S03E193: Voyager's Vanishing Act, Tiangong's Triumph, and Miranda's Icy Secret

Welcome to Astronomy Daily, your source for the latest space and astronomy news. I'm your host Anna, and today we've got an exciting lineup in store for you. We'll be diving into some fascinating stories, from Voyager 1's latest communication challenges at the edge of our solar system to intriguing new discoveries about potential ocean worlds. From the furthest reaches of human exploration to surprising findings closer to home, we've got a packed show ahead that you won't want to miss. Let's dive into our first story of the day, which takes us to the very edge of human exploration. NASA's legendary Voyager 1 spacecraft, now an astounding 15 billion miles from Earth, recently gave its team quite a scare when it temporarily fell silent. After decades of faithful service, the spacecraft's communications went dark, triggering an intensive effort to reestablish contact.

The drama began on October 16th when the flight team sent what should have been a routine command to turn on one of the spacecraft's heaters. Despite having sufficient power for this operation, something unexpected happened - the spacecraft's fault protection system was triggered, leading to a series of communication challenges. The situation became even more complex when Voyager switched from its usual X-band radio transmitter to a backup S-band system - something it hadn't used since 1981. This was particularly concerning because, at such an enormous distance, the weaker S-band signal might not have been detectable from Earth at all.

Imagine trying to troubleshoot a computer problem, but instead of being able to walk over and check what's wrong, your commands take 23 hours just to reach the device, and another 23 hours to get a response back. That's exactly what NASA's engineers faced as they worked to solve this puzzle across the vast expanse of space. Thankfully, through some impressive detective work and engineering expertise, NASA successfully reestablished contact with Voyager 1 on October 24th. The spacecraft appears to be stable, though engineers are still working to understand exactly what triggered these issues in the first place. This incident serves as a reminder of both the remarkable longevity of the Voyager mission - now over 47 years old - and the increasing challenges of maintaining such aging spacecraft in the uncharted territory of interstellar space. It's truly remarkable that we can still communicate with this pioneer of space exploration, even as it ventures further into the unknown than any human-made object in history.

In a significant step for China's space program, a new crew of three astronauts successfully launched to the Tiangong space station in the early hours of Wednesday morning. The Shenzhou-19 mission lifted off at 4:27 am local time from the Jiuquan Satellite Launch Center in northwest China, marking another milestone in the nation's ambitious space exploration journey. Among the crew is 34-year-old Wang Haoze, who joins the elite ranks as China's third woman to participate in a crewed space mission. What makes Wang particularly noteworthy is her role as the country's only female spaceflight engineer, bringing unique technical expertise to the mission. The crew is led by veteran astronaut Cai Xuzhe, a 48-year-old former air force pilot who brings valuable experience from his previous stint aboard Tiangong during the Shenzhou-14 mission in 2022. Rounding out the team is 34-year-old Song Lingdong, completing this carefully selected trio of space explorers. During their approximately six-month stay aboard Tiangong, the crew will conduct various scientific experiments, with a particularly interesting focus on testing special "bricks" made from materials that simulate lunar soil. This research directly ties into China's broader ambitions of establishing a human presence on the Moon by 2030. These lunar soil experiments are especially significant as scientists hope to eventually use actual Moon materials for constructing their planned lunar base, potentially revolutionizing how we approach off-world construction. This mission represents more than just another crew rotation - it's a crucial stepping stone in China's expanding space program. The country has made remarkable progress in recent years, including successfully landing rovers on both Mars and the Moon, and establishing Tiangong as their crown jewel in low Earth orbit. The new crew is scheduled to return to Earth in late April or early May of next year, continuing the steady rhythm of operations that has characterized China's presence in space. Their mission demonstrates China's growing capabilities in space exploration and their commitment to maintaining a continuous human presence in orbit. Let's move further out into Space now, a lot further. Fascinating new research has revealed that Miranda, one of Uranus's smallest major moons, might be hiding something remarkable beneath its bizarre surface - a subsurface ocean. What makes this discovery particularly surprising is Miranda's small size, at just 471 kilometers in diameter. The moon's surface has long puzzled scientists with its unique patchwork of jumbled terrain, including what might be the tallest cliff in our entire solar system - a massive 20-kilometer drop called Verona Rupes. But it's what lies beneath this chaotic surface that's now catching researchers' attention.

Using advanced computer modeling, scientists worked backward from Miranda's current surface features to understand what could have created such a complex landscape. Their findings suggest that beneath the moon's icy crust, which is likely less than 30 kilometers thick, there could be an ocean up to 100 kilometers deep. This hidden ocean probably existed in its fullest form between 100 and 500 million years ago, kept liquid by tidal heating from gravitational interactions with Uranus's other moons. When these moons were in orbital resonance with each other, their gravitational tugs created enough heat to maintain liquid water beneath Miranda's surface.

What's particularly intriguing is that the ocean might still exist today, albeit in a thinner form. Scientists believe if it had completely frozen, we would see evidence of expansion cracks on the surface - features that are notably absent. This discovery puts Miranda in the company of other potential ocean worlds like Saturn's Enceladus and Jupiter's Europa, expanding our understanding of where liquid water might exist in our solar system. It's a reminder that even in the coldest, most distant corners of space, the conditions for potential habitability might be more common than we once thought. The findings are even more remarkable considering they're based on decades-old data from Voyager 2's brief 1986 flyby. It shows how modern analytical techniques can reveal new secrets from limited historical observations, while also highlighting the need for new missions to these distant worlds. Now, let's double back to Mars, where new finding suggest there may have been life there a lot more recently than thought. New research from Harvard's Paleomagnetics Lab has dramatically shifted our understanding of Mars's potentially habitable past. Scientists have discovered that the Red Planet's protective magnetic field may have persisted hundreds of millions of years longer than previously thought, lasting until about 3.9 billion years ago rather than disappearing around 4.1 billion years ago. This protective magnetic field, generated by convection in the planet's iron core much like Earth's field today, would have played a crucial role in defending the Martian surface from harmful cosmic rays. The longer this shield remained active, the more time there would have been for potential life to develop and thrive.

The research team reached this conclusion through innovative analysis of Mars's impact basins. These massive craters have traditionally been thought to show weak magnetic signatures because they formed after Mars's magnetic field had already disappeared. However, the Harvard team proposes a different explanation - these weak signatures could instead be evidence that the craters formed during magnetic pole reversals, similar to the way Earth's magnetic poles occasionally flip.

By studying the famous Allan Hills meteorite using a quantum diamond microscope, the researchers found evidence supporting their theory of a longer-lasting magnetic field. This new timeline suggests Mars remained protected from harmful radiation during a crucial period when we believe the planet still had liquid water on its surface. The implications are profound. If Mars maintained its protective magnetic field for hundreds of millions of years longer than we thought, it means the window for potential life to emerge and evolve was significantly larger. The planet would have remained warmer and wetter for longer, with its atmosphere better protected from being stripped away by solar radiation.

This research challenges our previous assumptions about Mars's early history and opens up new possibilities about how long the Red Planet might have been capable of supporting life. It's another piece in the complex puzzle of Mars's transformation from a potentially habitable world to the cold, dry planet we see today. Now, speaking of life on Mars, how about this for an intriguing idea in the future. Here's how we could one day see trees growing on the red sands of Mars - at least according to fascinating new research that maps out the conditions needed to make it possible. And the findings might surprise you.

Scientists at the Warsaw University of Technology have been crunching the numbers on exactly how much we'd need to alter Mars's atmosphere to support tree growth. They looked at everything from temperature requirements to atmospheric pressure and the length of growing seasons needed. Interestingly, the first Martian forests likely wouldn't take root where you might expect. While on Earth, trees grow best in tropical regions, Mars's unique orbital characteristics mean the planet's southern hemisphere experiences longer, warmer summers. This, combined with the extremely low elevation of the Hellas Basin, makes it the most promising location for the first Martian trees. For trees to survive, Mars would need significantly higher temperatures with much less dramatic day-to-night swings than it experiences now. The growing season would need to last at least 110 Martian days. The researchers mapped out precisely how much carbon dioxide would be needed in the atmosphere to create these conditions through the greenhouse effect.

The whole concept might sound like science fiction, but this research provides concrete numbers and specific locations that could guide future terraforming efforts. While we're still a long way from planting the first Martian forest, understanding exactly what it would take brings us one step closer to potentially transforming the Red Planet into a second home for Earth life. Of course, there are still major hurdles to overcome, including establishing sufficient oxygen levels and protecting any plants from harmful radiation. But having a clearer picture of the temperature and atmospheric requirements gives future Mars colonists a better roadmap for what might be possible.

Well, it seems our hopes for a spectacular Halloween sky show have been dashed. Comet C/2024 S1 ATLAS, which initially showed such promising brightness after its discovery in late September, has met a fiery end in the Sun's scorching embrace. The comet gave us early warning signs that it might not survive its close solar encounter. After an initial bright outburst when it was first spotted, it began to fade considerably in early October. Still, astronomers held out hope that it might join the rare ranks of sungrazers that survive their close solar passages. Unfortunately, when the comet entered the field of view of NASA's SOHO solar observatory yesterday morning, it was already showing signs of breaking apart. As it approached within just 330,600 miles of the Sun's surface, about one and a half times the distance between Earth and the Moon, the comet completely disintegrated. What makes this particularly interesting is that calculations suggest this comet had an orbital period of about 953 years. This means it may have visited the inner solar system before, nearly a millennium ago, only to meet its end on this final journey.

While S1 ATLAS joins the thousands of comets that have perished in similar solar encounters, it's worth noting that some sungrazers do survive. The most famous example is perhaps Comet Lovejoy, which in 2011 survived passing just 87,000 miles from the Sun's surface and went on to provide spectacular views for observers on Earth. These close encounters with the Sun give us valuable insights into both the composition of comets and the extreme conditions near our star. While we may have missed out on a bright Halloween comet this year, the next great comet could appear at any time - that's the unpredictable nature of these cosmic visitors that makes them so fascinating to observe.

And that wraps up our coverage for today. I'm Anna, and thank you for joining me for another episode of Astronomy Daily. If you're hungry for more space content, head over to astronomydaily.io where you can sign up for our free daily newsletter and catch up on all the latest space and astronomy news with our constantly updating newsfeed. While you're there, be sure to check out some amazing deals from our sponsors and browse through our complete archive of past episodes. Don't forget to join our growing community on social media - you can find us as AstroDailyPod on Facebook, X, YouTube, Tumbler and TikTok. Until tomorrow, keep looking up and stay curious about our fascinating cosmos.