Artemis II Soars Beyond the Moon + Comet MAPS' Dramatic Demise

0:00 Speaker 1: Right now, as you're listening to this, there are four

0:03 Speaker 1: human beings flying around the Moon.

0:06 Speaker 2: For the first time since December nineteen seventy two, fifty

0:11 Speaker 2: three years.

0:12 Speaker 1: Reed Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen are

0:17 Speaker 1: aboard NASA's Ryan spacecraft conducting a six hour lunar flyby today,

0:23 Speaker 1: photographing the far side, breaking the all time human distance

0:27 Speaker 1: record from Earth, and about to witness a solar eclipse

0:32 Speaker 1: from beyond the Moon.

0:34 Speaker 2: We also have the verdict on comet maps, the one

0:37 Speaker 2: we promised you on Saturday, did it survive its plunge

0:40 Speaker 2: into the Sun.

0:41 Speaker 1: Plus a third galaxy with no dark matter, eighty seven

0:46 Speaker 1: hidden stellar streams discovered in our own galaxy, and a

0:50 Speaker 1: new telescope that found eleven thousand asteroids in just six weeks.

0:56 Speaker 1: I'm Avery and I'm Anna. This is Astronomy Daily, Season five,

1:00 Speaker 1: episode eighty two. Let's go.

1:03 Speaker 2: Let's start where we left off on Saturday, flight day

1:06 Speaker 2: four for the Artemis two crew.

1:09 Speaker 1: At the start of the day, Oriyan and her crew

1:11 Speaker 1: were approximately one hundred and sixty nine thousand miles from

1:15 Speaker 1: Earth and one hundred and ten thousand miles from the

1:18 Speaker 1: Moon halfway there and closing fast.

1:22 Speaker 2: The big activity on day four was a manual piloting demonstration.

1:26 Speaker 2: Christina Coke and Jeremy Hansen took turns at the controls

1:30 Speaker 2: testing two different thruster modes to give engineers real deep

1:33 Speaker 2: space handling data on the spacecraft.

1:36 Speaker 1: And this isn't just for show. Commander Wiseman and Victor

1:40 Speaker 1: Glover are scheduled to repeat the same demonstration on day

1:44 Speaker 1: eight so mission controllers can compare how different crew members

1:48 Speaker 1: handle the spacecraft its proper test flight methodology.

1:52 Speaker 2: The crew also spent time reviewing their lunar science target

1:55 Speaker 2: list for today's flyby, about thirty five geological features they've

1:59 Speaker 2: been asked to observe and photograph. Top of that list

2:03 Speaker 2: is the Orientel Basin, which.

2:05 Speaker 1: Is for listeners who haven't heard of it, a nearly

2:08 Speaker 1: six hundred mile wide impact crater that straddles the boundary

2:13 Speaker 1: between the near and far sides of the Moon three

2:16 Speaker 1: point eight billion years old. The Artemis two crew will

2:20 Speaker 1: be the first humans to see it from multiple angles

2:23 Speaker 1: as they swing around.

2:25 Speaker 2: They also found time for some cru selfies using one

2:28 Speaker 2: of Orion's solar array cameras. Very relatable astronauts. They're just

2:33 Speaker 2: like us. Day five, the crew woke up to see

2:36 Speaker 2: low Green's working class Heroes, which feels about right for

2:40 Speaker 2: people who are about to fly around the Moon.

2:44 Speaker 1: Very appropriate playlist choice from mission control.

2:47 Speaker 2: The main objective on Sunday was a full evaluation of

2:50 Speaker 2: the Orion Crue survival suit. All four crew members put

2:54 Speaker 2: on the suits, pressurized them, did leak checks, simulated seat entry,

2:59 Speaker 2: and tested whether they could eat and drink while wearing them.

3:03 Speaker 1: That last one matters more than it might sound. If

3:06 Speaker 1: there's ever a cabin emergency on a future mission and

3:09 Speaker 1: the crew has to suit up quickly, they need to

3:12 Speaker 1: know they can sustain themselves in the suit for an

3:14 Speaker 1: extended period.

3:16 Speaker 2: Later on Sunday, mission control completed a short trajectory correction

3:20 Speaker 2: burn seventeen and a half seconds to fine tune or

3:23 Speaker 2: Ryan's path to the Moon.

3:25 Speaker 1: And then just after midnight Eastern Time on Monday morning,

3:28 Speaker 1: so very early today, the spacecraft entered the Moon's gravitational

3:33 Speaker 1: sphere of influence. Lunar gravity now has more pull on

3:36 Speaker 1: Orion than Earth's does, the.

3:39 Speaker 2: First humans in that position since the Apollo.

3:41 Speaker 1: Era, and so to today. Flight Day six the main event.

3:47 Speaker 2: The six hour fly by window runs from two forty

3:50 Speaker 2: five to nine forty pm Eastern. Depending on when you're

3:53 Speaker 2: listening to this, the crew may already be deep into it.

3:57 Speaker 1: Closest approach is at around seven pm Eastern, four thousand

4:01 Speaker 1: and sixty six miles above the surface, far enough out

4:05 Speaker 1: to see the entire lunar disc at once, including regions

4:09 Speaker 1: near both poles that Apollo astronauts never had this view of.

4:13 Speaker 2: And here's the record that gets broken. Today. At seven

4:17 Speaker 2: oh five pm Eastern, Orion will reach its maximum distance

4:21 Speaker 2: from Earth two hundred and fifty two thousand, seven hundred

4:25 Speaker 2: and fifty seven miles.

4:26 Speaker 1: Beating Apollo thirteen's record by four thousand, one hundred and

4:30 Speaker 1: two miles. Apollo thirteen, the mission that survived an explosion

4:35 Speaker 1: in deep space and used the Moon's gravity to slingshot

4:39 Speaker 1: back to Earth, held that record for fifty six years.

4:43 Speaker 2: There will also be a communications blackout when Orion passes

4:47 Speaker 2: behind the Moon. Signals between the spacecraft and NASA's Deep

4:51 Speaker 2: Space network are blocked. That blackout begins around five forty

4:55 Speaker 2: seven pm Eastern and lasts about forty minutes.

5:00 Speaker 1: Nor Mole expected nothing to worry about. It happened on

5:03 Speaker 1: Artemis one and on every Apollo mission two, but it

5:07 Speaker 1: does mean mission control is briefly out of contact with

5:11 Speaker 1: the crew while they're on the far side.

5:13 Speaker 2: One more thing for today, the crew are attempting to

5:16 Speaker 2: recreate one of the most famous photographs in history. Apollo

5:20 Speaker 2: eates earth Rise, the image of Earth rising above the

5:24 Speaker 2: Moon's horizon, taken on Christmas Eve nineteen sixty eight, one

5:28 Speaker 2: of the most iconic images ever made.

5:32 Speaker 1: Well see if they can match it. My money is

5:34 Speaker 1: on yes.

5:36 Speaker 2: We'll be watching splashdown for the full mission is on

5:39 Speaker 2: track for Friday, April tenth, off San Diego.

5:42 Speaker 1: All right, we promised you this one on Saturday, and

5:45 Speaker 1: we're going to deliver.

5:46 Speaker 2: Comet maps D twenty twenty six A one maps discovered

5:52 Speaker 2: on the thirteenth of January this year in the AMAX

5:56 Speaker 2: one Observatory in Chile's Atakama Desert. Why it's Sungrazer, a

6:01 Speaker 2: family of comets that plunge extremely close to the Sun

6:04 Speaker 2: on very elongated.

6:06 Speaker 1: Orbits, and maps was special. Even within that family, it

6:10 Speaker 1: holds the distinction of being the earliest discovered cruits Sungrazer

6:15 Speaker 1: ever found spotted more than two astronomical units from the Sun,

6:20 Speaker 1: giving astronomers months to track its approach.

6:23 Speaker 2: On Saturday, April fourth, Maps reached Perihelion, its closest point

6:28 Speaker 2: to the Sun. It passed approximately ninety nine thousand miles

6:32 Speaker 2: from the solar surface. To put that in perspective, the

6:35 Speaker 2: diameter of the Sun itself is eight hundred and sixty

6:39 Speaker 2: five thousand miles.

6:41 Speaker 1: It was scorchingly impossibly close.

6:44 Speaker 2: Some were calling it the Easter Comet, hoping it would

6:47 Speaker 2: emerge from that encounter blazing in the post Perihelian sky.

6:52 Speaker 2: Comets in this family have done it before. Iks Seki

6:55 Speaker 2: in nineteen sixty five survived and became one of the

6:58 Speaker 2: brightest comets of the twin century. Comet Lovejoy in twenty

7:02 Speaker 2: eleven survived and became a spectacular naked eye.

7:06 Speaker 1: Object, but Maps didn't make it.

7:09 Speaker 2: About six hours before pery Helian, coronagraph images from the

7:13 Speaker 2: Soho spacecraft showed it at a round magnitude negative zero

7:17 Speaker 2: point six and brightening, Then shortly after it disintegrated. It

7:23 Speaker 2: never re emerged from behind the Sun, though.

7:26 Speaker 1: A spectacular death, if not the spectacular survival we were

7:30 Speaker 1: hoping for. The question now is whether any ghostly debristail remains,

7:35 Speaker 1: but if it does, it would be faint and short lived.

7:38 Speaker 2: It's worth sitting with us for a moment. Mapps was

7:41 Speaker 2: a fragment of a comet that last visited the Inner

7:43 Speaker 2: Solar System roughly seventeen hundred years ago, possibly connected to

7:48 Speaker 2: a comet witnessed in broad daylight in the year three

7:51 Speaker 2: hundred and sixty three AD, documented by the historian Ammanilius Marcellinus.

7:56 Speaker 2: It made it all the way back, and the sun

8:00 Speaker 2: hook it.

8:00 Speaker 1: There is a silver lining, though, Comet C. Twenty twenty

8:04 Speaker 1: five R three pan Stars is brightening and putting on

8:07 Speaker 1: its own show. This month, April seventeenth is your best

8:11 Speaker 1: viewing opportunity. You'll need binoculars. It should reach around magnitude eight,

8:16 Speaker 1: but look east before dawn in the constellations Pegasus and Pisces.

8:21 Speaker 1: We'll keep you updated.

8:22 Speaker 2: Rest well.

8:23 Speaker 1: Maps Now to some deep cosmology that genuinely shakes the

8:27 Speaker 1: foundations of how we think galaxies work.

8:30 Speaker 2: So the standard model of galaxy formation says dark matter

8:34 Speaker 2: is the invisible scaffolding that holds galaxies together without its

8:39 Speaker 2: gravitational pool. The rotational forces of a galaxy stars would

8:43 Speaker 2: simply cause it to fly apart.

8:45 Speaker 1: Dark matter makes up the vast majority of a galaxy's mass.

8:49 Speaker 1: We can't see it, it doesn't interact with light, but

8:53 Speaker 1: we infer it everywhere we look. Until in twenty eighteen,

8:57 Speaker 1: a team at Yale led by astronomer Peter von Dockam

9:01 Speaker 1: found something that shouldn't exist.

9:04 Speaker 2: A galaxy with virtually no dark matter NGC ten fifty

9:08 Speaker 2: two DASH DF two, an ultra diffuse galaxy faint spread

9:14 Speaker 2: out c through almost and the stars inside it were

9:17 Speaker 2: moving far too slowly. There wasn't enough mass the dark

9:21 Speaker 2: matter was missing.

9:23 Speaker 1: Then they found a second one, NNGC ten fifty two

9:27 Speaker 1: DASH DF four, same thing, and both galaxies appeared to

9:32 Speaker 1: lie along the same trail in space, and.

9:35 Speaker 2: Now announced this week a third NNGC ten fifty two

9:39 Speaker 2: DASH DF nine, which falls directly on that same trail

9:43 Speaker 2: between DF two and DF four. The team used a

9:47 Speaker 2: Keck observatory in Hawaii to measure how fast the stars

9:50 Speaker 2: inside DF nine are moving, and the result was the same.

9:54 Speaker 2: No dark matter required to explain the dynamics.

9:57 Speaker 1: Three in a row on the same lene, that is

10:01 Speaker 1: not a coincidence.

10:02 Speaker 2: The explanation the team favors is the bullet dwarf collision theory.

10:07 Speaker 2: Imagine two gas rich dwarf galaxies hurtling toward each other

10:10 Speaker 2: at enormous speed. They collide. The stars, which interact electromagnetically,

10:16 Speaker 2: get tangled up and slow down, but dark matter only

10:19 Speaker 2: interacts via gravity. The dark matter halos of each galaxy

10:23 Speaker 2: just passed straight through each other, like ghosts.

10:26 Speaker 1: What's left behind is a trail of star rich galaxies

10:29 Speaker 1: that have been completely stripped of their dark matter DF two,

10:33 Speaker 1: D four, DF nine, all born from the same catastrophic

10:37 Speaker 1: ancient collision.

10:38 Speaker 2: The team wants to measure a fourth and fifth galaxy

10:41 Speaker 2: on the same trail. The farther out they go, the

10:44 Speaker 2: fainter the targets get. But if they find the same signature,

10:48 Speaker 2: that's about as close to a smoking gun as cosmology.

10:51 Speaker 1: Gets, and what it tells us is profound dark matter exists,

10:56 Speaker 1: but it doesn't have to be everywhere. Galaxies can form

10:59 Speaker 1: and persist without it under the right or rather the

11:02 Speaker 1: extremely violent circumstances.

11:05 Speaker 2: Our next two stories today share something in common. Both

11:09 Speaker 2: involve new tools and new algorithms revealing hitting populations of

11:13 Speaker 2: objects at a scale that simply wasn't possible before. The universe,

11:17 Speaker 2: it turns out, has been holding out on.

11:19 Speaker 1: Us, starting with our own galaxy. Astronomers at the University

11:23 Speaker 1: of Michigan have just announced the discovery of eighty seven

11:26 Speaker 1: new stellar stream candidates in the outskirts of the Milky Way.

11:30 Speaker 2: Now stellar streams for listeners who haven't come across them before.

11:34 Speaker 2: Stellar streams are when a compact cluster of stars travels

11:38 Speaker 2: through the Milky Way's gravitational field. The galaxy slowly pulls

11:42 Speaker 2: stars away from it. Those stars get stretched out into long,

11:46 Speaker 2: trailing ribbons, barking threads of light following the cluster's orbital path.

11:51 Speaker 1: Study co author Oleg Neettin put it beautifully. He said,

11:55 Speaker 1: it's like riding a bike with a bag of sand,

11:57 Speaker 1: where the bag has a hole in it, the sand

11:59 Speaker 1: spilling out behind you. That's the stellar stream.

12:02 Speaker 2: Before the study, fewer than twenty of these streams had

12:05 Speaker 2: been found, and most of those were discovered by chance

12:08 Speaker 2: astronomer stumbling across them in Gaya data while looking for

12:12 Speaker 2: other things.

12:13 Speaker 1: Lead researcher Yin Tanchen, who goes by Bill, took a

12:16 Speaker 1: more systematic approach. He developed a new algorithm called star

12:20 Speaker 1: stream which uses a physics based model of how these

12:23 Speaker 1: streams actually form rather than just looking for visual patterns

12:27 Speaker 1: in the data, and he turned it loose on the

12:29 Speaker 1: full Gaya data set.

12:30 Speaker 2: The result eighty seven candidates, more than quadrupling the known

12:35 Speaker 2: population in one go, and these are the rarest kind

12:39 Speaker 2: streams from globular clusters that are still intact. You can

12:42 Speaker 2: compare the stream directly to its parent cluster, which makes

12:46 Speaker 2: them enormously scientifically valuable.

12:48 Speaker 1: Because the shapes and sizes of these streams encode information

12:52 Speaker 1: about the forces they've experienced, and that tells you about

12:55 Speaker 1: the Milky Way's mass distribution, including how its dark matter

12:59 Speaker 1: halo is structured.

13:00 Speaker 2: So these ribbons of stars are essentially a map of

13:04 Speaker 2: invisible matter. The next step is follow up with more

13:08 Speaker 2: powerful instruments NASA's Roman Space Telescope, Ruben Observatory, and DIESI

13:14 Speaker 2: to verify which of the eighty seven are real streams

13:18 Speaker 2: and which might be background.

13:20 Speaker 1: Noise, which brings us rather neatly to Ruben Observatory.

13:24 Speaker 2: The via C Reuben Observatory, which we've mentioned a few

13:27 Speaker 2: times in the last couple of months as it was

13:30 Speaker 2: coming online, has just released its first major data set,

13:34 Speaker 2: and the numbers are staggering.

13:37 Speaker 1: In six weeks, six weeks of early engineering quality data,

13:41 Speaker 1: not even full science operations, yet, Rubin found over eleven

13:44 Speaker 1: thousand new asteroids, generated nearly a million measurements, and refine

13:49 Speaker 1: the orbits of more than eighty thousand previously cataloged objects.

13:53 Speaker 2: Some of those eighty thousand had effectively vanished from tracking

13:57 Speaker 2: systems because their orbits were two uncertain Ruben recovered them

14:01 Speaker 2: with far greater precision. Objects that were lost found again.

14:06 Speaker 1: Mario Jerrich, the Ruben Solar System lead scientists to the

14:10 Speaker 1: University of Washington, summed it up well, he said, and

14:13 Speaker 1: I'm paraphrasing. This first submission is just the tip of

14:16 Speaker 1: the iceberg. What used to take years or decades to

14:19 Speaker 1: discover Ruben will unearth in months.

14:22 Speaker 2: Among the new finds are thirty three near Earth objects

14:26 Speaker 2: asteroids whose orbits bring them relatively close to Earth's None

14:30 Speaker 2: of them pose any threat, and the largest is about

14:33 Speaker 2: five hundred meters across. But here's the sobering context. Scientists

14:39 Speaker 2: estimate that only forty percent of mid sized near Earth objects,

14:44 Speaker 2: those larger than one hundred and forty meters large enough

14:47 Speaker 2: to cause serious regional damage have been found so.

14:50 Speaker 1: Far forty percent. We're more than halfway to knowing what's

14:54 Speaker 1: out there in that size range, but only barely. Ruben

14:57 Speaker 1: is expected to discover up to ninety thousand additional near

15:01 Speaker 1: Earth objects once fully operational, potentially doubling the known population.

15:06 Speaker 2: The early data set also turned up around three hundred

15:09 Speaker 2: and eighty trans Neptunian objects icy bodies far beyond Neptune.

15:15 Speaker 2: Two of them have highly elongated orbits that carry them

15:18 Speaker 2: as far as one thousand times the Earth Sun distance,

15:22 Speaker 2: among the most distant known objects in the entire Solar System.

15:26 Speaker 1: And this is still just the beginning. When the Legacy

15:29 Speaker 1: Survey of Space and Time the LSST begins full operations,

15:33 Speaker 1: Reuben is expected to find tens of thousands of asteroids

15:37 Speaker 1: every few nights. Over a decade, the known asteroid population

15:41 Speaker 1: could triple.

15:42 Speaker 2: We are entering an arrow where the Solar System becomes

15:45 Speaker 2: a continuously monitored environment rather than a partially mapped frontier.

15:51 Speaker 2: That's an extraordinary shift.

15:53 Speaker 1: And it has real implications for planetary defense. More objects

15:57 Speaker 1: found earlier means more lead time to respond if something

16:00 Speaker 1: concerning turns up.

16:01 Speaker 2: Nothing concerning has turned up, but now we have the

16:04 Speaker 2: tools to know much sooner if it does.

16:07 Speaker 1: We want to close today with something that hasn't happened before,

16:11 Speaker 1: not just in the history of space exploration, in the

16:14 Speaker 1: history of human experience.

16:16 Speaker 2: Tonight, toward the end of the lunar fly by window,

16:19 Speaker 2: the Sun will pass behind the Moon from the perspective

16:23 Speaker 2: of the Orion spacecraft, a solar eclipse lasting nearly an hour.

16:29 Speaker 1: From beyond the Moon's far side.

16:31 Speaker 2: No human being has ever seen that the Apollo cruse

16:35 Speaker 2: flew much closer to the lunar surface. They didn't have

16:38 Speaker 2: this vantage point during this eclipse. Read Wiseman, Victor Glover,

16:43 Speaker 2: Christina Cock, and Jeremy Hansen will be in near total darkness,

16:48 Speaker 2: floating in deep space, with the Moon blocking the Sun

16:52 Speaker 2: above them and the Earth a quarter million miles away.

16:55 Speaker 1: And they'll be working during that darkness. The crew will

16:59 Speaker 1: search for media erroid impact flashes on the lunar surface,

17:02 Speaker 1: brief flickers of light when space rocks strike the Moon.

17:06 Speaker 1: They'll look for dust lofting above the lunar limb. They'll

17:09 Speaker 1: observe deep space targets, planets visible only because the Sun

17:13 Speaker 1: is hidden.

17:14 Speaker 2: Science that can only be done in that moment from

17:18 Speaker 2: that place.

17:19 Speaker 1: There's a symmetry to today's episode that I keep coming

17:23 Speaker 1: back to. We opened with the crew photographing the Moon's

17:26 Speaker 1: ancient geology in the light. We're closing with them watching

17:30 Speaker 1: the Moon swallow the sun in the dark.

17:34 Speaker 2: Fifty three years ago. The last humans to come this

17:36 Speaker 2: far were the crew of Apollo seventeen, Jean Cernon, Harrison Smith,

17:41 Speaker 2: Ronald Evans. They left the Moon on December fourteenth, nineteen

17:45 Speaker 2: seventy two. Sternan was the last person to walk on

17:49 Speaker 2: the lunar surface. Before he climbed back into the lander,

17:52 Speaker 2: he said, we leave as we came, and God willing

17:55 Speaker 2: as we shall return with peace and hope for all mankind.

18:00 Speaker 1: Today we returned.

18:02 Speaker 2: Today we returned. Blashdown is Friday, April tenth, twenty twenty six.

18:08 Speaker 2: We'll be with you every step of the way.

18:10 Speaker 1: That's Astronomy Daily for Monday, the sixth of April twenty

18:14 Speaker 1: twenty six, Season five, episode eighty two.

18:18 Speaker 2: Thank you for spending this time with us. If today's

18:21 Speaker 2: episode moved you, and I think it might have, share

18:24 Speaker 2: it with someone. Tell them humans are flying around the

18:27 Speaker 2: Moon again, because they are.

18:29 Speaker 1: You can find us at Astronomy Daily dot io, and

18:32 Speaker 1: we're at astro Daily Pod across x, Instagram, TikTok, YouTube,

18:38 Speaker 1: and Tumbler.

18:39 Speaker 2: We'll be back tomorrow with Day seven of the Artemis

18:42 Speaker 2: two mission and whatever else the universe throws at us.

18:45 Speaker 2: Until then, keep looking up clear skies, everyone.

18:49 Speaker 3: Sunday Stars. The story is the soul. The story is

19:09 Speaker 3: the Soul.

19:12 Speaker 1: M