Martian Mysteries and Stellar Journeys: Unveiling the Red Planet's Thermal Anomaly

This is Space Time, Series 29, Episode 104, for broadcast on the 31st of August, 2026. Coming up on Space Time, the strange anomaly discovered under the Martian South Pole. Starship 40 finally leaves Australian waters bound for home. And the final countdown now underway for NASA's Roman Space Telescope. All that and more coming up on Space Time. Welcome to Space Time with Stuart Gary. Astronomers have discovered a strange thermal anomaly deep beneath the surface of the Martian Southern Hemisphere. The findings suggest the red planet's southern interior is somewhere around 200 to 400 degrees Celsius warmer than the planet's northern hemisphere, and it's still partially molten. The surprising findings reported in the journal Nature add context to Martian history and the periods during which it may have hosted conditions favourable for life as we know it. The study's lead author, Alexander Byrne from Caltech and the University of Arizona, says understanding the interior structure of planetary bodies helps scientists unravel the processes that shape their formation and evolution. The new findings are based on a model developed by Byrne using variations in gravitational data to infer the internal structure of a planetary body. Byrne and colleagues then applied this model to the Martian interior, using data collected over decades from three different Martian orbital missions, Global Surveyor, Mars Odyssey and the Mars Reconnaissance Orbiter. The authors measured tiny variations in the spacecraft's velocities and then used that to reconstruct the gravitational field around Mars. The gravitational forces exerted by the Sun on Mars vary over seasonal timescales. That's due to the planet's slightly elliptical orbit and its tilted rotational axis. So a technique called tidal tomography can measure how these gravitational signatures vary over time, allowing astronomers to produce a model of the planet's interior. Byrne says scientists usually assume that the interiors of planetary bodies are generally spherical and symmetric, but that's not necessarily the case. He says as you get more gravity data, you can start to determine the three-dimensional intricacies of a planetary interior. On the surface, Mars is a geologically asymmetrical planet. Its southern hemisphere contains towering mountains and deep craters, whereas the northern hemisphere is composed of low-lying flatlands, the dry remains of a once planetary ocean. The new observations also suggest explanations for other phenomena observed on the red planet, such as magnetic anomalies found in iron minerals in the south. A thermal anomaly in the southern mantle could mean that a magnetic field existed that was strong enough to cause magnetic differences between the north and south. And of course, don't forget NASA's InSight mission had previously discovered seismic waves dissipate more quickly in the south, which could be explained if that region's hotter. Mind you, it's still unclear what created this thermal dichotomy, and there are several hypotheses for its origins, including a giant impact releasing heat from the north, past spontaneous convection in the Martian southern hemisphere, and thick geological features trapping excess heat from escaping. Only time and a more detailed exploration of the red planet will tell. This is space time. Still to come... Starship 40 finally leaving Australian waters bound for Texas. And the final countdown now underway for the launch of NASA's new Nancy Grace Roman Space Telescope. All that and more still to come on Space Time. Starship 40 has finally left Australian waters bound for home. The orbiter used for SpaceX's test flight 13 has been loaded onto the 48,000-ton semi-submersible vessel Forte for the long journey back to Starbase, Texas. The 52-metre-long spacecraft splashed down in the Indian Ocean off the western Australian coast back on July 25 following a successful test flight. The mission was only the second flight for the Starship and Super Heavy Block III vehicles. The flight test began with Super Heavy igniting all 33 Raptor III engines and blasting off from the Boca Chica launch pad at Starbase, Texas, climbing high into blue skies over the Gulf Coast. The successful first stage ascent was followed by a hot staging maneuver, with Starship's upper stage igniting all six of its Raptor engines to continue its flight to orbit. Following stage separation, the Super Heavy booster performed its boost backbone and flip maneuver to return to Earth. and the ignition sequence for this was modified this time in order to provide a more robust timing variability in engine startup and flip to the desired direction. The Super Heavy booster then successfully descended, completing the high-thrust portion of its boost-back burn with all 33 Raptor engines firing, before ending the burn early and letting the Earth's atmosphere do the work. However, only 10 of the Plan 13 Raptor engines lit up for the landing burn, with two of those engines failing shortly afterwards, resulting in an unusually heavy splashdown in Gulf waters. Meanwhile, Starship successfully continued its journey to orbit, deploying 20 Starlink Version 3 test satellites before undertaking a restart of one of its Raptor engines. It then re-entered Earth's atmosphere above the Indian Ocean, successfully gathering critical data on the performance of its heat shield before executing a dynamic banking maneuver to practice the sort of trajectories needed for future missions returning to Starbase. Starship then guided itself using its four flaps to the pre-planned splashdown zone 1,300 kilometers west of Dampier. After reigniting three Raptor engines, Starship successfully executed a landing flip, its landing burn, and a soft splashdown, coming to rest intact on the surface of the Indian Ocean. But instead of sinking as expected, it remained intact, bobbing up and down in the warm tropical swell. And its unexpected survival provided a unique opportunity for SpaceX to gather crucial data of an intact heat shield for the first time. After a survey by SpaceX's splashdown monitoring ship Go Australis, the company worked with the Australian Space Agency on a recovery operation, using two ocean-going tugs, Norman Ranger and Skimmer Tide, to tow the 200-ton spacecraft back to shore. However, with the empty 200-ton spacecraft sitting high in the water, current and wind conditions eventually led to the abandonment of the initial plan to tow east to Dampier. And instead, Starship was taken north to Christmas Island, eventually arriving in sheltered waters in the island's Flying Fish Cove. The semi-submersible ship Forte then arrived a few days later, flighting its ballast tanks to submerge enough to allow Starship to be floated into position above its deck. It then emptied those ballast tanks and refloated, lifting the spacecraft out of the water for transport back to Texas. The 13,000 kilometre journey back to Starbase should see the spacecraft arrive in late September or early October. And needless to say, we'll keep you informed. This is Space Time. Still to come, the final countdown for NASA's new Roman Space Telescope and later in the science report. A new study shows that smoking rates have continued to drop in Australia while vaping rates are continuing to climb. All that and more still to come on Space Time. Music The final countdowns are underway for the launch of NASA's new Nancy Grace Roman Space Telescope. The mission will fly aboard a SpaceX Falcon Heavy rocket from the historic Space Launch Complex 39A at the Kennedy Space Center at the Cape Canaveral Space Force Base in Florida. That's the same launch pad where Apollo 11 was launched on the first manned mission to the lunar surface. Named after NASA's first chief astronomer, the mother of the Hubble Space Telescope, the Nancy Grace Roman Space Telescope will help settle essential questions about some of the most interesting topics in astronomy. After launch and stage separation from its launch vehicle, Roman will travel to the Sun-Earth Lagrangian L2 position, about 1.5 million kilometers away on the nighttime side of the planet. Roman has a five-year primary mission, with the goal of operating for at least 10 years. The telescope spaced around one of two spare Keyhole spy satellites given to NASA in 2012 by the National Reconnaissance Office. These spacecraft were being stored in a special clean room in upstate New York and were surplus to needs at the time. They're generally similar in design to the Hubble Space Telescope. Hubble is also based on the Keyhole spy satellite, but was modified to look up into deep space instead of down onto the Earth's surface. However, these two donated satellites have shorter focal lengths and hence wider fields of view than Hubble. That means Roman will have a field of view at least 100 times larger than Hubble's, potentially measuring light from billions of galaxies. It's crisp, sweeping surveys will help astronomers investigate dark energy and dark matter, discover and map billions of galaxies, study black holes, and explore objects from our own solar system right to the very edge of the observable universe. The telescope will also be able to block starlight, allowing it to directly see exoplanets and planet-forming disks. It will help complete a statistical census of planetary systems in our own galaxy, and it will settle essential questions on infrared astrophysics. This report from NASA TV. Observatories like the Webb and Hubble Space Telescopes are transforming our understanding of the universe. They have revealed that black holes are common, helped measure the age of the cosmos, and even played a key role in one of astronomy's greatest surprises, the discovery that the universe's expansion is accelerating, driven by an unknown force we simply call dark energy. But some of the biggest questions in science remain unanswered. What actually is dark energy? What is dark matter? How common are planetary systems like our own? And how did the universe evolve from the first isolated galaxies into the cosmic web we see today? NASA's Nancy Grace Roman Space Telescope is designed to help answer those questions. Roman will carry a mirror the same size as Hubble's, 2.4 meters across, but its true power comes from something entirely different. Its wide-field instrument will allow Roman to see enormous portions of the sky at once. A single Roman image will capture an area a hundred times larger than Hubble's or Webb's infrared views, while still delivering high resolution and sensitive observations. Roman does this with a unique array of 18 4K detectors. They are arranged in an arc to make full use of the optical system's region of best image quality. Combined, they form a 300-megapixel image. That combination of power and scale changes what is possible. Instead of studying a few objects at a time, Roman will survey vast regions of the universe. During its first five years, it is expected to observe more than a billion galaxies and collect data that would take centuries for other observatories to gather. One of Roman's primary goals is investigating dark energy. More than a century ago, Albert Einstein's equation suggested the universe should either expand or contract. In 1929, Edwin Hubble confirmed that galaxies are moving away from one another, showing that the universe is expanding. For decades, astronomers assumed gravity would gradually slow that expansion. Then, in 1998, observations of distant exploding stars revealed something unexpected. The expansion of the universe is speeding up. Something appears to be pushing the cosmos apart. Scientists call that unknown influence dark energy. Today, dark energy is thought to account for roughly 68% of the universe. Yet its true nature remains one of the greatest mysteries in physics. Roman will approach this problem using multiple independent techniques. It will map the positions of millions of galaxies in three dimensions, study distant supernova explosions, and measure how light bends through a phenomenon known as gravitational lensing. Together, these observations will allow scientists to trace how the universe has changed over billions of years and test whether dark energy has remained constant or evolved over time. ROMAN will also help illuminate another cosmic mystery. Dark Matter Although invisible, dark matter exerts a gravitational pull and appears to make up most of the matter the universe is made of. Astronomers can infer its presence because galaxies and galaxy clusters behave as though they contain far more mass than we can see. Something is there. Roman will map both visible matter and dark matter across enormous stretches of space by measuring small changes in the shapes of distant galaxies. These measurements will provide one of the most detailed views ever created of how matter is distributed throughout the cosmos and how large objects like galaxies evolved over cosmic history. Closer to home, Roman will also conduct one of the most ambitious searches for planets beyond our solar system. Most exoplanets discovered so far have been found using the transit method, which detects tiny dips in starlight when a planet crosses in front of its host star. Roman will complement those discoveries by primarily using a technique called gravitational microlensing. When a star passes in front of a more distant star, gravity bends and magnifies the background starlight. If a planet is orbiting the foreground star, it leaves a distinctive fingerprint in that signal. By continuously monitoring millions of stars in the crowded center of the Milky Way, Roman is expected to discover thousands of new worlds, including planets smaller than Mars, planets orbiting far from their stars, and even rogue planets drifting freely through space. These discoveries will help astronomers build the most complete census yet of planetary systems throughout our galaxy. Roman will also carry a coronagraph instrument. a technology demonstration designed to block the overwhelming glare of nearby stars. This will allow astronomers to directly image giant exoplanets and dusty disks around neighboring stars, helping pave the way toward future missions capable of finding Earth-like worlds. Beyond its primary investigations, Roman's vast surveys will become a treasure trove for astronomy. The mission is expected to discover some of the earliest galaxies in the universe, uncover distant quasars powered by supermassive black holes, reveal streams of stars swirling into nearby galaxies, and provide an unprecedented map of the cosmos, stretching back to when the universe was only a fraction of its current age. Many of the most important discoveries may be things astronomers aren't even expecting to find. That's because Roman is designed not just to study individual objects, but to reveal the bigger picture. The phenomenon Roman will detect in its wide-field images will be followed up with detailed, higher-resolution studies by Hubble and Webb, which together cover wavelengths of light ranging from ultraviolet to mid-infrared. Along with observatories like Hubble, Webb, ESA's Euclid mission, and the VeriC-Rubin Observatory, Roman will usher in a new era of discovery, giving scientists an unprecedented view of the universe and bringing us closer to answering some of humanity's oldest questions. What is the universe made of? How did it become what we see today? And what will its ultimate fate be? The Nancy Grace Roman Space Telescope was built to help us find out. This is space time. And time now to take a brief look at some of the other stories making use in science this week with a science report. Researchers have set a new record for keeping brain organelles alive, maintaining them for more than five years. A report in the journal Nature says the organelles, which mirror the development of human brains, didn't just survive for five years, they continue to change, develop and mature over time. The cells showed gene expression changes similar to those that take place in the brains of fetuses and newborns, and occurring at around the same pace. And the cells from old organoids that were mixed with the fresh batch seemed to retain a memory for their age and function, making neurons more suitable for an older brain rather than their new situation. A new study has shown that smoking rates have continued to drop in Australia, while at the same time, vaping rates have continued to climb. The findings by the Australian Institute for Health and Welfare's National Drug Strategy Household Survey looked at over 17,500 people aged 14 and older, showing that 5.6% of the population was smoking daily in 2025. That's down from 8.3% in 2022-23 and the lowest rate since the survey began. However, the news isn't all good. e-cigarette smoking rates have continued to increase, but far more slowly compared to sharp rises in recent years, with daily use at 3.6% in 2025, up 0.1% from the 2022-23 figure. There are new warnings today that Australia's native reptiles are disappearing at almost twice the rate previously thought. The findings, reported in the journal Pacific Conservation Biology, show native lizards and snakes are facing a far more precarious future than previously understood, with around 127 species, or just over 13%, now likely to be threatened with extinction. The new research by Monash University brings together leading reptile experts from across Australia to assess the progress since the landmark 2017 Action Plan for Australia's Lizards and Snakes. A new study has found that dogs may be communicating with you through their blinking. The findings reported in the Journal of the Royal Society of Open Science studied canine reactions to videos of people blinking or keeping their eyes open. They found dogs increased their blinking when they were watching humans blink, but only if they knew the person, and also they tended to blink more at familiar females than males. Now exactly what dogs are trying to communicate through blinking remains unclear. but the findings suggest that it may be playing a role in doggy sexual behaviour. It's been revealed that the South Australian government ordered bureaucrats to downplay the state's deadly algal bloom outbreak, which began poisoning coastal waters back in March 2025. The unprecedented ecological disaster is estimated to have caused the death of millions of marine animals, affecting an incredibly broad cross-section of the ecosystem. Over 600 distinct species were impacted, including large numbers of dolphins, King George whiting, southern calamari, western king prawns, abalone, sharks, rays, seahorses and dragons, as well as crabs and lobsters. Further up the food chain, seabird populations were also impacted, with huge numbers of severely emaciated dead birds collected from beaches after starving to death. The South Australian Marine Mortality Events Project on iNaturalist formerly logged tens of thousands of individual dead animals washing ashore. However, despite the enormity of the tragedy, internal government emails from the Department for the Premier and Cabinet showed public servants were ordered to remove words such as harmful, outbreak and disaster from public communications about the blooms. The sceptic's Tim Mendham says the orders to downplay the disaster were released under freedom of information laws. Sounds more serious than it is, like a government conspiracy. I would say it's more a PR exercise. These are stories that appear in newspapers, websites. There was even one described as an advertorial, which is a paid editorial, that was going in about what was happening. And the people who were writing them were advised not to use words harmful, outbreak, and disaster, because it gave them sort of a people-worrying approach. Everybody commenting on it said, it is harmful, it is an outbreak, it is a disaster, yeah, probably. It's a PR thing. Government marketing department saying, well, you can't scare the chooks, right? You can't sort of upset people. But it's a worry that people are getting paid taxpayer money to lie to them. Yes, and it's what marketing departments do. Whether it's a private one being paid by a company to downplay a problem, or whether it's a marketing department within a government department saying, oh, well, let's make this softer and nicer. It's still the same problem of people lying. Yes, it's unfortunate they have taxpayer money. But I mean, I wouldn't see it as a government conspiracy. I'd see it as a well-intentioned, idiotic move by some person in marketing saying, don't write scary things in your stories. Even the Premier of the state said, That can't be right. I and other senior members of the government have been very clear about the fact that the algal bloom is harmful. So it's not high level government. It's someone lower down saying, you write a press release, you write an article, don't make it sound too scary. Which is wrong because it is scary. And that honesty didn't hurt him in the election. He won re-election. That's right. He won quite clearly. If you're in a company and you've got a scandal, own up to it straight away. Don't pretend it never happened. Don't downplay it. If it's a serious thing, you own up to it and say, sorry, mistake. Because if you try and hide something, like saying something's not harmful. That becomes a story. It becomes a story, yeah. It becomes a story, like in this case. Ask Richard Nixon. Yes. You hide a story, it's going to come out. Sure as eggs. And therefore, don't hide the story. Don't say it's not harmful when it is. That's the Skeptic's Timendum. And this is Space Time. And that's the show for now. Space Time is available every Monday, Wednesday and Friday through Bytes.com, SoundCloud, YouTube, your favorite podcast download provider and from spacetimewithstuartgarry.com. Space Time is also broadcast through the National Science Foundation on Science Zone Radio and on both iHeart Radio and TuneIn 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 bonus audio content which doesn't go to air, access to our exclusive Facebook group, and other rewards. 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