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

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Hello and welcome to Astronomy Daily,


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your daily dose of what's happening in


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the cosmos. I'm Avery.


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>> And I'm Anna. It is Wednesday, the 11th


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of March, 2026, and this is season 5,


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episode 60, which means 60 episodes of


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bringing you the universe, one day at a


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time.


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>> 60 episodes this year. That's a lot of


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space news. And today's lineup is not


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letting up. We've got neutron stars


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colliding in places nobody expected. A


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potential cosmic snowball fight between


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asteroids and a giant invisible sheet of


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dark matter that explains one of


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astronomy's longestr running mysteries.


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>> Plus, the latest on Artemis 2,


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Starship's next giant leap and a rocket


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that can't seem to get off the ground,


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but not for lack of trying.


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>> Stay with us. It's a big one. We start


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today with one of the most remarkable


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astronomy announcements in recent


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memory, and it literally involves gold.


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>> That's right. NASA has just published a


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major new finding. A fleet of its space


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telescopes has likely detected a


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collision between two neutron stars. And


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the location where this happened has


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stunned researchers.


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>> Though, let's back up for listeners who


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might not be familiar with neutron


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stars. These are the remnants left


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behind when a massive star burns out,


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collapses on itself, and explodes in a


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supernova. What's left is this tiny,


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unbelievably dense ball about the width


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of a city, but containing more mass than


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our entire sun.


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>> And when two of those collide, which is


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called a neutron star merger, it


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produces one of the most violent events


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in the universe. We're talking gamma ray


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bursts, gravitational waves rippling


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through spaceime, and something called a


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kilanova explosion. That's the process


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that forges heavy elements, things like


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gold, silver, and platinum through a


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chain of nuclear reactions that can't


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happen anywhere else in the cosmos.


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>> We've seen these mergers before, but


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always inside large or moderately sized


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galaxies. That's what makes this


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discovery so jaw-dropping. This one was


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found inside a tiny faint galaxy, barely


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there, tucked inside a vast stream of


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gas 4.7 billion lighty years away. A


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location nobody thought to look.


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>> The lead researcher, Simone Diara of


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Penn State University called it quote


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gamechanging, saying it may unlock not


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one but two important questions in


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astrophysics. One is why gamma ray


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bursts sometimes appear in the middle of


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nowhere, not near any galaxy at all. And


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the other is how precious metals ended


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up in stars at the very outer fringes of


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galaxies. The answer, it seems, is that


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small wandering galaxies like this one


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can form from the debris of larger


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galactic collisions and eventually


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produce their own neutron stars, which


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then merge. Co-author Eleanor Troya of


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the University of Rome put it


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beautifully. We found a collision within


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a collision. The galaxy collision


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triggered star formation which over


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hundreds of millions of years led to the


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neutron star merger we just detected.


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Four space telescopes were involved in


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making this discovery. Chandra, Fermy,


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the Neil Geral swift observatory and


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Hubble. It took all of them working


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together to pinpoint the location and


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confirm what they were seeing. The paper


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has just been published in the


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astrophysical journal letters. Though


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the gold in your jewelry, it may have


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come from a tiny galaxy in a gas stream


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after a chain of collisions spanning


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billions of years. I think that's one of


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the most extraordinary facts in all of


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science.


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>> Puts a new spin on where did this come


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from, doesn't it? Okay, coming up next,


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an update on Artemis 2. The mission that


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is almost almost ready to fly. So,


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Artemis 2, if you've been following the


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show, you know this mission has had


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quite a journey just to get to the


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launchpad. And today, there's a


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significant development.


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>> NASA has announced it will hold a flight


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readiness press conference tomorrow,


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Thursday, March 12th, at Kennedy Space


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Center in Florida. This is the formal


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milestone where engineers and mission


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leaders assess whether everything is


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technically ready to fly. It's a big


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deal. Just to bring everyone up to


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speed, Artemis 2 is the first crude


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mission of NASA's space launch system.


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Four astronauts, Reed Weisman, Victor


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Glover, Christina Coach, and Canadian


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Space Agency astronaut Jeremy Hansen,


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will fly around the moon and back on a


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10-day journey. It will be the first


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time humans have reached the moon's


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vicinity since Apollo 17 in 1972.


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>> The mission has had a series of delays.


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Back in February, a hydrogen leak was


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found during a wet dress rehearsal.


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Then, after a second successful


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rehearsal, a helium flow issue was


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discovered in the upper stage, which


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caused the rocket to be rolled back into


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the vehicle assembly building for


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repairs. That pushed the launch out of


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March entirely. The current target is


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April 1st at the earliest with roll out


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back to launch complex 39B expected


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around March 19th. BASA has also


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announced a major restructuring of the


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broader Artemis program, adding a new


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mission, increasing launch cadence, and


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targeting annual lunar missions with the


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first crude landing in 2028.


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>> So, tomorrow's press conference will be


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really telling. We'll know more about


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the state of the rocket, the official


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launch readiness verdict, and possibly


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more details on that April launch


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window. We'll of course have full


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coverage as the story develops.


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>> Fingers crossed for April. The crew has


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been in training for years. They deserve


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their moonshot.


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>> They absolutely do. Let's take a short


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break and come back with a story about a


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rocket trying very hard to leave the


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ground and a cosmic snowball fight


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nobody saw coming.


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>> All right, Firefly Aerospace. The small


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launch company has been trying to get


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its Alpha rocket back into the sky for


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weeks and once again the mission has


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been delayed. The mission is called


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Stairway to 7, which refers to this


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being Alpha's seventh flight overall. It


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was originally scheduled for March 1st,


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but high wind scrubbed that attempt.


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Then on March 9th, a sensor reading


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outside the expected range caused


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another standown. And last night, March


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10th, a third attempt was scrubbed


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during fluid loading after off-normal


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readings were detected.


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>> No new launch date has been announced


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yet. Firefly says they're reviewing the


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data and will confirm a new window once


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the investigation is complete.


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>> Now, it's worth understanding why this


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mission matters. Alpha has had a rough


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run. The sixth flight called message in


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a booster ended when the first stage


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broke apart just after separation,


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destroying the payload. Then in


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September, a booster intended for flight


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7 exploded during ground testing. The


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company has been working for nearly 10


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months to get back to the launchpad


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>> and stairway to 7 is carrying


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significant symbolic weight. It's the


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last flight of the alpha block one


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configuration. After this, Firefly moves


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to the upgraded block 2, which is 7 ft


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taller, uses new in-house avionics and


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batteries, improved thermal protection,


00:07:23.280 --> 00:07:25.270
and stronger carbon composite


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structures. Block two systems are


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actually flying on this mission in


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shadow mode, testing quietly in the


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background without controlling the


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flight. Firefly also had a big success


00:07:36.319 --> 00:07:38.309
recently. Their Blue Ghost lander


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completed the first ever private lunar


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surface mission last March. So, the


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company's in an interesting position,


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proven on the moon, but still working


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through reliability challenges with


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their launch vehicle.


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>> Small launch is hard. We're reading for


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them. When Stairway to 7 eventually gets


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off the ground, we'll give it the full


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coverage it deserves.


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>> Absolutely. Now, Cosmic Snowballs, you


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heard that, right?


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>> So, you might remember NASA's Dart


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mission, the spacecraft that


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intentionally smashed into an asteroid


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in 2022 to test whether we could deflect


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one that might threaten Earth. It worked


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beautifully, as we reported last week.


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But scientists are still finding new


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surprises in the data from that mission.


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And this one is genuinely delightful. A


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team at the University of Maryland has


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just published a study revealing that


00:08:31.440 --> 00:08:33.829
asteroids can throw slowmoving chunks of


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debris at each other in what they're


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calling, and I love this, a cosmic


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snowball fight.


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>> So, here's what happened. The Dart


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spacecraft hit an asteroid moon called


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Dimorphice, which orbits a larger


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asteroid called Ditimos. In the images


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captured by the spacecraft in the


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moments before impact, researchers


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noticed something odd. Faint fan-shaped


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streaks across Dorphice. Lead author


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Jessica Sunshine said, and this quote is


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great, "At first, we thought something


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was wrong with the camera, and then we


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thought it could have been something


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wrong with our image processing. But


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after months of painstaking work,


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stripping away boulder shadows and


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correcting for lighting, the streaks


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became clearer, not fainter. They were


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real. What the team discovered is that


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these streaks are the imprint of debris


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thrown off Ditimos by something called


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the Yorp effect, where sunlight


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gradually spins a small asteroid faster


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and faster until loose material flies


00:09:37.760 --> 00:09:40.230
off the surface. Some of that material


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then drifts across to Dorphice and lands


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on it, leaving these distinctive ray


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patterns.


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>> And the speed of this material transfer,


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just 30.7 cm/s.


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That's slower than a leisurely human


00:09:54.959 --> 00:09:57.590
walk. These are the gentlest cosmic


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snowballs imaginable. It's the first


00:10:00.640 --> 00:10:03.350
direct visual proof that material can


00:10:03.360 --> 00:10:05.910
travel naturally from one asteroid to


00:10:05.920 --> 00:10:08.470
another, and it has real implications


00:10:08.480 --> 00:10:11.350
for planetary defense. If binary


00:10:11.360 --> 00:10:13.670
asteroids are constantly exchanging


00:10:13.680 --> 00:10:16.069
material and reshaping each other,


00:10:16.079 --> 00:10:18.470
scientists need to account for that when


00:10:18.480 --> 00:10:20.949
modeling how to deflect one. There's


00:10:20.959 --> 00:10:23.350
also a follow-up mission on the way.


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ESA's Hera spacecraft is set to arrive


00:10:26.160 --> 00:10:28.470
at the Ditimos system in December this


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year and may be able to see whether


00:10:30.800 --> 00:10:32.949
those fan-shaped streaks survive the


00:10:32.959 --> 00:10:35.190
dart impact or whether new ones have


00:10:35.200 --> 00:10:38.389
formed. More cosmic forensics to come.


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>> A snowball fight spanning millions of


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years between two rocks in the dark of


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space. I love this job. After this


00:10:46.399 --> 00:10:48.710
break, Starship is getting even bigger


00:10:48.720 --> 00:10:50.550
and we go looking for the giant


00:10:50.560 --> 00:10:52.550
invisible sheet of matter that may be


00:10:52.560 --> 00:10:54.150
holding our cosmic neighborhood


00:10:54.160 --> 00:10:55.269
together.


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>> SpaceX's Starship program is marching on


00:10:58.480 --> 00:11:00.870
and the next milestone is approaching


00:11:00.880 --> 00:11:03.750
fast. Elon Musk announced this week that


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SpaceX is approximately 4 weeks away


00:11:06.240 --> 00:11:09.110
from launching Starship Flight 12, which


00:11:09.120 --> 00:11:11.190
will be the first flight of the upgraded


00:11:11.200 --> 00:11:14.069
Starship V3 configuration, the most


00:11:14.079 --> 00:11:16.790
powerful version of the vehicle yet.


00:11:16.800 --> 00:11:18.949
SpaceX engineers have been working


00:11:18.959 --> 00:11:21.509
through propellant system tests on ship


00:11:21.519 --> 00:11:24.470
39. That's the newest vehicle, and some


00:11:24.480 --> 00:11:27.110
of those tests produced some spectacular


00:11:27.120 --> 00:11:29.509
imagery this week. The team is moving


00:11:29.519 --> 00:11:31.269
methodically through pre-flight


00:11:31.279 --> 00:11:34.710
preparations at Starbase in Texas. Now,


00:11:34.720 --> 00:11:37.110
Starship V3 is described as a


00:11:37.120 --> 00:11:39.509
significant step up. The rocket already


00:11:39.519 --> 00:11:41.590
holds the title of the most powerful


00:11:41.600 --> 00:11:44.310
launch vehicle ever built, and the V3


00:11:44.320 --> 00:11:46.389
configuration pushes that capability


00:11:46.399 --> 00:11:48.230
further, which is critical for the


00:11:48.240 --> 00:11:50.790
missions ahead, including NASA's Aremis


00:11:50.800 --> 00:11:53.350
lunar landings, where a Starship variant


00:11:53.360 --> 00:11:55.350
will be used as the human landing


00:11:55.360 --> 00:11:58.710
system. Flight 12 won't carry the Aremis


00:11:58.720 --> 00:12:00.790
lander, of course, that's further down


00:12:00.800 --> 00:12:03.190
the road, but each integrated flight


00:12:03.200 --> 00:12:05.350
test builds toward that goal,


00:12:05.360 --> 00:12:08.230
demonstrating reliability, reusability,


00:12:08.240 --> 00:12:10.790
and the ability to handle increasingly


00:12:10.800 --> 00:12:12.870
complex mission profiles.


00:12:12.880 --> 00:12:14.710
>> So, if all goes to plan, we're looking


00:12:14.720 --> 00:12:17.190
at mid to late April for Flight 12


00:12:17.200 --> 00:12:19.269
liftoff. We'll keep a close eye on that


00:12:19.279 --> 00:12:21.030
timeline and give you the full launch


00:12:21.040 --> 00:12:23.590
preview when the date firms up. The pace


00:12:23.600 --> 00:12:25.750
of development at SpaceX is


00:12:25.760 --> 00:12:28.389
extraordinary. And now to cap off


00:12:28.399 --> 00:12:30.949
today's show, a cosmic mystery that's


00:12:30.959 --> 00:12:33.509
been puzzling astronomers for decades,


00:12:33.519 --> 00:12:35.670
and it might finally be solved.


00:12:35.680 --> 00:12:37.750
>> Here's a question that sounds simple. If


00:12:37.760 --> 00:12:40.230
our galaxy is so massive and has such a


00:12:40.240 --> 00:12:42.870
powerful gravitational pole, why are


00:12:42.880 --> 00:12:45.829
most nearby galaxies flying away from us


00:12:45.839 --> 00:12:47.750
rather than being pulled inward?


00:12:47.760 --> 00:12:49.670
>> It's something that's bugged astronomers


00:12:49.680 --> 00:12:52.310
for decades. Edwin Hubble established


00:12:52.320 --> 00:12:54.629
almost a century ago that the universe


00:12:54.639 --> 00:12:57.350
is expanding. Galaxies are receding from


00:12:57.360 --> 00:13:00.069
each other as space itself stretches.


00:13:00.079 --> 00:13:02.790
But the galaxies right next to us, just


00:13:02.800 --> 00:13:05.030
outside our local group, seem to be


00:13:05.040 --> 00:13:07.509
moving away faster than they should,


00:13:07.519 --> 00:13:09.990
even accounting for that expansion.


00:13:10.000 --> 00:13:11.750
Something wasn't adding up.


00:13:11.760 --> 00:13:13.670
>> A team from the University of Groigan in


00:13:13.680 --> 00:13:15.030
the Netherlands working with


00:13:15.040 --> 00:13:17.030
collaborators in Germany, France, and


00:13:17.040 --> 00:13:19.430
Sweden may have cracked it. They built


00:13:19.440 --> 00:13:21.670
what they call a virtual twin of our


00:13:21.680 --> 00:13:23.829
cosmic neighborhood, running advanced


00:13:23.839 --> 00:13:25.750
simulations starting from the early


00:13:25.760 --> 00:13:28.150
universe based on conditions measured in


00:13:28.160 --> 00:13:30.710
the cosmic microwave background all the


00:13:30.720 --> 00:13:33.350
way through to today. What they found is


00:13:33.360 --> 00:13:35.750
remarkable. The matter surrounding the


00:13:35.760 --> 00:13:37.990
local group, our cluster of galaxies,


00:13:38.000 --> 00:13:40.550
including the Milky Way and Andromeda,


00:13:40.560 --> 00:13:42.870
isn't spread out evenly in a sphere the


00:13:42.880 --> 00:13:45.430
way scientists had assumed. Instead,


00:13:45.440 --> 00:13:48.389
it's organized into a vast flat sheet of


00:13:48.399 --> 00:13:50.790
matter stretching tens of millions of


00:13:50.800 --> 00:13:53.430
light years across. Above and below this


00:13:53.440 --> 00:13:56.389
sheet lie enormous empty voids where


00:13:56.399 --> 00:13:58.550
there's essentially nothing. And when


00:13:58.560 --> 00:14:00.230
they included this flat structure in


00:14:00.240 --> 00:14:02.710
their models, the motion of 31 nearby


00:14:02.720 --> 00:14:04.870
galaxies matched almost perfectly with


00:14:04.880 --> 00:14:07.350
what astronomers actually observe. The


00:14:07.360 --> 00:14:09.590
sheets mass, which is mostly invisible


00:14:09.600 --> 00:14:12.069
dark matter, counterbalances the local


00:14:12.079 --> 00:14:14.790
group's gravitational pole. So galaxies


00:14:14.800 --> 00:14:16.949
within the plane drift outward in an


00:14:16.959 --> 00:14:19.509
orderly way while nothing falls in from


00:14:19.519 --> 00:14:21.269
the voids above and below.


00:14:21.279 --> 00:14:23.910
>> Bead researcher Ewad Wemp said this is


00:14:23.920 --> 00:14:26.470
the first detailed attempt to map the


00:14:26.480 --> 00:14:28.870
distribution and motion of dark matter


00:14:28.880 --> 00:14:31.110
in the region around the Milky Way and


00:14:31.120 --> 00:14:33.670
Andromeda. And co-ressearcher, Professor


00:14:33.680 --> 00:14:35.750
Amina Helme, who has worked on this


00:14:35.760 --> 00:14:38.069
problem for years, said she was thrilled


00:14:38.079 --> 00:14:40.629
to see that galaxy motions alone could


00:14:40.639 --> 00:14:43.269
reveal the mass distribution shaping our


00:14:43.279 --> 00:14:45.030
local cosmic neighborhood.


00:14:45.040 --> 00:14:46.790
>> What I find incredible about this is


00:14:46.800 --> 00:14:48.790
that we're essentially embedded in a


00:14:48.800 --> 00:14:51.350
cosmic structure we couldn't see. The


00:14:51.360 --> 00:14:53.350
Milky Way isn't floating freely in


00:14:53.360 --> 00:14:56.069
space. It's sitting on a vast flat sheet


00:14:56.079 --> 00:14:58.310
of dark matter surrounded by emptiness


00:14:58.320 --> 00:15:01.189
on either side in equilibrium. It's like


00:15:01.199 --> 00:15:03.990
being a grain of sand on a giant cosmic


00:15:04.000 --> 00:15:06.629
beach and only just realizing the beach


00:15:06.639 --> 00:15:09.509
exists. The paper is published in Nature


00:15:09.519 --> 00:15:12.069
Astronomy and we expect it to generate


00:15:12.079 --> 00:15:13.910
significant follow-up work as


00:15:13.920 --> 00:15:15.750
astronomers look to confirm the


00:15:15.760 --> 00:15:18.230
structure with additional observations.


00:15:18.240 --> 00:15:21.030
>> Amazing. What a lineup for episode 60.


00:15:21.040 --> 00:15:23.189
>> And that's our show for today. Let's do


00:15:23.199 --> 00:15:25.829
a quick recap of what we covered. NASA


00:15:25.839 --> 00:15:27.910
discovered a neutron star collision in a


00:15:27.920 --> 00:15:30.790
tiny galaxy buried in a gas stream. The


00:15:30.800 --> 00:15:32.790
first time this has been seen in such an


00:15:32.800 --> 00:15:34.310
unlikely location.


00:15:34.320 --> 00:15:37.030
>> The Aremis 2 flight readiness review is


00:15:37.040 --> 00:15:38.870
happening tomorrow. We're watching


00:15:38.880 --> 00:15:40.949
closely ahead of the April launch


00:15:40.959 --> 00:15:41.750
window.


00:15:41.760 --> 00:15:44.389
>> Firefly Alpha's Stairway to 7 mission is


00:15:44.399 --> 00:15:47.189
still on hold after a third scrub. A new


00:15:47.199 --> 00:15:48.710
launch date will be announced after


00:15:48.720 --> 00:15:51.189
engineering review. Dart mission data


00:15:51.199 --> 00:15:53.670
revealed the first ever direct visual


00:15:53.680 --> 00:15:56.310
proof of material transfer between two


00:15:56.320 --> 00:15:59.189
asteroids. The most gentle cosmic


00:15:59.199 --> 00:16:01.269
snowball fight you can imagine.


00:16:01.279 --> 00:16:03.590
>> SpaceX is about 4 weeks from launching


00:16:03.600 --> 00:16:06.150
Starship Flight 12, the first flight of


00:16:06.160 --> 00:16:09.269
the more powerful V3 configuration. and


00:16:09.279 --> 00:16:11.829
astronomers have discovered a vast flat


00:16:11.839 --> 00:16:14.069
sheet of dark matter surrounding our


00:16:14.079 --> 00:16:16.790
local group, finally explaining why


00:16:16.800 --> 00:16:19.590
nearby galaxies behave the way they do.


00:16:19.600 --> 00:16:21.030
>> As always, you can find us at


00:16:21.040 --> 00:16:22.870
astronomyaily.io


00:16:22.880 --> 00:16:25.430
and on all major podcast platforms, show


00:16:25.440 --> 00:16:27.829
notes, episode archive, and more are all


00:16:27.839 --> 00:16:28.710
there for you.


00:16:28.720 --> 00:16:30.710
>> If you're enjoying the show, please


00:16:30.720 --> 00:16:33.110
subscribe, leave us a review, and share


00:16:33.120 --> 00:16:35.910
us with a fellow space enthusiast. It


00:16:35.920 --> 00:16:38.230
means the world to us and genuinely


00:16:38.240 --> 00:16:39.829
helps the show grow.


00:16:39.839 --> 00:16:41.509
>> We'll be back tomorrow with more from


00:16:41.519 --> 00:16:43.749
the universe. Until then, keep looking


00:16:43.759 --> 00:16:44.470
up.


00:16:44.480 --> 00:16:56.870
>> Clear skies, everyone.


00:16:56.880 --> 00:17:00.680
Stories told.