an important role in this process, although scientists really don't know what that role is yet. We know that one magnetic polarity is likely to predominate during solar minimum, but the magnetic field should

[00:06:19] be slightly more complex during solar max. And now these latest observations are confirming that hypothesis. At the south pole, the observational data is revealing an intricate jumble of small areas of different polarities. Luckily, Solar Orbiter was able to map the magnetic field at the south pole at a key moment, and scientists are now following the polar magnetic field's restructuring. In fact, by the end of next year, Solar Orbiter will be able to observe the north and south poles of the Sun three more times,

[00:06:48] from an angle as much as 17 degrees. Then another gravity-assist flyby of Venice on December 24th next year will further tilt the probe's orbit, allowing it to rise to 23 degrees above the ecliptic. That will provide an even better view of the poles. And needless to say, we will keep you informed. This is space-time. Still to come, the moons of the planet Uranus surprising scientists.

[00:07:13] And Europe's new Ariane 6 rocket prepares for what will be its third launch into orbit. All that and more still to come on space-time. Scientists are surprised by new surface observations of the

[00:07:41] largest moons of Uranus. Using NASA's Hubble Space Telescope to study the four largest moons of the ice planet Earth. And the Earth's planet Earth. And the Earth's planet Earth. And the Earth's planet Earth. But while they went into the study looking for evidence of one hypothesis, the observations they came up with resulted in a new and entirely different hypothesis coming to light. See, the authors predicted that based on interactions with the planet's magnetosphere, the leading sides of

[00:08:11] these tidily locked moons, which are always facing the same direction in which they're orbiting the planet, should be brighter than the trailing sides, which are always facing away. Now that would be due to radiation darkening of their trailing sides. And that's caused by charged particles such as electrons trapped in Uranus's magnetosphere. The trouble is, the ultraviolet observations made by NASA's Hubble Space Telescope showed no evidence of darkening on the moon's trailing sides. But it did find clear evidence of darkening on the leading sides of the two outer moons.

[00:08:41] Now the surprising results suggest Uranus's magnetosphere might not interact much with its large moons, contradicting existing data collected over near-infrared wavelengths. The four moons in this study, Ariel, Amriel, Titana and Oberon, are all tidily locked to Uranus. That means they always show the same side to the planet. Just like the Earth's moon is tidily locked to the Earth, always showing us, the lunar near side. The side of the moon facing the direction of travel is called the leading

[00:09:11] hemisphere, while the side that faces backwards is called the trailing hemisphere. The thinking was that the charged particles trapped along the moon's magnetic field lines primarily would hit the moon's trailing side, which would therefore darken that hemisphere. The study's lead author, Richard Cartwright from Johns Hopkins University, points out that Uranus is weird because it's tipped over on its side. In fact, it's tilted by some 98 degrees relative to the ecliptic. So it's always been uncertain just

[00:09:37] how much the magnetic field actually interacts with its satellites. It all means Uranus is dramatically tipped relative to the orbital plane of the planets. In fact, it rolls very slowly around the Sun on its side as it completes its 84 Earth-year orbit. Back at the time of the Voyager 2 flyby in the 1980s, the magnetosphere of Venus was tilted by about 59 degrees from the orbital plane of the satellites. And so we know there's an additional tilt to the magnetic field. And because Uranus and its magnetic

[00:10:06] field lines rotate faster than its moons orbit the planet, the magnetic field lines constantly sweep past the moons. If the magnetosphere of Uranus interacts with the moons, charged particles should preferentially be hitting the surface of the trailing sides. And these charged particles, as well as galactic cosmic rays, should wind up darkening the trailing hemispheres of Ariel, Umbral, Titania and Oberon, and possibly even generate the carbon dioxide detected on these moons. Cartwright and colleagues expected that's what

[00:10:35] would be happening, especially for the inner moons Ariel and Umbral. The trailing hemispheres should be darker than the leading hemispheres in ultraviolet and visible wavelengths. The trouble is that's not what they found. Instead, both the leading and trailing hemispheres of Ariel and Umbral are actually very similar in brightness. And that's puzzling. Even more puzzling, the authors did see a difference between the hemispheres of the two outer moons, Titania and Oberon, not the moons they expected. Even stranger,

[00:11:03] the difference in brightness on these two moons was opposite from what they expected. The outer moons, it turns out, have darker and redder leading hemispheres compared to their trailing hemispheres. So what's going on? Well, the authors think that dust from some of Uranus' irregular satellites is actually coating the leading sides of Titania and Oberon. See, irregular satellites are natural bodies that have large eccentric and inclined orbits relative to the parent planet's equatorial plane.

[00:11:31] And micrometeorites are constantly hitting the surface of Uranus' irregular satellites, thereby ejecting small bits of material into orbit around the planet. And over millions of years, this dusty material moves inwards towards Uranus and eventually crosses the orbits of Titania and Oberon. These two outer moons then sweep through this dust and pick some of it up, primarily on their leading hemispheres which are facing forward. I guess you could think

[00:11:57] of it sort of like bugs hitting the windshield of your car as you drive down a road. And so this material is causing Titania and Oberon to have darker and redder leading edge hemispheres. And these outer moons are effectively shielding the inner moons, ariel and unreal, from the dust, which is why the inner moons' hemispheres aren't showing any difference in brightness. Based on all these new findings, Cartwright and colleagues suspect that Uranus' magnetosphere may be fairly quiescent. Or on the other hand, it may be more complicated than previously thought.

[00:12:26] Perhaps interactions between Uranus' moons and the magnetosphere are happening, but for some reason they're not causing asymmetry in the leading and trailing hemispheres as the authors had suspected. A mystery for our times. This is space time. Still to come, Europe's new Ariane 6 rocket prepares for what will be only its third ever launch. And later in the science report, a new study suggests that the Dead Sea Scrolls are even older than traditionally thought.

[00:12:54] All that and more still to come on Space Time. The European Space Agency have begun the countdown to the launch of their new heavy lift booster rocket,

[00:13:18] the Ariane 6. Flight VA264 is slated to launch in August on what will be only the third ever launch for ESA's new flagship rocket. The maiden flight of the Ariane 6 back in July last year successfully reached orbit and achieved both stage separation and payload deployment. But then the upper stage failed to reignite a third engine burn designed to deorbit the spacecraft when its VINCI propulsion system failed.

[00:13:43] Luckily, things went better on the second flight, Ariane Space VA263. It successfully launched in March this year carrying the French military CSO-3 reconnaissance satellite into orbit. This latest mission, Ariane Space Flight VA264, will carry a new 4,000 kilogram meteorological satellite the Metop SG, which will be placed into an 831 kilometre high orbit. The Ariane 6 is thought to be a major improvement on the previous Ariane 5 which it replaces.

[00:14:12] It's both more economical and easier to build with more parts commonality. The core stage utilizes an upgraded version of the same liquid hydrogen, liquid oxygen, Vulcan main engine based on the previous Ariane 5 design. But instead of the two solid rocket boosters used on the Ariane 5, the Ariane 6 is designed to have either two or four P120C strap-on solid rocket boosters attached depending on mission profile and payload

[00:14:39] mass. Now these P120C strap-on solid rocket boosters are also used as the core stage for ESA's new Vegas C launcher. That's where parts commonality comes in. The Ariane 6's upper stage is also fueled by liquid hydrogen and liquid oxygen, this time feeding a VINCI vacuum engine. Selected in December 2014 over an all solid-fueled alternative, the Ariane 6 was initially planned to be introduced back in 2020.

[00:15:05] However, the program faced a lot of ongoing delays, with the first launch eventually not taking place until July the 9th last year. Combined with the new Vegas C, Ariane 6 is providing the European Space Agency with its next generation of independent access into space. This report from ESA TV. Trucks arrive with the first and second stage of Ariane 6 at the launcher assembly building in Kourou.

[00:15:31] Here both stages are assembled horizontally before being transported to the mobile gantry for further integration. This is the process each Ariane 6 will go through. This simplifies the preparation process just as in a car factory assembly line. The new launch base for Ariane 6 on one side, the launcher assembly building and then the launch pad itself with the big mobile gantry. Here Ariane 6's boosters and

[00:15:58] fairing with payloads will be fitted. Europe's future launchers are becoming reality. Ariane 6, the development goes full speed ahead and now industry has started the production of the first 15 launchers in production today. On Vega C side, all engines are tested. Vega C is the new and enhanced version of Europe's lightweight launcher Vega. It will allow for an increased and versatile payload capacity

[00:16:25] from Kourou. The future of our transport capacity as such will depend on the number of technology breaks. So it's not about the idea of predicting what will be the overall system in 10 or 15 years from now. It is about replying to requirements. And some requirements are calling for new propulsion systems.

[00:16:52] This is why we put a first priority on propulsion systems, meaning engines. Engines for accessing space. And here it is important that we also take into account the reusable dimension of these engines. And for this we need to take into account the propellant. Like you can tank your car with gas oil or

[00:17:14] other propellants. We will now work on propellants which are, for example, methane-based, allowing to reuse these engines for access to space. Structure means material. Material means weight. So there is a big change that we are doing much more also

[00:17:35] in carbon fiber for different elements of the launcher which will automatically lower the overall weight. And if we lower, for example, one kilogram on the upper stage of a launcher, you have immediately one kilogram of wind for your payload, for your satellite.

[00:17:53] Today we are introducing in arian 6 and Vega C parts produced through ALM, 3D printing. Tomorrow we will have much more. So we are also investigating not only on what are the technology building bricks of tomorrow, but also how we will produce launchers and launch solutions, transport systems tomorrow.

[00:18:17] In parallel, ESA is supporting the development of a structure to launch multiple satellites called Small Spacecraft Mission Service. This dispenser allows more than a dozen small satellites to be launched under the fairing of Vega. And we are already now preparing the same for Vega C and Ariane 6. So all our European launchers, which are in development today, will have the capacity to offer a launch of a number of small satellites.

[00:18:47] Light satellites, light satellites. It's a real market enhancement. Another project for ESA is SpaceRider. It is the continuation of the intermediate experimental vehicle, IXV, the successful mission that flew in February 2015. SpaceRider is an unmanned orbital vehicle that should provide Europe with its first operational reusable space transportation system.

[00:19:11] It will be able to return from space and will allow for experiments in microgravity, in-orbit validation of technologies, deployment of small satellites and might even be used for Earth observation applications or servicing missions. We have today the access to space component, which is covered through Ariane 6 and Vega C.

[00:19:34] We are developing at ESA, STS, space transportation, also propulsion elements, engines for transport in space. And with SpaceRider, we have an operational capability, which will have to be decided in Sevilla, end of the year, for returning from space on Earth. Today, with its range of launch vehicles, Europe is already able to launch any type of satellite into any orbit.

[00:20:00] The new portfolio under development aims to further secure this approach on the commercial launcher market. And at the same time, ensures Europe's independent access to space in the future. And in that report from ESA TV, we heard from ESA's Director of Space Transportation, Daniel Neuenschwender. This is Space Time.

[00:20:36] And time now to take another brief look at some of the other stories making use in science this week with a science report. A new study suggests that the Dead Sea Scrolls may be even older than traditionally thought. The findings, reported in the journal PLOS One, are based on research by ENOC, an artificial intelligence trained on the handwriting styles of centuries-old manuscripts from the Middle East. ENOC is trained in the writing style of 24 ancient manuscripts that had previously been carbon dated.

[00:21:05] It was then asked to predict the age of 135 non-carbon dated scrolls. They then compared these predictions with traditional handwriting analysis of predictions of the Dead Sea Scrolls, and found that ENOC's estimate for the age of the scrolls was realistic in 79% of cases, and in most cases estimated a slightly older age for the scrolls compared to traditional analyses.

[00:21:27] The Dead Sea Scrolls are a collection of ancient Jewish manuscripts first discovered between 1946 and 1956 in caves near Qumran on the northern shore of the Dead Sea. The scrolls, which were inscribed at various times between 2,400 years ago and the 2nd century, offers invaluable insights into ancient Jewish religious practices, beliefs, and the history of the Hebrew Bible, the Torah, which is the basis for the Old Testament in today's Christian Bible.

[00:21:56] People on the autism spectrum often have difficulty sleeping. Now, a new study has shown that babies who sleep less are of poorer sleep quality, are often more likely to develop autistic traits, and subsequently end up being diagnosed with autism. The findings were reported in the Journal of the Archives of Disease in Childhood, based on a study looking at over 1,000 mother-infant pairings, focusing on the baby's sleep patterns at both 6 and 12 months of age.

[00:22:23] The authors then looked at the child's parent reported autism characteristics at ages 2 and 4 years. And by the time the children had turned 12, 64 of them had been diagnosed with autism. The authors say poor sleep quality as a baby was consistently linked to more autism characteristics and a later autism diagnosis. Now, while it's not clear exactly why this link exists, it means sleep issues could well be an early indicator of autism.

[00:22:52] A new study has unveiled the ward's first reported stomach contents of a seropod dinosaur. The findings, reported in the journal Current Biology, has allowed paleontologists to learn more about the feeding habits of one of the largest terrestrial animals that ever lived. Cerepods are those big, herbivorous dinosaurs with elephant-like bodies and feet, a long tail at one end and an even longer neck and small head at the other. Just think of Fred Flintstone's pet Dino.

[00:23:18] The authors analysed the fossilised stomach contents of a 95-year-old seropod, a Dimantinosaurus matilda specimen nicknamed Judy, which had been unearthed at the Woolton dinosaur fossil fields in outback Queensland in 2017. Scientists found pineals and bracts from tall conifer trees, along with leaves and fruiting bodies from smaller seed ferns and flowering plants in the animal's stomach.

[00:23:43] Apple's developers conference has shown off their translucent design update for iOS 26, known as Liquid Glass. The new refresh is Apple's first major interface overhaul in 10 years, and the software changes will be rolled out to the entire suite of Apple devices, from Macs and iPhones through to iPads and watches. With the details, we're joined by technology editor Alex Haralvoit from TechAdvice.life. The WWDC started off with a montage of Craig Federighi,

[00:24:11] the VP in charge of pretty much everything underneath Tim Cook, and also the new man in charge of AI. They started with AI and explained what they could do, and more or less apologised for the fact that they hadn't yet delivered the smartest Siri, the LLM chatbot-style Siri that everybody expects Apple to have had by now. But after we had that, we then launched into all of the updates for the iPhone, the iPad, Apple Watch, Vision Pro, Apple TV, and of course the Mac. And we now have this unifying glass theme.

[00:24:41] Now, this is just the first developer beta. Apple is going to be getting all the feedback and going to be tweaking everything for the next three months before launch. I've downloaded macOS 26 Tahoe, and so far, so good. And I've also downloaded the new operating system iOS 26 onto my spare iPhone 16 Pro Max. And just on basically first impressions, little bugs here and there. Of course, it's a very early dev beta, but it's looking good. Things are working well so far.

[00:25:09] I haven't really come across any major glitches, but my secondary phone, not my primary phone, so I haven't gone through every single scenario yet. And also, this is obviously not something that you, as a member of the public, should be installing at this early stage. There will be a public beta in July. And if you are brave and you want to do it, that's the time to do it. But yes, this is Apple using its two plus billion user base to upgrade them to a much more consistent experience across all the devices.

[00:25:38] And the iPad OS 26 now has resizable windows. It has a menu that can appear at the top of the screen when you either swipe down or put your cursor there. The round dot cursor that has plagued iPads and iPhones for years, if you tried to connect a mouse or a trackpad to it, is now an arrow, at least on the iPad. I haven't tried it on my iPhone yet. But we are seeing the beginnings of what Apple is going to inevitably launch, in my eyes anyway, as a Mac pad device.

[00:26:06] That is Mac and iPad all in the same unit. I mean, they're so close to it. There's nothing stopping any of the hardware from running Mac apps. The only limiting factor that I can see is Apple, just not offering that capability yet. But Apple doesn't want to offer that capability until they're ready. And bedding down this new operating system for iPads that can have the windows that you expect from a Mac or from a Windows PC is a huge part of that. One of the cool things I saw straight away with Mac OS 26 Tahoe is that if you have your system in dark mode

[00:26:34] and you open up a PDF, which is normally a white page with black text blaring into your eyes because you're used to dark mode, you can now switch that PDF to dark mode. What a revelation. Why didn't I do that before? I don't know, but it is possible now. And on the surface thus far, I'm very impressed. We're going to see a lot more changes and tweaks over the next three months. And then, of course, the new iPhones and new iPads and new devices will come in September, October, where there will be more surprises. And in other news, Android 16 has also dropped.

[00:27:02] And people are saying, well, the Android 16 interface for the pixels, and it'll come to all the other Android devices later, is actually a more polished interface than iOS and the 26 versions of, you know, the year 26 versions of all of Apple systems. But Android is ready to be released. Apple is still in the developer phase, don't even have a public media yet. But the big war between all the companies continues. The fight for AI supremacy continues. Apple is working on giving you useful AI features that are going to make your life better in the short term, whilst they're working on an LLM chatbot version of Siri.

[00:27:32] And I guess this sets up a very exciting 2026 WWDC as well. Everyone expect big changes to your iPhone in about three months. And I suspect you're going to love it. That's Alex Zahar of Roy from techadvice.life.

[00:27:46] And that's the show for now. Space Time is available every Monday, Wednesday and Friday through Apple Podcasts, iTunes, Stitcher, Google Podcasts, Pocket Casts, Spotify, Acast, Amazon Music,

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