Cosmic Threads: Discovering the Universe's Hidden Matter in Hot Gas Filaments

[00:00:00] This is Space Time series 28 episode 76, broadcast on the 25th of June 2025. Coming up on Space Time, astronomers find the universe's missing matter, more concerns about leaks aboard the International Space Station, and the European Space Agency rolls forward with its new Mars rover. All that and more coming up on Space Time. Welcome to Space Time with Stuart Gary.

[00:00:43] A new study has confirmed earlier observations that suggest the universe's missing normal matter is hidden in hot intergalactic gas filaments. These filaments are a key part of the intricate cosmic web-like structure of the universe, which is made up of strings of galaxies, galaxy clusters and superclusters surrounding vast, near-empty voids.

[00:01:04] Now, a report in the journal Astronomy and Astrophysics is detailing further support for this hypothesis, with the discovery of a huge filament of hot gas, ten times as massive as the Milky Way, bridging four huge galaxy clusters. The study's authors made the observations using the European Space Agency's X-Men and Jax's Suzaku X-ray space telescopes.

[00:01:26] Over a third of the baryonic, so-called normal matter in our local universe, the visible stuff making up stars, planets, galaxies, houses, cars, trees, dogs, cats and people is missing. While it hasn't been seen, it must be there, because it's needed to make science's models of the cosmos work properly. Now, these models suggest that this elusive matter may well exist in long strings of gas or filaments, bridging the densest pockets of space.

[00:01:51] While astronomers have spotted such filaments before, it's always been tricky to make out their properties. They're typically very faint, making it difficult to isolate their light from that of nearby galaxies and black holes. And that's where this new research comes in. It's one of the first to make this observation successfully, finding and accurately characterising a single filament of hot gas stretching between four clusters of galaxies in the nearby universe.

[00:02:17] Studies lead author Konstantinos Migas from the Leiden Observatory in the Netherlands says that for the first time, the results closely match what astronomers are seeing in their leading models of the cosmos. And that's something that's not happened before. He says it appears the simulations were right all along. Clocking in at over 10 million degrees, this filament of gas connects four galaxy clusters, two at one end and two at the other.

[00:02:42] All are part of the Shapley supercluster, a collection of more than 8,000 galaxies which form one of the most massive structures in the nearby universe. The filament stretches diagonally away from us through the supercluster for some 23 million light years. That's the equivalent of traversing the Milky Way end to end around 230 times. Migas and colleagues characterised the filament by combining X-ray observations from XMM Newton and Suzuki and digging into optical data from several other telescopes.

[00:03:11] He says the two X-ray telescopes were ideal partners for the research. Zizuka mapped the filament's faint X-ray light over a wide region of space, while XMM Newton pinpointed very precisely contaminating sources of X-rays, namely supermassive black holes lying within the filament. So thanks to XMM Newton, the authors could identify and remove these cosmic contaminants. So they knew what they were looking at was the gas in the filament and nothing else.

[00:03:37] As well as revealing a huge and previously unseen thread of matter running through the nearby cosmos, the findings show how some of the densest and most extreme structures in the universe, galaxy clusters, are connected over colossal distances. And so it also sheds light on the very nature of the cosmic web itself. Piecing together an accurate picture of the cosmic web is the domain of ESA's Euclid mission. Launched in 2023, Euclid is exploring the web structure and history.

[00:04:05] The mission is also digging deep into the nature of dark matter and dark energy, neither of which have ever been observed, despite accounting for more than 95% of the total mass energy budget of the universe. This is space time. Still to come, more concerns about leaks aboard the International Space Station and ESA rolls forward with this new Mars rover. All that and more still to come on space time.

[00:04:45] Fresh concerns about leaks aboard the International Space Station have delayed the SpaceX Axiom Space Flight 4 mission to the orbiting outpost. The 14-day mission aboard a Dragon spacecraft from the Kennedy Space Center in Florida will transport a crew of American, Indian, Polish and Hungarian astronauts. The launch had already been delayed by both bad weather and technical issues with the Falcon 9 booster. Now NASA has put a further hold on the flight so that it can monitor cabin pressure aboard the Russian side of the space station,

[00:05:15] which has again been venting atmosphere into space. The Russian Federal Space Agency at OzCosmos has been dealing with ongoing structural cracks and air leaks within its modules for more than five years. In fact, NASA are describing these continuing problems with the Russian segment as a top safety risk. The latest leaks have been narrowed down to the Zvezda module, and Russian cosmonauts have been inspecting the internal bulkheads of the module and looking at possible problems with some of the connecting nodes.

[00:05:41] They now think they've isolated this latest leak and have sealed it successfully. And NASA says the repairs appear to have worked, with the section now appearing at least to hold pressure. But the delay to the Axiom 4 mission will provide extra time for NASA and OzCosmos to evaluate the situation in more detail and determine whether further repairs are needed. Meanwhile, the four Axiom space flight astronauts are remaining in quarantine in Florida for the moment, pending a new launch window.

[00:06:07] Meanwhile, the crew aboard the International Space Station have successfully undertaken a planned orbital correction manoeuvre. See, over time as the space station orbits the Earth, atmospheric drag causes it to slowly lose altitude. So every now and then, the space station needs to be boosted back up into a higher orbit. They used to be done by visiting space shuttles. But since the premature demise of the space shuttle program, the job has been taken over by visiting Russian cargo ships.

[00:06:35] And so this week, mission managers fired up the engines of the Russian Progress 30 cargo ship, which is currently docked to the space station. Progress 30 undertook a 208.4 second burn, enough to push the space station with an impulse of about 0.3 metres per second back up to an orbital altitude of 416.18 kilometres. This is space time. Still to come, ESA back on track rolling forward with its new Mars rover.

[00:07:02] And later in the science report, a new study has shown that conversion therapy is not just psychologically dangerous, but biologically unhealthy. All that and more still to come on Space Time.

[00:07:28] The European Space Agency's ExoMars rover, the Rosalind Franklin, is now back on track and expected to land on the red planet in 2028, some seven years later than originally planned. The Rosalind Franklin was the second part of a two-phase multinational project by ESA and the Russian Federal Space Agency Roscosmos to study the red planet. The goals of ExoMars were to search for science of past Martian life, investigate how the Martian water and geochemical environment of the red planet varies,

[00:07:58] examine atmospheric trace gases and search for their sources, and by doing so, demonstrate the technologies for a future Mars sample return mission. Now the first part of this program launched the Mars Trace Gas Orbiter to the red planet back in 2016. Trace Gas Orbiter deployed the Shepirelli lander. It was meant to descend down to the planet's surface, landing on the Meridiani planum. Trace Gas Orbiter proceeded to map the sources of methane and other trace gases present in the Martian atmosphere,

[00:08:27] which could be evidence of either geological or possibly even biological activity. Trace Gas Orbiter features an array of scientific instruments and also acts as a communications relay satellite, transmitting surface operations back to Earth. As for the Shepirelli lander, it was designed to test new key technologies to safely deliver the subsequent Rosalind Franklin rover mission down to the Martian surface. However, while the orbit is still successfully working starting the red planet from orbit,

[00:08:53] Shepirelli fell during its descent, crashing into the surface. Now the second part of the ExoMars program was planned to launch in July 2020, when the Russian Kazuchok or little Cossack lander was meant to deliver the Rosalind Franklin rover to the Martian surface. However, ongoing problems with the development of the Russian lander repeatedly delayed the mission. Then in March 2022, the European Space Agency suspended the mission altogether following Moscow's invasion of Ukraine. Finally, in April 2024,

[00:09:24] the mission was revived after it received new funding from ESA to restart the development and delivery of the Rosalind Franklin rover and with NASA now agreeing to provide launch services. This report from ESA-TV. The ExoMars missions began in 2016 with the successful launch and deployment of the Trace Gas Orbiter. This first ExoMars spacecraft is now nicely orbiting around Mars.

[00:09:49] It's fulfilling very well its scientific mission and it has proven as well its capability to relay data from Mars assets to the Earth and we use for that the American rovers. This proven capability will be needed to communicate with Europe's first Mars rover, Rosalind Franklin. A landing site in an area called Oxiaplanum has been recommended for this joint Eastern mission, which has four elements.

[00:10:17] We have a carrier module to push the spacecraft to Mars. We have a descent module to bring the landing assets, the rover for the European and the landing platform down to Mars. And we have the rover, which is the main interest of the Europeans into the mission. This rover carries nine payload instruments that will fulfill basically the main mission to discover traces of life on the planet. The rover, which was built at Airbus UK, is now undergoing final tests in Toulouse, France.

[00:10:48] And in that report from ESA-TV, we heard from ESA ExoMars team leader, Francisca Spotto. Now with its new 2028 launch deadline, ESA is once again working to produce a workable Rosalind Franklin rover, testing it under a range of different Martian conditions and terrains. The project's been putting a full-size model of the rover through its paces and a series of tests designed to fine-tune how the rover will move from its landing platform down to the Martian surface and then how it will explore the Martian world beyond.

[00:11:17] See, the thing is, rovers on Mars have previously been caught in sand and turning the wheels simply dug them in deeper, just like a car stuck in muddled snow. To avoid this, the engineers behind the Rosalind Franklin rover have developed a unique locomotion mode known as wheel walking. This is a dedicated facility where it simulates all what we expect to see and we want to test in terms of performances on Mars. The arrangement here is a set-up we have to perform egress tests.

[00:11:43] Actually, what we're testing in this period is different configurations of slope and orientations of the lander and the rover. In reality, what will happen is that the rover will land encapsulated in the platform. Then it will unfold the wheels and the ramps will be deployed. This is a very delicate and potentially dangerous operation. We want to account for any adverse situation, for example landing on the foot of a small hill which has a lander tilted.

[00:12:14] Or landing when our ramps open, we have an obstacle on one of them or one of another ramp lands on an obstacle so you have to egress in a tilted configuration. Now the test platform is tilted 5 degrees. We are simulating what the rover might encounter when it lands on Mars. We are increasing the level of difficulty of this test. Before we went for 5 degrees. Now we are moving up to 15 degrees.

[00:12:39] The rover has to overcome obstacles which have a height of at least 250 millimeters. There are pyramidicals, round or square ones. And we will test to overcome one or several in different inclinations. Without the flow-manguators being strong enough, we can implement an additional locomotion mode which we call wheel walking, which articulates a motion.

[00:13:09] And this motion gives very good traction capability in very soft soils and in very high slopes. Eventually we will be able to go to places to find interesting elements on the surface of Mars and basically achieving the intended operations and the return in terms of science. We are on track for Mars. We plan to complete this test basically as planned with some minor glitches here and there. We will then continue with further, more elaborated tests.

[00:13:37] Many other tests are taking place across Europe to get the rover ready for Mars. While the flight model takes shape, science instruments are carefully installed and the software runs all possible scenarios to guarantee a good performance on the red planet. And in that report from ESA TV, we had from ESA ExoMars rover mobility systems engineer, Pantelis Polakis, ESA spokesperson, Agida Vincente, RUAG locomotion verification systems manager, Boris Holter,

[00:14:06] and Airbus locomotion verification model architect, Jesus Quince Garcia. This is Space Time. And time now to take another brief look at some of the other stories making news in science this week with the science report.

[00:14:33] A new study has shown that conversion therapy, that's where kids are encouraged, often forced to appear to change their true sexual orientation and gender identity, is not just psychologically damaging, which has been proved in previous studies, but is also biologically unhealthy and linked to higher blood pressure and inflammation. A report in the Journal of the American Medical Association found that this link was still strong, even when the researchers accounted for a range of outside factors, such as demographics, health behaviours and HIV status.

[00:15:03] They found that most of the 72 study participants who had been exposed to conversion therapy said the experience affected them very negatively. And so researchers suspect that the blood pressure increase has something to do with the release of the stress hormone cortisol. Archaeologists from the Australian Museum have unearthed 693 First Nations stone artefacts, some of which date back to the last ice age. The artefacts were found in an ancient Blue Mountain cave known as the Dagon Shelter.

[00:15:32] The findings reported in the journal Nature Human Behaviour are new evidence providing definitive proof of the repeated occupation of this once frozen high altitude landscape. Engineers say a new filter for infrared light could see scanning and screening technology tumbling price and size. A report in the journal Laser and Photonics Reviews says the new heat-tutable filters are built on nanotechnology

[00:15:56] and promise hand-held robust equipment which can replace the current generation of desktop infrared spectroscopy setups that are bulky, heavy and can cost from $10,000 to more than $100,000. Because the new instruments will be built on silicon chips, the manufacturing can be scaled down with the potential to push costs down to below a dollar per filter. Apple have finally rolled out some long-awaited new features for its iOS 26 update,

[00:16:23] which will finally offer its users what's already available on other cell phones. With the details, we're joined by technology editor Alex Saharov-Royt from TechAdvice.live. One of the features on iOS 26 is going to be call screening and call holding. And that's something that Google Pixel users have had for years, but it's going to become standard. This is something that's going to be a real quality of life improvement. I mean, normally when you get an updated phone, you normally are not talking about the phone call part of the equation. It's about how good the camera is and how much memory it's got

[00:16:52] and what are the other new features for AI. But in this case, it's using some AI features to deliver call holding and call screening. So if you get a phone call and it's from a number that is new to you or you haven't saved it into your contacts, the iPhone will answer the call for you and it will ask the person, well, what are you calling about? What is it you'd like to get this person's attention for? And so that person then has to explain what it is they want to tell you. And then after that, the phone will ring and you'll be told or you'll be seeing on the screen

[00:17:22] what it is they want to talk to you about. And then you can talk to them. And obviously, if it is some sort of salesperson trying to get you onto a new electricity bill, well, you can just ignore it. Then the other big problem of the modern age is having to call your bank or an airline or some utility and then being stuck on hold for half an hour, an hour, however long it takes. And what the system will do is it will go on hold for you. It will allow you to stop listening to the hold music. It will then answer the call when the person comes on the line to take your call and say, okay, this is the iPhone system.

[00:17:51] I'm just going to contact the person calling you right now. Hang on. Please don't hang up. Then the phone will ring and suddenly you're talking to the customer service agent and that's going to free up a lot of time. You can do other things. You can put your phone down, not have to be listening to this repetitive, boring hold music about how your call is important to us. And again, these are things that Google Pixel owners actually have enjoyed for some time. And I've been wondering when this would come for iPhones and many iPhone users will be able to enjoy this from September later this year

[00:18:19] when they launch the final versions of the new system. The other big news has been the latest with Telstra and its satellite communication system. What's happened there? Yeah, so they launched it to be compatible initially with the Galaxy S25 range of Samsung smartphones. And then the weekend after that launch, they announced a whole series of iPhones were also now compatible. Now, the important thing is, and people have said to me, oh, does this mean I can send it via satellite when I'm in a room of the house or somewhere, you know, on my property that doesn't get service?

[00:18:48] And it's like, no, it's not designed to be used in areas where you should have mobile reception. For that, you can use Wi-Fi calling or you can call over WhatsApp or FaceTime, some sort of other system. But this is for when you are specifically outside of Telstra's mobile range. The phone will then say Telstra SpaceX and you can send a message to anybody, including emojis. And Telstra announced that within the first 10 days of that feature being switched on, over 1 million text messages were sent and received. But the fact is it works.

[00:19:17] And we should see Australia's other two big carriers announce similar capabilities at some point. And we already have this happening in the US. So this is shrinking the tyranny of distance. And later this year, you'll be able to do phone calls and data as well. So yeah, ubiquitous communications is a reality that's getting ever closer and nearer. So for now, this is just SMS? Just SMS for now, just text messages. You can't, as far as I'm aware, send any images because that would require data. And also it's not instant. You've got to hold your phone up and make sure the satellites are overhead.

[00:19:45] It's a bit like the emergency SOS messages that were sent before through iPhones, but only to emergency services people. Now you can send a message to anybody. And that can be very handy if you're broken down and there's no cars driving by and you need to contact someone to say, Hey, get the NRMA or the equivalent car assistance, roadside assistance. The auto club. The auto club. Yeah, absolutely. That's Alex Zaharov-Royt from techadvice.life.

[00:20:08] And that's the show for now.

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