Gold From a Galactic Collision — Neutron Star Crash Stuns Astronomers | Astronomy Daily S05E60

Hello, and welcome to Astronomy Daily, your daily dose of what's happening in the cosmos. I'm Avery and I'm Anna. It is Wednesday, the eleventh of March twenty twenty six, and this is Season five, Episode sixty, which means sixty episodes of bringing you the Universe one day at a time. Sixty episodes this year. That's a lot of space news, and today's lineup is not letting up. We've got neutron stars colliding in places nobody expected, a potential cosmic snowball fight between asteroids, and a giant invisible sheet of dark matter that explains one of Astronomy's longest running mysteries. Plus the latest on Artemis two starship's next giant leap, and a rocket that can't seem to get off the ground, but not for lack of trying. Day with us. It's a big one. We start today with one of the most remarkable astronomy announcements in recent memory, and it literally involves gold. That's right. NASA has just published a major new finding. A fleet of its space telescopes has likely detected a collision between two neutron stars and the location where this happened has stunned researchers, though. Let's back up for listeners who might not be familiar with neutron stars. These are the remnants left behind when a massive star burns out, collapses on itself, and explodes in a supernova. What's left is this tiny, unbelievably dense ball, about the width of a city, but containing more mass than our entire sun. And when two of those collide, which is called a neutron star merger, it produces one of the most violent events in the universe. We're talking gamma ray bursts, gravitational waves rippling through spacetime, and something called a killinova explosion. That's the process that forges heavy elements things like gold, silver, and platinum, through a chain of nuclear reactions that can't happen anywhere else in the cosmos. We've seen these mergers before, but always inside large or moderately sized galaxies. That's what makes this discovery so jaw dropping. This one was found inside a tiny, faint galaxy, barely there, tucked inside a vast stream of gas four point seven billion light years away, a location nobody thought to look. The lead researcher, Simone Dichiara of Penn State University called it quote game changing, saying it may unlock not one, but two important questions in astrophysics. One is why gamma ray bursts sometimes appear in the middle of nowhere, not near any galaxy at all, And the other is how precious metals ended up in stars at the very outer fringes of galaxies. The answer, it seems, is that small, wandering galaxies like this one can form from the debris of larger galactic collisions and eventually produce their own neutron stars, which then merge. Co author Eleanora Troja of the University of Rome put it beautifully. We found a collision within a collision. The galaxy collision triggered star formation, which over hundreds of millions of years, led to the neutron star merger we just detected. Four space telescopes were involved in making this discovery, Chandra Fermi, the Neil Garrels, Swift Observatory, and Hubble. It took all of them working together to pinpoint the location and confirm what they were seeing. The paper has just been published in the Astrophysical journal Letters. Though the gold in your jewelry it may have come from a tiny galaxy in a gas stream after a chain of collisions spanning billions of years. I think that's one of the most extraordinary facts in all of science. Puts a new spin on where did this come from? Doesn't it okay? Coming up next an update on Artemis two, the mission that is almost almost almost ready to fly. So Artemis two, if you've been following the show, you know that this mission has had quite a journey just to get to the launch pad, and today there's a significant development. NASA has announced it will hold a flight readiness press conference tomorrow Thursday, March twelfth, at Kennedy Space Center in Florida. This is the formal milestone where engineers and mission leaders assess whether everything is technically ready to fly. It's a big deal just to. Bring everyone up to speed. Artemis two is the first crude mission of NASA's Space Launch System. Four astronauts Reid Wiseman, Victor Glover, Christina Coach, and Canadian Space Agency astronaut Jeremy Hansen will fly around the Moon and back on a ten day journey. It will be the first time humans have reached the Moon's vicinity since Apollos seventeen in nineteen seventy two. The mission has had a series of delays. Back in February, a hydrogen leak was found during a wet dress rehearsal. Then after a second successful rehearsal, a helium flow issue was discovered in the upper stage, which caused the rocket to be rolled back into the Vehicle assembly building for repairs. That pushed to launch out of March entirely. The current target is April first at the earliest, with rollout back to Launch Complex thirty nine B expected around March nineteenth. Bassa has also announced a major restructuring of the broader Artemis program, adding a new mission, increasing launch cadence and targeting annual lunar missions with the first crude landing in twenty twenty eight. So tomorrow's press conference will be really telling. We'll know more about the state of the rocket, the official launch readiness verdict, and possibly more details on that April launch window. Will of course have full coverage as the story develops. Fingers crossed for April. The crew has been in training for years. They deserve their moonshot. They absolutely do. Let's take a short break and come back with a story about a rocket trying very hard to leave the ground and a cosmic snowball fight nobody saw coming. All right. Firefly Aerospace, the small launch company, has been trying to get its Alpha rocket back into the sky for weeks, and once again the mission has been delayed. The mission is called Stairway to seven, which refers to this being Alpha's seventh flight overall. It was originally scheduled for March first, but high wind scrubbed that attempt. Then on March ninth, a censor reading outside the expected range caused another standown, and last night, March tenth, a third attempt was scrubbed during fluid loading after off normal readings were detected. No new launch date has been announced yet. Firefly says they're reviewing the data and will confirm a new window once the investigation is complete. Now it's worth understanding why this mission matters. Alpha has had a rough run. The sixth flight, called Message In a Booster, ended when the first stage broke apart just after separation, destroying the payload. Then in September, a booster intended for flight seven exploded during ground testing. The company has been working for nearly ten months to get back to the launch. Pad and Stairway to seven is carrying significant symbolic weight. It's the last flight of the Alpha Block one configuration. After this, Firefly moves to the upgraded Block two, which is seven feet taller, uses new in house avionics and batteries, improved thermal protection, and stronger carbon composite structures. Block two systems are actually flying on this mission in shadow mode, testing quietly in the background without controlling the flight. Firefly also had a big success recently. Their Blue Ghost lander completed the first ever private lunar surface mission last March. So the company's in an interesting position. Proven on the Moon, but still working through reliability challenges with their launch vehicle. Small launch is hard. We're reading for them. When Stairway to seven eventually gets off the ground, we'll give it the full coverage it deserves. Absolutely now, Cosmic snowballs, you heard that right. So you might remember NASA's Dart mission, the spacecraft that intentionally smashed into an asteroid in twenty twenty two to test whether we could deflect one that might threaten Earth. It worked beautifully, as we reported last week. But scientists are still finding new surprises in the data from that mission and this one. Is genuinely delightful. A team at the University of Maryland has just published a study revealing that asteroids can throw slow moving chunks of debris at each other in what they're calling and I love this a cosmic snowball fight. So here's what happened. The Dart spacecraft hid an asteroid moon called Dimorphous, which orbits a larger asteroid called Ditamos. In the images captured by the spacecraft, in the moments before impact, researchers noticed something odd, faint, fan shaped streaks across Dimorphos. Lead author Jessica Sunshine said, and this quote is great. At first we thought something was wrong with the camera, and then we thought it could have been something wrong with our image processing. But after months of paint staking work, stripping away boulder shadows and correcting for lighting, the streaks became clear, not fainter, they were real. What the team discovered is that these streaks are the imprint of debris thrown off Dinamos by something called the Yorp effect, where sunlight gradually spins a small asteroid faster and faster until loose material flies off the surface. Some of that material then drifts across to dimorphous and lands on it, leaving these distinctive ray patterns. And the speed of this material transfer just thirty point seven centimeters per second. That's slower than a leisurely human walk. These are the gentlest cosmic snowballs imaginable. It's the the first direct visual proof that material can travel naturally from one asteroid to another, and it has real implications for planetary defense. If binary asteroids are constantly exchanging material and reshaping each other, scientists need to account for that when modeling how to deflect one. There's also a follow up mission on the way. Eesa's Harris spacecraft is set to arrive at the Denamo system in December this year and maybe able to see whether those fan shaped streaks survive the dart impact or whether new ones have formed. More cosmic forensics to come. A snowball fight spanning millions of years between two rocks in the dark of space. I love this job. After this break, Starship is getting even bigger, and we go looking for the giant, invisible sheet of matter that may be holding our cosmic neighborhood together. Basex's Starship program is marching on, and the next milestone is approaching. Fast Elon Musk announced this week that SpaceX is approximately four weeks away from launching Starship Flight twelve, which will be the first flight of the upgraded Starship V three configuration, the most powerful version of the vehicle yet. FACEX engineers have been working through propellant system tests on Ship thirty nine, that's the newest vehicle, and some of those tests produced some spectacular imagery this week. The team is moving methodically through pre flight preparations at Starbase in Texas. Now, Starship V three is described as a significant step up. The rocket already holds the title of the most powerful launch vehicle ever built, and the V three configuration pushes that capability further, which is critical for the missions ahead, including NASA's Artemis lunar landings, where a Starship variant will be used as the human landing system. Light twelve won't carry the Artemis lander, of course, that's further down the road, but each integrated flight test builds toward that goal, demonstrating reliability, reusability, and the ability to handle increasingly complex mission profiles. So if all goes to plan, we're looking at mid to late April for Flight twelve. Liftoff. We'll keep a close eye on that timeline and give you the full launch preview when the date firms up. The pace of development at SpaceX is extraordinary. And now, to cap off today's show, a cosmic mystery that's been puzzling astronomers for decades, and it might finally be solved. Here's a question that sounds simple. If our galaxy is so massive and has such a powerful gravitational pull, why are most nearby galaxies flying away from us rather than being pulled inward. It's something that's bugged astronomers for decades. Edwin Hubble established almost a century ago that the universe is expanding. Galaxies are receding from each other as space itself stretches. But the galaxies right next to us, just outside our local group, seemed to be moving away faster than they should. Even accounting for that expansion, something wasn't adding up. A team from the University of Groningen in the Netherlands, working with collaborators in Germany, France, and Sweden, may have cracked it. They built what they call a virtual twin of our cosmic neighborhood, running advanced simulations starting from the early universe based on conditions measured in the cosmic microwave background all the way through to today. What they found is remarkable. The matter surrounding the local group, our cluster of galaxies, including the Milky Way and Andromeda, isn't spread out evenly in a sphere the way scientists had assumed. Instead, it's organized into a vast flat sheet of matter stretching tens of millions of light years across. Above and below this sheet lie enormous empty voids where there's essentially nothing. And when they included this flat structure in their models, the motion of thirty one nearby galaxies matched almost perfectly with what astronomers actually observe. The sheet's mass, which is mostly invisible dark matter, counterbalances the local group's gravitational poll, so galaxies within the plane drift outward in an orderly way while nothing falls in from the voids above and below. Bead researcher ewad Wemp said this is the first detailed attempt to map the distribution and motion of dark matter in the region around the Milky Way and Andromeda, and co researcher Professor Amina Helmy, who has worked on this problem for years, said She was thrilled to see that galaxy motions alone could reveal the mass distribution shaping our local cosmic neighborhood. What I find incredible about this is that we're essentially embedded in a cosmic structure we couldn't see. The Milky Way isn't floating freely in space. It's sitting on a vast flat sheet of dark matter, surrounded by emptiness on either side in equilibri. It's like being a grain of sand on a giant cosmic beach and only just realizing the beach exists. The paper is published in Nature Astronomy, and we expect it to generate significant follow up work as astronomers look to confirm the structure with additional observations. Amazing. What a lineup for episode sixty. And that's our show for today. Let's do a quick recap of what we covered. Asad discovered a neutron star collision in a tiny galaxy buried in a gas stream, the first time this has been seen in such an unlikely location. The Artemis two flight readiness review is happening tomorrow. We're watching closely ahead of the April launch window. Firefly Alphas Stairway to seven mission is still on hold after a third scrub. A new launch date will be announced after engineering review. DART mission data revealed the first ever direct visual proof of material transfer between two asteroids, the most gentle cosmic snowball fight us you can imagine. SpaceX is about four weeks from launching Starship Flight twelve, the first flight of the more powerful V three configuration. And astronomers have discovered a vast flat sheet of dark matter surrounding our local group, finally explaining why nearby galaxies behave the way they do. As always, you can find us at astronomydaily dot io and on all major podcast platforms. Joe Notes, episode archive and more are all there for you. If you're enjoying the show, please subscribe, leave us a review, and share us with a fellow space enthusiast. It means the world to us and genuinely helps the show grow. We'll be back tomorrow with more from the universe. Until then, keep looking up clear skies, everyone. Sunday Stars Stars story is ConTroll