The Sun's Great Galactic Road Trip, China's Moon Museum & a Pi Day Planet

0:00 Speaker 1: Happy Pie day space fans three point one four one,

0:04 Speaker 1: five nine and counting. Yes, it's March fourteenth. And if

0:08 Speaker 1: that sounds like an excuse to talk about an exoplanet

0:11 Speaker 1: with a three point one four day year, that's because

0:14 Speaker 1: it absolutely is.

0:16 Speaker 2: But before we get to our cosmic pie celebration, we

0:20 Speaker 2: have a packed episode, a story about where our own

0:23 Speaker 2: son came from, a big announcement about where China's astronauts

0:26 Speaker 2: might first set foot on the Moon, and Russia's bold

0:29 Speaker 2: plan to pick up where the Soviet Union left off

0:32 Speaker 2: at Venus.

0:33 Speaker 1: Plus a nuclear powered flying drone for Saturn's moon Titan

0:38 Speaker 1: is now actually being built, and China's race to beat

0:41 Speaker 1: everyone to a Martian soil sample is well and truly underway.

0:46 Speaker 1: I'm Avery and I'm Ana. This is Astronomy Daily, Season five,

0:51 Speaker 1: episode sixty three. Let's get into it.

0:54 Speaker 2: Here's a question that sounds simple but turns out to

0:57 Speaker 2: be surprisingly deep. How did our own own sun end

1:00 Speaker 2: up where it is in the Milky Way?

1:02 Speaker 1: Right? I mean, you might assume it just formed where

1:05 Speaker 1: it is, but the evidence has been pointing somewhere else

1:09 Speaker 1: for a while. And a new study published this week

1:11 Speaker 1: in Astronomy and astrophysics might finally have the answer, and

1:15 Speaker 1: it involves thousands of stars traveling together.

1:19 Speaker 2: Researchers at Tokyo Metropolitan University and the National Astronomical Observatory

1:24 Speaker 2: of Japan built the largest ever catalog of what are

1:27 Speaker 2: called solar twins, stars so similar to our Sun in temperature, mass,

1:32 Speaker 2: chemical composition, and surface gravity that they're essentially its cousins.

1:37 Speaker 1: They compiled six thousand, five hundred and ninety four solar twins,

1:42 Speaker 1: which is a staggering number when you think about how

1:45 Speaker 1: special we tend to think our Sun is, and they.

1:48 Speaker 2: Used ESA's Gaya satellite data to determine two things about

1:51 Speaker 2: each star, how old it is and where it has

1:54 Speaker 2: been moving. What they found was a striking pattern. A

1:57 Speaker 2: large number of these solar twins are between four and

2:00 Speaker 2: six billion years old, which is the same age bracket

2:03 Speaker 2: as her own Sun.

2:04 Speaker 1: That clustering is not random. It suggests that the Sun

2:08 Speaker 1: and many of these stars formed in the same general

2:11 Speaker 1: region of the galaxy, probably closer to the Milky Way's

2:15 Speaker 1: inner regions, and then gradually drifted outward together over billions

2:19 Speaker 1: of years.

2:20 Speaker 2: But here's the puzzle that the researchers had to solve.

2:23 Speaker 2: The Milky Way has what's called a galactic bar, a

2:27 Speaker 2: rotating bar shaped structure of stars and gas. Near the center.

2:31 Speaker 2: That bar creates something astronomers call a co rotation barrier,

2:36 Speaker 2: which basically traps stars in certain orbital zones and makes

2:39 Speaker 2: it very hard for them to move outward.

2:42 Speaker 1: So how did the Sun escape?

2:44 Speaker 2: The theory is that when the Sun and its companions formed,

2:47 Speaker 2: the galactic bar was still in the process of forming.

2:50 Speaker 2: It wasn't fully developed yet, and the weaker barrier may

2:53 Speaker 2: have allowed whole groups of stars to break out together,

2:56 Speaker 2: carried along by the dynamics of the early galaxy.

2:59 Speaker 1: And the implications of this go beyond just knowing our

3:02 Speaker 1: Sun's origin story. If the Sun formed much closer to

3:06 Speaker 1: the center researchers estimate about ten thousand light years closer

3:10 Speaker 1: than it is today, then this migration may actually be

3:14 Speaker 1: part of the reason Earth became habitable.

3:17 Speaker 2: The galactic center is a harsher place, higher star density,

3:21 Speaker 2: more frequent supernova explosions, more high energy radiation moving outward

3:27 Speaker 2: placed us in a calmer neighborhood, one more complex chemistry

3:31 Speaker 2: and life could hold and persist over billions of years.

3:35 Speaker 1: So our Sun didn't travel alone. It was part of

3:38 Speaker 1: a wave, a kind of ancient stellar migration, and that

3:42 Speaker 1: journey maybe one of the reasons we're here to talk

3:44 Speaker 1: about it.

3:45 Speaker 2: There is a lot to be grateful for in that story.

3:48 Speaker 1: If you've been following the global Moon race, you'll know

3:51 Speaker 1: that China has an ambitious target to land astronauts on

3:55 Speaker 1: the lunar surface by twenty thirty and this week we

3:58 Speaker 1: got the clearest picture yet of where that landing might happen.

4:02 Speaker 2: A new study published in Nature Astronomy has highlighted a

4:05 Speaker 2: region called Remi Bode, a volcanic area near the lunar

4:09 Speaker 2: equator on the Moon's near side, as the leading candidate

4:12 Speaker 2: for China's first crude lunar mission.

4:15 Speaker 1: And the description that researcher June Long from the China

4:19 Speaker 1: University of Geosciences used for it is just perfect. He

4:23 Speaker 1: called it a geological museum.

4:26 Speaker 2: Because within a relatively compact area, Remay Bode contains five

4:30 Speaker 2: distinct terrain types, ancient pyroclastic deposits from volcanic eruptions, smooth

4:36 Speaker 2: mare basalts, two different real systems, which are essentially long

4:41 Speaker 2: channels or cracks in the surface and nearby highland material

4:46 Speaker 2: five completely different chapters of lunar history, all accessible from

4:50 Speaker 2: one landing zone.

4:51 Speaker 1: That's the key point for mission planners. A scientifically rich

4:55 Speaker 1: site is only useful if it's also safe and practical.

5:00 Speaker 1: So what makes Remay Bode attractive is that astronauts could

5:03 Speaker 1: potentially traverse across several very different geological environments without having

5:08 Speaker 1: to travel enormous and risky distances.

5:11 Speaker 2: The researchers dated some of the earliest volcanic activity in

5:15 Speaker 2: the region to roughly three point two to three point

5:18 Speaker 2: seven billion years ago. That's deep lunar history, and those

5:23 Speaker 2: ancient pyroclastic materials could include ash and glass beads thrown

5:27 Speaker 2: up from the Moon's interior, which would be completely different

5:31 Speaker 2: from the rocks returned by the Apollo missions or China's

5:34 Speaker 2: own robotic Chang emissions.

5:36 Speaker 1: This site didn't come out of nowhere. Chinese researchers had

5:40 Speaker 1: originally screened one hundred and six potential landing areas and

5:44 Speaker 1: narrowed them to fourteen candidates based on practical requirements. Mere

5:49 Speaker 1: side location for communication with Earth, access to solar power,

5:53 Speaker 1: and terrain safe enough for landing and surface operations.

5:57 Speaker 2: From that shortlist. The new paper poses four specific landing

6:01 Speaker 2: spots within Remay Bode itself, each offering slightly different scientific

6:06 Speaker 2: priorities while still meeting those safety criteria. The plan also

6:11 Speaker 2: includes the use of an unpressurized rover to travel between

6:15 Speaker 2: geological units, which would dramatically extend the science possible in

6:19 Speaker 2: a single mission.

6:20 Speaker 1: China's crude lunar program is part of a larger sequence

6:24 Speaker 1: that includes Changa seven and Changa eight missions with long

6:28 Speaker 1: term goals around a south polar research station, but Remay

6:32 Speaker 1: Bode as a first landing site makes a lot of

6:35 Speaker 1: sense near side for communications, scientifically diverse and a manageable

6:40 Speaker 1: operating environment.

6:42 Speaker 2: It's still a candidate rather than a confirmed destination, but

6:45 Speaker 2: this is the most specific and scientifically detailed case we've

6:49 Speaker 2: seen yet for where China's first astronauts might set foot

6:53 Speaker 2: on another world.

6:54 Speaker 1: Another country making a big announcement this week, Russia has

6:58 Speaker 1: announced plans to launch emission called Venera D to Venus

7:02 Speaker 1: in twenty thirty six, and it's an ambitious one. We're

7:06 Speaker 1: talking about a lander, a balloon that would float through

7:09 Speaker 1: the Venutian atmosphere, and an orbiter all working together.

7:14 Speaker 2: And the historical context here is remarkable. The Soviet Union

7:19 Speaker 2: is the only nation in history to have successfully landed

7:22 Speaker 2: and operated spacecraft on the surface of Venus. Venera seven

7:26 Speaker 2: did it first back in nineteen seventy, and over the

7:29 Speaker 2: following thirteen years, the Soviets sent a whole series of

7:33 Speaker 2: Venera Landers and orbiters, sixteen missions in total across twenty

7:37 Speaker 2: two years.

7:38 Speaker 1: And when you understand what the surface of Venus is

7:41 Speaker 1: actually like, that achievement becomes even more extraordinary. Surface temperatures

7:47 Speaker 1: around nine hundred degrees fahrenheit, that's four hundred and eighty celsius,

7:52 Speaker 1: atmospheric pressure more than ninety times that of Earth at

7:56 Speaker 1: sea level. It is a genuinely hellish environment.

8:00 Speaker 2: The Soviet Venera Landers didn't just survive, they sent back images.

8:04 Speaker 2: Those photographs of Venus's volcanic rock surface, tinged yellow by

8:08 Speaker 2: the sulfuric acid clouds above, remained some of the most

8:12 Speaker 2: extraordinary images in the history of space exploration.

8:16 Speaker 1: Russia hasn't been to Venus since nineteen eighty three, and

8:19 Speaker 1: Venera D has actually been in planning since two thousand

8:23 Speaker 1: and three. It was at one point even under consideration

8:26 Speaker 1: as a joint mission with NASA before Russia's twenty twenty

8:30 Speaker 1: two invasion of Ukraine ended that kind of collaboration.

8:34 Speaker 2: Russia's first Deputy Prime Minister, Dennis Mantarov confirmed the mission

8:38 Speaker 2: this week, describing Venus, alongside the Moon, as central to

8:42 Speaker 2: russia space ambitions, and one of the naradi's key scientific

8:46 Speaker 2: goals will be searching for signs of microbial life in

8:50 Speaker 2: Venus's clouds.

8:51 Speaker 1: That's not as outlandish as it might sound. The cloud

8:55 Speaker 1: layers of Venus at altitudes of around forty eight to

8:58 Speaker 1: sixty kilometers have temperatures and pressures not unlike those at

9:02 Speaker 1: Earth's surface, and there have been disputed detections of phosphene

9:06 Speaker 1: and ammonia there, both of which could potentially be biological

9:10 Speaker 1: in origin.

9:11 Speaker 2: Russia isn't the only nation looking at Venus right now.

9:14 Speaker 2: Issa's Envision Mission, India's Shukrayon I, and NASA's Da Vinci

9:19 Speaker 2: and Veritas projects are all in various stages of developments.

9:22 Speaker 2: Venus is having a.

9:24 Speaker 1: Moment, and if Fenerade launches in twenty thirty six as planned,

9:28 Speaker 1: it would extend one of the most impressive and now

9:31 Speaker 1: largely forgotten legacies in space exploration history. The Soviets conquered Venus.

9:37 Speaker 1: Russia wants to go back.

9:39 Speaker 2: Now here's a milestone that deserves a moment of appreciation.

9:43 Speaker 2: This week, engineers at the Johns Hopkins Applied Physics Laboratory

9:47 Speaker 2: in Maryland officially began assembling NASA's Dragonfly rotorcraft, the nuclear

9:52 Speaker 2: power drone that will one day fly across the surface

9:56 Speaker 2: of Saturn's moon Titan.

9:58 Speaker 1: This is the point where a mission stopp ops being

10:00 Speaker 1: a plan and starts being a physical thing. Principal investigator

10:04 Speaker 1: Elizabeth Turtle put it perfectly when she said, this milestone

10:09 Speaker 1: essentially marks the birth of our flight system.

10:12 Speaker 2: So what is Dragonfly exactly? It's a car sized eight

10:16 Speaker 2: rotor drone. Think of a very large quad copter, but

10:20 Speaker 2: with eight rotors and four counter rotating pairs. It'll be

10:23 Speaker 2: powered not by solar energy, but by a radio isotope

10:27 Speaker 2: thermoelectric generator, a nuclear power source, because sunlight on Titan

10:32 Speaker 2: is too faint and too inconsistent to be.

10:34 Speaker 1: Useful, and Titan is just a spectacular target. It's Saturn's

10:39 Speaker 1: largest moon, and it's unlike anywhere else we've thought about

10:43 Speaker 1: sending a mission. It has a thick nitrogen atmosphere denser

10:47 Speaker 1: than Earth's, which is actually what makes flying there possible.

10:51 Speaker 1: It has rivers and lakes, but not of water, of

10:54 Speaker 1: liquid methan and ethan. It has complex organic chemistry raining

10:59 Speaker 1: down from in the atmosphere, like a slow chemical snow.

11:03 Speaker 2: Scientists think Titan's surface chemistry might resemble what Earth look

11:07 Speaker 2: like before life emerged, which is exactly why it's so

11:10 Speaker 2: exciting from an astrobiology perspective. Dragonfly will fly to dozens

11:15 Speaker 2: of locations across the surface, stopping to collect and analyze

11:18 Speaker 2: samples as it goes.

11:20 Speaker 1: The first power and functional tests have already been completed

11:24 Speaker 1: on Dragonfly's integrated electronics lodule, its brain, and its power

11:28 Speaker 1: switching units. The aeroshell and cruise stage are being assembled

11:32 Speaker 1: at Lockheed Martin and Colorado, and the wind tunnel testing

11:36 Speaker 1: at NASA Langley has already validated the rotor design.

11:40 Speaker 2: The timeline integration and testing continues at Johns Hopkins through

11:44 Speaker 2: this year and into early twenty twenty seven, then system

11:48 Speaker 2: level testing at Lockheed Martin, then final environmental testing back

11:52 Speaker 2: at Hopkins, before heading to Kennedy Space Center in spring

11:55 Speaker 2: of twenty twenty eight for launch. On a SpaceX Falcon

11:58 Speaker 2: Heavy that summer.

12:00 Speaker 1: Arrival at Titan twenty thirty four, and once there, Dragonfly

12:04 Speaker 1: aims to cover more than one hundred and eight miles

12:08 Speaker 1: of terrain, nearly double the total distance traveled by all

12:11 Speaker 1: Mars rovers combined. It is one of the most audacious

12:15 Speaker 1: planetary missions ever conceived, and this week it became a

12:20 Speaker 1: real spacecraft.

12:21 Speaker 2: More news from China. The race to return samples from

12:25 Speaker 2: Mars is very much on, and this week came confirmation

12:28 Speaker 2: that China's entry in that race is moving from engineering

12:31 Speaker 2: prototypes to real flight hardware.

12:34 Speaker 1: Chief designer Liu j Chung announced at China's annual Two

12:38 Speaker 1: Sessions political meetings on March twelfth that Tianwin three has

12:42 Speaker 1: achieved breakthroughs in all key technologies and now is entering

12:46 Speaker 1: the flight model development phase, meaning they're building the actual

12:50 Speaker 1: spacecraft that will go to Mars.

12:52 Speaker 2: Dion Went three is an enormously complex mission. It involves

12:57 Speaker 2: two separate launches from Earth in late twenty twenty using

13:01 Speaker 2: long March five rockets, the same type that launched China's

13:04 Speaker 2: previous Mars mission and its lunar sample return. One launch

13:08 Speaker 2: carries a lander and acent vehicle. The other carries an

13:12 Speaker 2: orbiter and Earth return spacecraft.

13:15 Speaker 1: The lander touches down on Mars, collects at least five

13:18 Speaker 1: hundred grams of Martian rock and soil using a combination

13:22 Speaker 1: of a scoop, a drill, and a small drone. Then

13:25 Speaker 1: the ascent vehicle launches those samples into Mars orbit. There

13:29 Speaker 1: it rendezvous with the orbiter, which then carries the samples

13:32 Speaker 1: all the way back to Earth. Targeted arrival in twenty

13:35 Speaker 1: thirty one.

13:36 Speaker 2: If successful, that would make Tianwin three the first ever

13:40 Speaker 2: mission to return samples from Mars, and that's important context.

13:45 Speaker 2: NASA's own Mars sample return program was effectively canceled earlier

13:49 Speaker 2: this year when it received no funding in the twenty

13:52 Speaker 2: twenty six appropriations bill.

13:55 Speaker 1: China has narrowed its landing site candidates from one hundred

13:58 Speaker 1: and six down to nineteen, with the final three to

14:01 Speaker 1: be selected by the end of this year. Candidate sites

14:04 Speaker 1: include ancient shorelines, clay mineral rich terrain that could preserve

14:08 Speaker 1: organic molecules, and areas associated with Mars's ancient water systems.

14:13 Speaker 2: The primary scientific goal is the search for biosignatures, potential

14:17 Speaker 2: signs that life once existed. On Mars. The mission is

14:21 Speaker 2: also open to international collaboration, with China inviting partner payloads

14:25 Speaker 2: and promising international sciences access to the return samples.

14:30 Speaker 1: This is a story worth watching very closely. By the

14:33 Speaker 1: time Tianwan's relaunches in twenty twenty eight, it may well

14:37 Speaker 1: be the only active Mars sample return mission on the books.

14:41 Speaker 1: The first Martian soil in a laboratory on Earth could

14:44 Speaker 1: be arriving on a Chinese spacecraft.

14:47 Speaker 2: We'll keep an eye on this one. The geopolitical ramifications,

14:50 Speaker 2: not to mention bragging rights could be quite important, all right.

14:54 Speaker 1: We saved the best for Pyday, and NASA's Astronomy Picture

14:58 Speaker 1: of the Day team clearlyreas with us because today's APOD

15:02 Speaker 1: is dedicated entirely to K two three one five B,

15:05 Speaker 1: the exoplanet with a year that lasts almost exactly three

15:09 Speaker 1: point one four days.

15:11 Speaker 2: K two three one five B was discovered using data

15:14 Speaker 2: from the Kepler Space Telescopes extended K two mission and

15:17 Speaker 2: announced back in twenty twenty. It's an Earth sized world

15:21 Speaker 2: orbiting a cool red dwarf star, an M type star

15:25 Speaker 2: about one hundred and eighty five light years away from US.

15:28 Speaker 1: Now an orbital period of three point one four days

15:31 Speaker 1: means it is very close to its star, very close,

15:35 Speaker 1: which means its surface temperature is absolutely scorching, the kind

15:39 Speaker 1: of baking hot that makes any thoughts of habitability evaporate immediately.

15:44 Speaker 2: But that's fine. K two three point fifteen B is

15:47 Speaker 2: not here to be habitable. It's here to be delightful.

15:50 Speaker 2: Because of all the exo planets we found, and we

15:52 Speaker 2: found thousands, now this one just happens to orbit it

15:56 Speaker 2: star in almost precisely pi days.

15:59 Speaker 1: The precise is genuinely striking. Astronomers measured the orbital period

16:04 Speaker 1: at three point one four one five nine days, which

16:07 Speaker 1: if you had your pie memorized since school, you'll recognize

16:10 Speaker 1: as pie to five decimal places.

16:13 Speaker 2: The universe didn't do that on purpose, obviously, but it's

16:17 Speaker 2: a beautiful coincidence and a wonderful reminder that the cosmos

16:20 Speaker 2: doesn't always have to be profound and weighty. Sometimes it

16:24 Speaker 2: just gives you a planet that celebrates mathematics.

16:27 Speaker 1: So from all of us here at Astronomy Daily, Happy

16:30 Speaker 1: Pie Day. May your circles be perfect and your exoplanets

16:33 Speaker 1: be numerically satisfying.

16:35 Speaker 2: And that wraps up episode sixty three of Astronomy Daily

16:39 Speaker 2: Season five. What a Show Today, Solar Twin Migrations, China's

16:43 Speaker 2: Lunar Museum, Soviet Era, Venus Nostalgia, Nuclear Drones for Titan,

16:49 Speaker 2: the Mars Sample Race, and the Pie Day Cosmic treat.

16:53 Speaker 1: If you enjoyed today's episode, please leave us a review.

16:56 Speaker 1: Wherever you listen, it genuinely makes a difference in helping

16:59 Speaker 1: new listeners find out and share the show with anyone

17:02 Speaker 1: who needs a little more space in their life.

17:04 Speaker 2: You can find us at Astronomy Daily dot io and

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17:16 Speaker 2: on the website.

17:17 Speaker 1: We'll be back on Monday with more of the Universe's

17:20 Speaker 1: greatest hits. Until then, keep looking.

17:23 Speaker 2: Up Sunday Starstzo Starzo