S03E118: Meteorites and the Moon's Atmosphere

0:02 Speaker 1: Welcome to Astronomy Daily, your go to podcast for the

0:05 Speaker 1: latest news and discoveries in space and astronomy. I'm your

0:08 Speaker 1: host Anna. Today we have some exciting stories lined up

0:11 Speaker 1: for you. We'll dive into new research on our Moon's atmosphere,

0:14 Speaker 1: revealing the powerful effects of meteorite impacts. Next, we'll explore

0:18 Speaker 1: why detecting signs of advanced extraterrestrial civilizations known as techno signatures,

0:24 Speaker 1: is more challenging than we might think. Finally, we'll uncover

0:27 Speaker 1: recent findings about potential dark matter objects in space, discovered

0:31 Speaker 1: using pulsars. So sit back, relax, and let's embark on

0:35 Speaker 1: this cosmic journey together. NASA astronauts from the Apollo missions

0:42 Speaker 1: uncovered a fascinating aspect of the Moon that was previously unknown.

0:46 Speaker 1: It has an atmosphere, although it's incredibly thin, so much

0:50 Speaker 1: so that it's technically classified as an exosphere. But what

0:54 Speaker 1: drives this tenuous lunar atmosphere. Recent research is pointing to

0:58 Speaker 1: meteorite impacts as primary cause. When meteorites, whether large or small,

1:03 Speaker 1: collide with the Moon's surface, they generate extremely high temperatures

1:07 Speaker 1: ranging from two thousand to six thousand degrees celsius. This

1:11 Speaker 1: intense heat is enough to melt and vaporize the lunar rocks,

1:15 Speaker 1: releasing atoms into the atmosphere. This process is somewhat similar

1:19 Speaker 1: to how water vaporizes when it's heated here on Earth.

1:23 Speaker 1: To get a better understanding, NASA sent the Lunar Atmosphere

1:26 Speaker 1: and Dust Environment Explorer, or LADY, to orbit the Moon.

1:29 Speaker 1: Back in twenty thirteen. Lay D confirmed that two main

1:33 Speaker 1: processes are at work, meteorite impacts and something known as

1:37 Speaker 1: solar wind sputtering. Solar winds, which are streams of charged

1:41 Speaker 1: particles from the Sun, transfer energy to atoms on the

1:44 Speaker 1: Moon's surface, causing them to be ejected into the atmosphere. However,

1:48 Speaker 1: recent studies have shown that meteorite impacts account for more

1:52 Speaker 1: than seventy percent of the lunar atmosphere's composition, while solar

1:56 Speaker 1: wind sputtering contributes less than thirty percent. The The Moon

2:00 Speaker 1: has been bombarded by meteorites throughout its history. Early on,

2:04 Speaker 1: these impacts led to the formation of the large craters

2:07 Speaker 1: we can see on its surface today. More recently, smaller impacts,

2:10 Speaker 1: including micrometeorites, continue to shower the Moon, replenishing its atmosphere.

2:16 Speaker 1: Some of the atoms released by these impacts escape into space,

2:19 Speaker 1: but many remain suspended above the lunar surface. Interestingly, this

2:24 Speaker 1: thin lunar atmosphere mainly contains elements like argon, helium, and neon,

2:29 Speaker 1: along with traces of potassium and rubidium. Unlike Earth's atmosphere,

2:34 Speaker 1: which extends to approximately six thou two hundred miles above

2:37 Speaker 1: the surface, the Moon's atmosphere only reaches about sixty two

2:40 Speaker 1: miles high. Researchers use lunar soil or regolith as a

2:45 Speaker 1: proxy to study the atoms in the lunar atmosphere. By

2:48 Speaker 1: examining the ratios of different isotopes of potassium and rubidium

2:52 Speaker 1: in the soil with a mass spectrometer, they were able

2:55 Speaker 1: to trace the sources of these atoms and determine their

2:58 Speaker 1: contributions to the atmosphere. These isotopes act as historical records,

3:04 Speaker 1: preserving the imprints of the processes that have shaped the

3:07 Speaker 1: Moon's atmosphere since its formation. Despite all the data collected

3:12 Speaker 1: over the years, many questions about the lunar atmosphere remain unanswered.

3:17 Speaker 1: Advances in technology, especially in the precision of mass spectrometers,

3:21 Speaker 1: are enabling scientists to gain new insights. As planetary scientist

3:25 Speaker 1: Nicolene from MIT explained, when Apollo samples were returned from

3:30 Speaker 1: the Moon in the nineteen seventies, the isotopic compositions of

3:34 Speaker 1: potassium and rubidium in lunar soils were measured, but no

3:37 Speaker 1: differences were observed. Today's mass spectrometers offer much greater precision.

3:43 Speaker 1: This research not only sheds light on the processes shaping

3:46 Speaker 1: the Moon's atmosphere, but also helps us understand the broader

3:49 Speaker 1: dynamics at play on other celestial bodies. As we continue

3:53 Speaker 1: to study the Moon, each new discovery adds another piece

3:56 Speaker 1: to the puzzle of our cosmic neighborhood. NASA scientists have

4:02 Speaker 1: been delving into the intriguing question of why we might

4:05 Speaker 1: not be able to detect advanced extraterrestrial civilizations, also known

4:09 Speaker 1: as techno signatures. One prevailing theory suggests that these civilizations

4:13 Speaker 1: may have relatively modest energy requirements, which means they wouldn't

4:17 Speaker 1: necessarily need to construct vast, detectable stellar energy structures like

4:23 Speaker 1: enormous solar panel arrays that cover their planet's surface or

4:27 Speaker 1: giant orbiting megastructures to harvest energy from their star. Let's imagine,

4:31 Speaker 1: for instance, an advanced alien civilization running on sustainable energy,

4:36 Speaker 1: much like the direction we're headed here on Earth. NASA

4:39 Speaker 1: researchers pointed out that even if humanity's population were to

4:42 Speaker 1: stabilize at thirty billion, with a high standard of living

4:46 Speaker 1: relying solely on solar energy, that would still only require

4:49 Speaker 1: a fraction about eight point nine percent of Earth's land

4:53 Speaker 1: to be covered with solar panels. It's a perspective that

4:56 Speaker 1: could explain why our telescopes haven't picked up on any

4:59 Speaker 1: massive nat energy structures in space. Doctor Ravi Kopporapu from

5:04 Speaker 1: NASA's Goddard Space Flight Center, who led the study, explained

5:07 Speaker 1: that their simulations show civilizations might not need galaxy spanning

5:11 Speaker 1: energy solutions. If they achieve a sustainable balance of population

5:15 Speaker 1: and energy use, they might not feel any urgent drive

5:18 Speaker 1: to expand across the galaxy. Instead, they could be content

5:22 Speaker 1: thriving within their own stellar system or just reaching out

5:26 Speaker 1: to a few neighboring stars. Additionally, our current technological understanding

5:31 Speaker 1: might not yet offer the complete picture of what advanced

5:34 Speaker 1: extraterrestrial tech looks like. Take, for example, huge stellar energy

5:38 Speaker 1: harvesting structures often depicted in science fiction. These could be

5:43 Speaker 1: obsolete for an advanced civilization that has access to other

5:46 Speaker 1: space efficient power sources like nuclear fusion. Doctor Vincent Kaufman,

5:51 Speaker 1: one of the co authors of the study, noted that

5:54 Speaker 1: a society capable of deploying massive megastructures would likely have

5:58 Speaker 1: already developed more advance its power generation techniques that are

6:02 Speaker 1: beyond our current grasp. To put this theory to the test,

6:06 Speaker 1: the team used computer models and satellite data to simulate

6:09 Speaker 1: how an earthlike planet with different levels of solar panel

6:12 Speaker 1: coverage might appear using an advanced telescope such as the

6:16 Speaker 1: proposed NASA Habitable World's Observatory. The results showed that detecting

6:21 Speaker 1: solar panels on a distant exoplanet, even those covering a

6:25 Speaker 1: significant portion of it, would demand hundreds of hours of

6:29 Speaker 1: observing time with this kind of telescope. This highlights just

6:32 Speaker 1: how challenging it is to identify these subtle technosignatures. This

6:37 Speaker 1: research carries significant implications for the Fermi paradox, which asks why,

6:41 Speaker 1: with our galaxies age and vastness, we haven't yet observed

6:45 Speaker 1: evidence of alien civilizations. One reason might be that these

6:49 Speaker 1: civilizations achieve a sustainable small scale energy balance and thus

6:53 Speaker 1: remain largely undetectable with our current methodologies. Furthermore, the researchers

6:59 Speaker 1: hypothesized that if extraterrestrial civilizations are similar to us in

7:03 Speaker 1: their reliance on silicon for solar panels, it would make

7:06 Speaker 1: detection easier since silicon is efficient and relatively abundant. However,

7:11 Speaker 1: if they utilize more advanced or alternate energy sources, the

7:15 Speaker 1: task becomes even more challenging. Ultimately, the study provides a

7:18 Speaker 1: thought provoking reminder of the limits of our current technology

7:22 Speaker 1: and understanding when it comes to finding signs of extraterrestrial life.

7:27 Speaker 1: It's fascinating to consider that the very reason we might

7:30 Speaker 1: not be able to detect these civilizations is because they

7:33 Speaker 1: have already solved some of the sustainability challenges we are

7:37 Speaker 1: only beginning to address. This exploration into technos signatures pushes

7:42 Speaker 1: the boundaries of how we think about and search for

7:44 Speaker 1: life beyond our planet, making the quest all the more exciting.

7:51 Speaker 1: Recent research has brought exciting news in our quest to

7:53 Speaker 1: understand dark matter, something that has intrigued astronomers for decades.

7:58 Speaker 1: The study involves pulsars, which are neutron stars known for

8:01 Speaker 1: emitting regular beams of radio waves. These pulsars act like

8:05 Speaker 1: cosmic lighthouses, regularly sweeping their beams through space. By leveraging

8:10 Speaker 1: the precision of their timing, scientists have detected potential dark

8:14 Speaker 1: matter objects. Pulsars are sometimes referred to as the universe's

8:18 Speaker 1: timekeepers because of their incredibly consistent and predictable emissions. This

8:23 Speaker 1: quality makes them perfect candidates for detecting variations caused by

8:27 Speaker 1: external influences such as unseen masses, including dark matter. So

8:32 Speaker 1: here's where it gets fascinating. Professor John LESCo of the

8:36 Speaker 1: University of Notre Dame studied data from the Park's Pulsar

8:39 Speaker 1: Timing Array Survey, which includes precise measurements from several radio

8:43 Speaker 1: telescopes around the world. By doing so, he found variations

8:47 Speaker 1: and delays in pulsor signal timings that suggest the presence

8:50 Speaker 1: of dark matter. What does this mean, Well, gravity has

8:54 Speaker 1: been known to slow down light for over a century,

8:57 Speaker 1: but applying this concept to pulsar timing is a novel approach.

9:00 Speaker 1: According to Professor Losseco, these variations indicate that the radio

9:04 Speaker 1: beams are traveling around something massive but invisible, likely dark matter.

9:09 Speaker 1: By measuring the delays in the arrival times of these

9:12 Speaker 1: radio pulses, which usually clock in with nanosecond accuracy. He

9:16 Speaker 1: was able to pinpoint around a dozen incidents where dark

9:19 Speaker 1: matter seems to have influenced the pulsar signals. But let's

9:23 Speaker 1: get into the specifics. When a mass as significant as

9:27 Speaker 1: the Sun interacts with these radio beams, it can cause

9:30 Speaker 1: a delay of about ten microseconds in their arrival times. Remember,

9:35 Speaker 1: the data professor Losseco analyzed had a resolution at the

9:38 Speaker 1: nanosecond level, which is ten thousand times smaller. One of

9:43 Speaker 1: his findings even points to a distortion equivalent to about

9:46 Speaker 1: twenty percent of the Sun's mass. This research doesn't just

9:50 Speaker 1: add to our understanding of dark matter, it also improves

9:53 Speaker 1: pulser timing data, which has broader astronomical applications. Pulser timing

9:59 Speaker 1: arrays like the one used in this study are also

10:02 Speaker 1: looking for evidence of low frequency gravitational waves. Dark matter

10:07 Speaker 1: objects add what we call noise to the data, so

10:10 Speaker 1: identifying and removing their influence can make other astronomical observations

10:15 Speaker 1: more accurate and reliable. What's particularly exciting is that this

10:19 Speaker 1: refined pulsar data can be used to hunt for other

10:21 Speaker 1: phenomena in the universe. By better understanding and accounting for

10:25 Speaker 1: the influence of dark matter, astronomers can clean up the data,

10:29 Speaker 1: enhancing its precision and perhaps leading to more groundbreaking discoveries.

10:34 Speaker 1: The true nature of dark matter remains one of the

10:36 Speaker 1: most intriguing mysteries in modern astrophysics. This research by Professor

10:41 Speaker 1: Losseco adds a significant piece to the puzzle, shedding light

10:45 Speaker 1: on its distribution in our galaxy and potentially helping to

10:48 Speaker 1: decipher what it is. That wraps up today's episode of

10:55 Speaker 1: Astronomy Daily, I've been your host Anna. If you enjoyed

10:58 Speaker 1: today's show, to visit our website at Astronomy Daily dot io.

11:02 Speaker 1: Until next time, keep looking.

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