This is Space Time, Series 29, Episode 129, for broadcast on the 20th of October, 2026. Coming up on Space Time... The giant Valleys Marinaris Canyon on Mars still tectonically active. Our incredibly shrinking Moon. And when was Van Gogh's famous painting, The Starry Night, actually painted? All that and more coming up on Space Time. Welcome to Space Time with Stuart Garry. A new study claims the solar system's largest canyon, the Valles Marinaris, is still active and reshaping the red planet Mars today. The gigantic rift system forms a more than 4,000 kilometre long scar across the Martian surface, just south of the red planet's equator. The canyon is huge, up to 600 kilometres wide, and it plunges down some 9 kilometres deep. That makes Valles Marineris nearly 10 times longer, 5 times deeper and 20 times wider than America's famous Grand Canyon. But unlike the Grand Canyon, which is primarily carved by a river, Valles Marineris is a massive tectonic rift. It formed billions of years ago as the Martian crust cracked and stretched under immense stress from the rising Tharsis volcanic bulge. The new research, reported in the journal Nature Communications, is based on seismic data from NASA's InSight lander, which shows that a mass quake originated beneath the vast canyon system. It shows the quake was caused by the surface lithosphere slipping along a fault line deep within the planet's crust. The study's lead author, Yonghun Song from Imperial College London, says until now, scientists didn't know for certain that its faults were still active. The clue came when Song and colleagues studied a seismic event known as S0976A, recorded by InSight back on August 25th, 2021. The event was unusual because it originated from the vicinity of the western Valles Marineris, on the opposite side of Mars to where the lander was, making it the only mass quake ever detected from the planet's western hemisphere. While mass quakes can be created by seismic activity, they're also often caused by meteor impacts or landslides. So getting a signal doesn't necessarily mean that a fault is ruptured. To determine the signal's origin, the authors analyzed how different seismic waves from the event traveled through Mars to reach InSight. They found the best explanation was a strike-slip mass quake, in which blocks of crust moved horizontally past one another along a steep, deeply rooted fault roughly 20 to 40 kilometers below the surface. As to the origin, well, unlike Earth's continually moving tectonic plates, creating and reshaping fault zones, the Martian crust acts like a single, slowly cooling, contracting shell. The findings mean Valles Marineris joins a growing list of regions on Mars known to have active faults, including the Cerebus Fossi fissures and the southern Elysium Planitia plain. This is space time. Still to come, our incredibly shrinking moons. and new clues as to when Van Gogh's famous painting The Starry Night was painted. All that and more still to come on Space Time. A new study of young tectonic landforms on the lunar surface suggests the moon shrunk by at least 90 metres over the past 400 to 800 million years. The findings, reported in the Planetary Science Journal, offers the most detailed estimate yet of how much the moon has contracted as its interior gradually cools over time. The authors identified over 10,000 young fault lines distributed across the lunar surface. The study's lead author, Thomas Waters, from the Smithsonian National Air and Space Museum, used observations from NASA's Lunar Reconnaissance Orbiter to map thousands of contracted landforms known as lobate scarps and small mare ridges across both the lunar highlands and the maria, those vast, dark plains visible on the moon's surface. Waters says if the rate of radius decreases remain constant, it suggests the moon's been shrinking by about 6 to 11 centimeters every million years. That's far less than the average rate at which the Earth's tectonic plates move, which is about one and a half centimetres annually. That's driven by heat loss from the Earth's interior. The Earth's plate boundaries localise about 90% of the planet's tectonic and seismic activity. But the Moon is just a single plate body with faults that express contraction. Unlike the Earth, with its mosaic of more than 15 lithospheric plates, the Moon's single plate acts like a giant unbroken shell. So, as the lunar interior cools and contracts... Faults are not concentrated along the plate boundaries, but are widely distributed across the lunar surface. This means that moonquakes from slip events on existing faults, or from the formation of new faults, can occur anywhere on the moon. The new study also reveals that some areas have more faults than others, and that the thickest lunar crust appears to have the fewest faults, suggesting these areas must be the most stable. The paper suggests the widespread faulting on the moon didn't occur early in lunar history because a heavily fractured thick porous crust insulated the interior, inhibiting cooling and contraction until relatively recently. The Lunar Reconnaissance Orbit has been circling the moon for the past 17 years, and in that time it's returned millions of images of the lunar surface. this report from NASA TV. A newly published study using images from NASA's Lunar Reconnaissance Orbiter revealed tantalizing hints that the Moon has slightly shrunk in the recent geologic past, and in fact may still be actively shrinking today. The research, led by Dr. Tom Waters from the Smithsonian National Air and Space Museum, involved searching thousands of lunar images for specific fault structures called lobate scarps. We know the moon is shrinking by looking at the lobate scarps in detail. They actually reflect the crustal materials of the moon being pushed together, breaking, and being thrust over one another. So that indicates that something has been causing the moon to actually contract or shrink. Finding that the lobate scarps are globally distributed indicates that contraction of a lunar surface is happening on a global scale, and this is critical knowledge to understand the geologic history of the moon. The next steps in this research will be to more accurately assess the age of these scarps to help determine how geologically active the moon might still be today. What's exciting about these findings for me is that the moon is not a dead body. It's not an object where everything that happened on the moon happened billions of years ago. These scarps could be. Younger than a billion years, they could be, in fact, as young as a couple of hundred million years old, or they could be even younger than that. And that means, in geologic terms, the moon is active. And in that report from NASA TV, we heard from Thomas Waters from the Smithsonian National Air and Space Museum. This is space time. Still to come, new clues as to when Van Gogh painted the famous The Starry Night painting. And later in the science report, discovery of a fossil of a Chinese Jurassic-era creature with features very similar to the Australian platypus. All that and more still to come on Space Time. A new study suggests that the position of the stars, planets and the moon in Vincent van Gogh's painting The Starry Night may have been painted before dawn on the morning of the 22nd of July, 1889. The research, published in the journal Scientific Reports, combined astronomical simulations and measurements of star positions, historical weather records, and Van Gogh's letters about the weather at the time in order to determine the likely date that the painting was created. The authors say their evidence points to a day in July rather than the previously suggested June date, but they caution they can't definitively establish a single completion date and that observations from several nights may have been combined in the painting. The oil on canvas by the Dutch post-impressionist depicts a view from the east-facing window of his asylum room at Saint-Rémy-de-Provence and was crafted a year after he painted Starry Night Over the Rhone and Café Terrace at Night, which was originally entitled Coffee House in the Evening. This is Space Time. Space Time. And time now 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 of the dangers of vaping for your heart. The findings reported in the Journal of the American Medical Association show that using nicotine vapes was linked to reduced vascular function. That's where your arteries, veins or small capillaries are stiff, narrowed, inflamed or unable to properly relax and open up. and that affects cardiorespiratory fitness, the ability of your heart, lungs and blood vessels to supply oxygen to your body during exercise. The authors say these findings are similar to those from people who've smoked cigarettes, and far worse than for non-smokers. Paleontologists in China have discovered a fossil of a Jurassic-era creature with features very similar to the Australian platypus. A report in the journal Nature claims that a is a rare opportunity to better understand how mammals learn to suckle milk. The authors say the fossil comes from a newly described species called Megacorda, with teeth, a wide flat tail, and short legs but long feet, which indicates that it's a predator that lived both in and out of the water. And the fossil contains a rare find, a well-preserved throat, which showed the 160-million-year-old creature had the ability to suckle milk and swallow. Because throats are rarely preserved this well, the discovery helps scientists better understand how long fossils have been able to eat in the way they do now. Scientists have developed a fast, low-cost method of manufacturing wire-grid polarizers for terahertz technologies using laser-cut metal foil. A report in the journal Optics and Laser Technology claims the technique can produce polarizers in seconds without expensive clean rooms or specialized fabrication. The technology could potentially enable cheaper high-performing components for terahertz imaging, spectroscopy, and for communication systems. A new study shows that people who feel anxious about relationships are more likely to have more problematic issues with social media use. The findings, reported in the journal PLOS One, are based on a study of more than 500 American adults. The authors found that people who wanted closeness but were afraid of getting hurt reported the most compulsive use of social media, while people who felt secure in their relationships reported the least amount of use. Those who were sensitive to criticism and needed approval from others also tended to report more problems. The authors say that while the study can't show whether relationship insecurities cause problematic habits, its findings suggest that people's emotional needs may help explain why some struggle to manage their social media use. A serious vulnerability has been found in a computer language known as PHP, which has led to websites around the world being taken down as a precaution. The program is used by almost 70% of websites, including WordPress, Wikipedia, Slack and much of Facebook. The vulnerability has sparked warnings that organized criminals could exploit the floor, carrying out cyber attacks. With the details, we're joined by technology editor Alex Saharov-Royd from TechAdvice.life. PHP stands for the Hypertext Pre-Processor, and the first letter P stands for the acronym itself. It's a bit like ATM machine or PIN number, where part of the acronym is actually then spelled out, which is a bit weird, but that's just the way that it is. And it is a programming language that runs behind websites. It's a database that contains all the information. There's a SQL server there and PHP is a programming language. And this was created back in 1994. And thanks to AI, we now have the ability for AI systems to look for vulnerabilities in code that may have been there for days, weeks, months, years, even decades. And because most websites actually do have this PHP database system running in the background, when there's a vulnerability that allows people to, you know, hackers to break into systems, they can do that and then not have anything stopping them from rifling through the information contained in the website. And we even had the situation where the Australian Cyber Security Centre, which gave this warning, I mean, its website, part of the ASD, which is the Australian Signals Directorate, there's a website called cyber.gov.au. They had to take the website down for 24 hours until the patches were made available because there was a chance that the government's own cybersecurity website could have been hacked. So the only thing they could do was take it down. Now, I went to the hosting company that I use and I wanted to speak to somebody in the support division. But even before I was able to do that, the system was telling me, look, we have seen that these vulnerabilities exist and we are applying the patches on your behalf. So there's nothing that you as an individual need to do. And now... Not every hosting company does that. Companies host their own websites and some companies are with hosting companies that don't have this particular kind of rush to protect their users. That's Alex Zaharov-Royd from techadvice.life. 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. Just go to spacetimewithstuartgary.com for full details. You've been listening to Spacetime with Stuart Gary. This has been another quality podcast production from Bytes.com.
