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

0:00 Speaker 1: Hello, and welcome to Astronomy Daily, your daily dose of

0:04 Speaker 1: what's happening in the cosmos. I'm Avery and I'm Anna.

0:08 Speaker 2: It is Wednesday, the eleventh of March twenty twenty six,

0:11 Speaker 2: and this is Season five, Episode sixty, which means sixty

0:15 Speaker 2: episodes of bringing you the Universe one day at a time.

0:19 Speaker 1: Sixty episodes this year. That's a lot of space news,

0:23 Speaker 1: and today's lineup is not letting up. We've got neutron

0:27 Speaker 1: stars colliding in places nobody expected, a potential cosmic snowball

0:32 Speaker 1: fight between asteroids, and a giant invisible sheet of dark

0:36 Speaker 1: matter that explains one of Astronomy's longest running mysteries.

0:40 Speaker 2: Plus the latest on Artemis two starship's next giant leap,

0:45 Speaker 2: and a rocket that can't seem to get off the ground,

0:48 Speaker 2: but not for lack of trying.

0:50 Speaker 1: Day with us. It's a big one.

0:52 Speaker 2: We start today with one of the most remarkable astronomy

0:55 Speaker 2: announcements in recent memory, and it literally involves gold.

1:00 Speaker 1: That's right. NASA has just published a major new finding.

1:04 Speaker 1: A fleet of its space telescopes has likely detected a

1:07 Speaker 1: collision between two neutron stars and the location where this

1:11 Speaker 1: happened has stunned researchers, though.

1:13 Speaker 2: Let's back up for listeners who might not be familiar

1:16 Speaker 2: with neutron stars. These are the remnants left behind when

1:19 Speaker 2: a massive star burns out, collapses on itself, and explodes

1:24 Speaker 2: in a supernova. What's left is this tiny, unbelievably dense ball,

1:29 Speaker 2: about the width of a city, but containing more mass

1:32 Speaker 2: than our entire sun.

1:34 Speaker 1: And when two of those collide, which is called a

1:36 Speaker 1: neutron star merger, it produces one of the most violent

1:40 Speaker 1: events in the universe. We're talking gamma ray bursts, gravitational

1:45 Speaker 1: waves rippling through spacetime, and something called a killinova explosion.

1:50 Speaker 1: That's the process that forges heavy elements things like gold, silver,

1:54 Speaker 1: and platinum, through a chain of nuclear reactions that can't

1:57 Speaker 1: happen anywhere else in the cosmos.

2:00 Speaker 2: We've seen these mergers before, but always inside large or

2:04 Speaker 2: moderately sized galaxies. That's what makes this discovery so jaw dropping.

2:09 Speaker 2: This one was found inside a tiny, faint galaxy, barely there,

2:14 Speaker 2: tucked inside a vast stream of gas four point seven

2:17 Speaker 2: billion light years away, a location nobody thought to look.

2:21 Speaker 1: The lead researcher, Simone Dichiara of Penn State University called

2:26 Speaker 1: it quote game changing, saying it may unlock not one,

2:29 Speaker 1: but two important questions in astrophysics. One is why gamma

2:34 Speaker 1: ray bursts sometimes appear in the middle of nowhere, not

2:37 Speaker 1: near any galaxy at all, And the other is how

2:40 Speaker 1: precious metals ended up in stars at the very outer

2:43 Speaker 1: fringes of galaxies.

2:45 Speaker 2: The answer, it seems, is that small, wandering galaxies like

2:48 Speaker 2: this one can form from the debris of larger galactic

2:52 Speaker 2: collisions and eventually produce their own neutron stars, which then merge.

2:57 Speaker 2: Co author Eleanora Troja of the University of Rome put

3:00 Speaker 2: it beautifully. We found a collision within a collision. The

3:04 Speaker 2: galaxy collision triggered star formation, which over hundreds of millions

3:09 Speaker 2: of years, led to the neutron star merger we just detected.

3:13 Speaker 1: Four space telescopes were involved in making this discovery, Chandra Fermi,

3:18 Speaker 1: the Neil Garrels, Swift Observatory, and Hubble. It took all

3:22 Speaker 1: of them working together to pinpoint the location and confirm

3:25 Speaker 1: what they were seeing. The paper has just been published

3:28 Speaker 1: in the Astrophysical journal Letters.

3:30 Speaker 2: Though the gold in your jewelry it may have come

3:33 Speaker 2: from a tiny galaxy in a gas stream after a

3:37 Speaker 2: chain of collisions spanning billions of years. I think that's

3:41 Speaker 2: one of the most extraordinary facts in all of science.

3:44 Speaker 1: Puts a new spin on where did this come from?

3:47 Speaker 1: Doesn't it okay? Coming up next an update on Artemis two,

3:51 Speaker 1: the mission that is almost almost almost ready to fly.

3:56 Speaker 2: So Artemis two, if you've been following the show, you

3:59 Speaker 2: know that this mission has had quite a journey just

4:02 Speaker 2: to get to the launch pad, and today there's a

4:04 Speaker 2: significant development.

4:06 Speaker 1: NASA has announced it will hold a flight readiness press

4:09 Speaker 1: conference tomorrow Thursday, March twelfth, at Kennedy Space Center in Florida.

4:14 Speaker 1: This is the formal milestone where engineers and mission leaders

4:17 Speaker 1: assess whether everything is technically ready to fly. It's a

4:21 Speaker 1: big deal just to.

4:23 Speaker 2: Bring everyone up to speed. Artemis two is the first

4:26 Speaker 2: crude mission of NASA's Space Launch System. Four astronauts Reid Wiseman,

4:31 Speaker 2: Victor Glover, Christina Coach, and Canadian Space Agency astronaut Jeremy

4:36 Speaker 2: Hansen will fly around the Moon and back on a

4:39 Speaker 2: ten day journey. It will be the first time humans

4:42 Speaker 2: have reached the Moon's vicinity since Apollos seventeen in nineteen

4:46 Speaker 2: seventy two.

4:48 Speaker 1: The mission has had a series of delays. Back in February,

4:51 Speaker 1: a hydrogen leak was found during a wet dress rehearsal.

4:55 Speaker 1: Then after a second successful rehearsal, a helium flow issue

4:59 Speaker 1: was discovered in the upper stage, which caused the rocket

5:01 Speaker 1: to be rolled back into the Vehicle assembly building for repairs.

5:05 Speaker 1: That pushed to launch out of March entirely.

5:08 Speaker 2: The current target is April first at the earliest, with

5:12 Speaker 2: rollout back to Launch Complex thirty nine B expected around

5:15 Speaker 2: March nineteenth. Bassa has also announced a major restructuring of

5:20 Speaker 2: the broader Artemis program, adding a new mission, increasing launch

5:24 Speaker 2: cadence and targeting annual lunar missions with the first crude

5:28 Speaker 2: landing in twenty twenty eight.

5:30 Speaker 1: So tomorrow's press conference will be really telling. We'll know

5:33 Speaker 1: more about the state of the rocket, the official launch

5:36 Speaker 1: readiness verdict, and possibly more details on that April launch window.

5:40 Speaker 1: Will of course have full coverage as the story develops.

5:43 Speaker 2: Fingers crossed for April. The crew has been in training

5:46 Speaker 2: for years. They deserve their moonshot.

5:49 Speaker 1: They absolutely do. Let's take a short break and come

5:52 Speaker 1: back with a story about a rocket trying very hard

5:55 Speaker 1: to leave the ground and a cosmic snowball fight nobody

5:58 Speaker 1: saw coming.

6:00 Speaker 2: All right. Firefly Aerospace, the small launch company, has been

6:04 Speaker 2: trying to get its Alpha rocket back into the sky

6:06 Speaker 2: for weeks, and once again the mission has been delayed.

6:10 Speaker 1: The mission is called Stairway to seven, which refers to

6:13 Speaker 1: this being Alpha's seventh flight overall. It was originally scheduled

6:17 Speaker 1: for March first, but high wind scrubbed that attempt. Then

6:21 Speaker 1: on March ninth, a censor reading outside the expected range

6:25 Speaker 1: caused another standown, and last night, March tenth, a third

6:29 Speaker 1: attempt was scrubbed during fluid loading after off normal readings

6:33 Speaker 1: were detected.

6:34 Speaker 2: No new launch date has been announced yet. Firefly says

6:37 Speaker 2: they're reviewing the data and will confirm a new window

6:40 Speaker 2: once the investigation is complete.

6:42 Speaker 1: Now it's worth understanding why this mission matters. Alpha has

6:46 Speaker 1: had a rough run. The sixth flight, called Message In

6:49 Speaker 1: a Booster, ended when the first stage broke apart just

6:53 Speaker 1: after separation, destroying the payload. Then in September, a booster

6:57 Speaker 1: intended for flight seven exploded during ground testing. The company

7:02 Speaker 1: has been working for nearly ten months to get back

7:04 Speaker 1: to the launch.

7:05 Speaker 2: Pad and Stairway to seven is carrying significant symbolic weight.

7:10 Speaker 2: It's the last flight of the Alpha Block one configuration.

7:13 Speaker 2: After this, Firefly moves to the upgraded Block two, which

7:17 Speaker 2: is seven feet taller, uses new in house avionics and batteries,

7:21 Speaker 2: improved thermal protection, and stronger carbon composite structures. Block two

7:26 Speaker 2: systems are actually flying on this mission in shadow mode,

7:30 Speaker 2: testing quietly in the background without controlling the flight.

7:34 Speaker 1: Firefly also had a big success recently. Their Blue Ghost

7:37 Speaker 1: lander completed the first ever private lunar surface mission last March.

7:42 Speaker 1: So the company's in an interesting position. Proven on the Moon,

7:45 Speaker 1: but still working through reliability challenges with their launch vehicle.

7:49 Speaker 2: Small launch is hard. We're reading for them. When Stairway

7:53 Speaker 2: to seven eventually gets off the ground, we'll give it

7:56 Speaker 2: the full coverage it deserves.

7:58 Speaker 1: Absolutely now, Cosmic snowballs, you heard that right.

8:02 Speaker 2: So you might remember NASA's Dart mission, the spacecraft that

8:08 Speaker 2: intentionally smashed into an asteroid in twenty twenty two to

8:12 Speaker 2: test whether we could deflect one that might threaten Earth.

8:16 Speaker 2: It worked beautifully, as we reported last week.

8:19 Speaker 1: But scientists are still finding new surprises in the data

8:23 Speaker 1: from that mission and this one. Is genuinely delightful. A

8:27 Speaker 1: team at the University of Maryland has just published a

8:30 Speaker 1: study revealing that asteroids can throw slow moving chunks of

8:33 Speaker 1: debris at each other in what they're calling and I

8:36 Speaker 1: love this a cosmic snowball fight.

8:39 Speaker 2: So here's what happened. The Dart spacecraft hid an asteroid

8:44 Speaker 2: moon called Dimorphous, which orbits a larger asteroid called Ditamos.

8:49 Speaker 2: In the images captured by the spacecraft, in the moments

8:52 Speaker 2: before impact, researchers noticed something odd, faint, fan shaped streaks

8:58 Speaker 2: across Dimorphos.

9:00 Speaker 1: Lead author Jessica Sunshine said, and this quote is great.

9:04 Speaker 1: At first we thought something was wrong with the camera,

9:07 Speaker 1: and then we thought it could have been something wrong

9:10 Speaker 1: with our image processing. But after months of paint staking work,

9:14 Speaker 1: stripping away boulder shadows and correcting for lighting, the streaks

9:18 Speaker 1: became clear, not fainter, they were real.

9:21 Speaker 2: What the team discovered is that these streaks are the

9:24 Speaker 2: imprint of debris thrown off Dinamos by something called the

9:29 Speaker 2: Yorp effect, where sunlight gradually spins a small asteroid faster

9:34 Speaker 2: and faster until loose material flies off the surface. Some

9:39 Speaker 2: of that material then drifts across to dimorphous and lands

9:43 Speaker 2: on it, leaving these distinctive ray patterns.

9:46 Speaker 1: And the speed of this material transfer just thirty point

9:50 Speaker 1: seven centimeters per second. That's slower than a leisurely human walk.

9:55 Speaker 1: These are the gentlest cosmic snowballs imaginable.

9:59 Speaker 2: It's the the first direct visual proof that material can

10:03 Speaker 2: travel naturally from one asteroid to another, and it has

10:07 Speaker 2: real implications for planetary defense. If binary asteroids are constantly

10:12 Speaker 2: exchanging material and reshaping each other, scientists need to account

10:17 Speaker 2: for that when modeling how to deflect one.

10:20 Speaker 1: There's also a follow up mission on the way. Eesa's

10:24 Speaker 1: Harris spacecraft is set to arrive at the Denamo system

10:27 Speaker 1: in December this year and maybe able to see whether

10:30 Speaker 1: those fan shaped streaks survive the dart impact or whether

10:34 Speaker 1: new ones have formed. More cosmic forensics to come.

10:38 Speaker 2: A snowball fight spanning millions of years between two rocks

10:42 Speaker 2: in the dark of space.

10:44 Speaker 1: I love this job. After this break, Starship is getting

10:47 Speaker 1: even bigger, and we go looking for the giant, invisible

10:51 Speaker 1: sheet of matter that may be holding our cosmic neighborhood together.

10:55 Speaker 2: Basex's Starship program is marching on, and the next milestone

10:59 Speaker 2: is approaching.

11:00 Speaker 1: Fast Elon Musk announced this week that SpaceX is approximately

11:05 Speaker 1: four weeks away from launching Starship Flight twelve, which will

11:09 Speaker 1: be the first flight of the upgraded Starship V three configuration,

11:13 Speaker 1: the most powerful version of the vehicle yet.

11:16 Speaker 2: FACEX engineers have been working through propellant system tests on

11:21 Speaker 2: Ship thirty nine, that's the newest vehicle, and some of

11:24 Speaker 2: those tests produced some spectacular imagery this week. The team

11:28 Speaker 2: is moving methodically through pre flight preparations at Starbase in Texas.

11:34 Speaker 1: Now, Starship V three is described as a significant step up.

11:38 Speaker 1: The rocket already holds the title of the most powerful

11:41 Speaker 1: launch vehicle ever built, and the V three configuration pushes

11:45 Speaker 1: that capability further, which is critical for the missions ahead,

11:49 Speaker 1: including NASA's Artemis lunar landings, where a Starship variant will

11:53 Speaker 1: be used as the human landing system.

11:56 Speaker 2: Light twelve won't carry the Artemis lander, of course, that's

12:00 Speaker 2: further down the road, but each integrated flight test builds

12:04 Speaker 2: toward that goal, demonstrating reliability, reusability, and the ability to

12:09 Speaker 2: handle increasingly complex mission profiles.

12:12 Speaker 1: So if all goes to plan, we're looking at mid

12:15 Speaker 1: to late April for Flight twelve. Liftoff. We'll keep a

12:18 Speaker 1: close eye on that timeline and give you the full

12:20 Speaker 1: launch preview when the date firms up.

12:23 Speaker 2: The pace of development at SpaceX is extraordinary. And now,

12:27 Speaker 2: to cap off today's show, a cosmic mystery that's been

12:31 Speaker 2: puzzling astronomers for decades, and it might finally be solved.

12:35 Speaker 1: Here's a question that sounds simple. If our galaxy is

12:38 Speaker 1: so massive and has such a powerful gravitational pull, why

12:42 Speaker 1: are most nearby galaxies flying away from us rather than

12:46 Speaker 1: being pulled inward.

12:47 Speaker 2: It's something that's bugged astronomers for decades. Edwin Hubble established

12:52 Speaker 2: almost a century ago that the universe is expanding. Galaxies

12:56 Speaker 2: are receding from each other as space itself stretches. But

13:00 Speaker 2: the galaxies right next to us, just outside our local group,

13:04 Speaker 2: seemed to be moving away faster than they should. Even

13:07 Speaker 2: accounting for that expansion, something wasn't adding up.

13:11 Speaker 1: A team from the University of Groningen in the Netherlands,

13:14 Speaker 1: working with collaborators in Germany, France, and Sweden, may have

13:18 Speaker 1: cracked it. They built what they call a virtual twin

13:21 Speaker 1: of our cosmic neighborhood, running advanced simulations starting from the

13:25 Speaker 1: early universe based on conditions measured in the cosmic microwave

13:29 Speaker 1: background all the way through to today.

13:32 Speaker 2: What they found is remarkable. The matter surrounding the local group,

13:36 Speaker 2: our cluster of galaxies, including the Milky Way and Andromeda,

13:40 Speaker 2: isn't spread out evenly in a sphere the way scientists

13:43 Speaker 2: had assumed. Instead, it's organized into a vast flat sheet

13:48 Speaker 2: of matter stretching tens of millions of light years across.

13:52 Speaker 2: Above and below this sheet lie enormous empty voids where

13:56 Speaker 2: there's essentially nothing.

13:58 Speaker 1: And when they included this flat structure in their models,

14:00 Speaker 1: the motion of thirty one nearby galaxies matched almost perfectly

14:04 Speaker 1: with what astronomers actually observe. The sheet's mass, which is

14:08 Speaker 1: mostly invisible dark matter, counterbalances the local group's gravitational poll,

14:13 Speaker 1: so galaxies within the plane drift outward in an orderly

14:17 Speaker 1: way while nothing falls in from the voids above and below.

14:21 Speaker 2: Bead researcher ewad Wemp said this is the first detailed

14:25 Speaker 2: attempt to map the distribution and motion of dark matter

14:28 Speaker 2: in the region around the Milky Way and Andromeda, and

14:32 Speaker 2: co researcher Professor Amina Helmy, who has worked on this

14:35 Speaker 2: problem for years, said She was thrilled to see that

14:38 Speaker 2: galaxy motions alone could reveal the mass distribution shaping our

14:43 Speaker 2: local cosmic neighborhood.

14:45 Speaker 1: What I find incredible about this is that we're essentially

14:47 Speaker 1: embedded in a cosmic structure we couldn't see. The Milky

14:51 Speaker 1: Way isn't floating freely in space. It's sitting on a

14:55 Speaker 1: vast flat sheet of dark matter, surrounded by emptiness on

14:58 Speaker 1: either side in equilibri.

15:00 Speaker 2: It's like being a grain of sand on a giant

15:03 Speaker 2: cosmic beach and only just realizing the beach exists. The

15:07 Speaker 2: paper is published in Nature Astronomy, and we expect it

15:11 Speaker 2: to generate significant follow up work as astronomers look to

15:15 Speaker 2: confirm the structure with additional observations.

15:18 Speaker 1: Amazing. What a lineup for episode sixty.

15:21 Speaker 2: And that's our show for today. Let's do a quick

15:23 Speaker 2: recap of what we covered.

15:25 Speaker 1: Asad discovered a neutron star collision in a tiny galaxy

15:28 Speaker 1: buried in a gas stream, the first time this has

15:31 Speaker 1: been seen in such an unlikely location.

15:34 Speaker 2: The Artemis two flight readiness review is happening tomorrow. We're

15:38 Speaker 2: watching closely ahead of the April launch window.

15:41 Speaker 1: Firefly Alphas Stairway to seven mission is still on hold

15:45 Speaker 1: after a third scrub. A new launch date will be

15:47 Speaker 1: announced after engineering review.

15:50 Speaker 2: DART mission data revealed the first ever direct visual proof

15:54 Speaker 2: of material transfer between two asteroids, the most gentle cosmic

15:59 Speaker 2: snowball fight us you can imagine.

16:01 Speaker 1: SpaceX is about four weeks from launching Starship Flight twelve,

16:05 Speaker 1: the first flight of the more powerful V three configuration.

16:08 Speaker 2: And astronomers have discovered a vast flat sheet of dark

16:12 Speaker 2: matter surrounding our local group, finally explaining why nearby galaxies

16:17 Speaker 2: behave the way they do.

16:19 Speaker 1: As always, you can find us at astronomydaily dot io

16:22 Speaker 1: and on all major podcast platforms. Joe Notes, episode archive

16:26 Speaker 1: and more are all there for you.

16:28 Speaker 2: If you're enjoying the show, please subscribe, leave us a review,

16:32 Speaker 2: and share us with a fellow space enthusiast. It means

16:36 Speaker 2: the world to us and genuinely helps the show grow.

16:39 Speaker 1: We'll be back tomorrow with more from the universe. Until then,

16:43 Speaker 1: keep looking up clear skies, everyone. Sunday Stars Stars story

17:05 Speaker 1: is ConTroll