August 21, 2025 • 19 mins
In this episode of SpaceTime, we delve into intriguing new research that challenges our understanding of Earth's climatic history, the discovery of a rare astronomical phenomenon, and China's advancements in lunar exploration.
Did a Comet Trigger the Younger Dryas Cool Off?
A groundbreaking study has emerged suggesting that a massive comet may have instigated Earth's Younger Dryas cool off event, traditionally attributed to glacial meltwater. Analysis of ocean sediments published in the journal PLOS One reveals geochemical clues that support the hypothesis of Earth encountering a disintegrating comet around 12,800 years ago. This event could have led to rapid cooling, with temperatures plummeting by approximately 10 degrees Celsius within a year. The findings indicate a potential link between comet dust and significant climate shifts, inviting further investigation into this captivating theory.
Discovery of a Rare White Dwarf Merger Remnant
Astronomers have identified an ultra-massive white dwarf star resulting from the merger of two stars, rather than the evolution of a single star. This discovery, made possible by NASA's Hubble Space Telescope, suggests that such white dwarf mergers may be more common than previously thought. The object, catalogued as WD0525 526, is located 126 light years away and is about 20% more massive than our Sun. Hubble's ultraviolet observations revealed carbon in its atmosphere, a sign of its violent origin, challenging previous assumptions about white dwarf formation.
China Tests Its New Manned Lunar Lander
In a significant milestone for lunar exploration, China has successfully conducted a test flight of its new manned lunar landing craft, named Lanyu. This test, which included a controlled landing and takeoff, marks a crucial step in China's ambitions to send taikonauts to the Moon by 2030. The Lanyu is designed to carry astronauts from lunar orbit to the surface and back, with plans for a permanent lunar base in collaboration with Russia in the early 2030s.
www.spacetimewithstuartgary.com
✍️ Episode References
PLOS One
https://journals.plos.org/plosone/
Nature Astronomy
https://www.nature.com/natureastronomy/
NASA Hubble Space Telescope
https://www.nasa.gov/mission_pages/hubble/main/index.html
Become a supporter of this podcast: https://www.spreaker.com/podcast/spacetime-space-astronomy--2458531/support.
Did a Comet Trigger the Younger Dryas Cool Off?
A groundbreaking study has emerged suggesting that a massive comet may have instigated Earth's Younger Dryas cool off event, traditionally attributed to glacial meltwater. Analysis of ocean sediments published in the journal PLOS One reveals geochemical clues that support the hypothesis of Earth encountering a disintegrating comet around 12,800 years ago. This event could have led to rapid cooling, with temperatures plummeting by approximately 10 degrees Celsius within a year. The findings indicate a potential link between comet dust and significant climate shifts, inviting further investigation into this captivating theory.
Discovery of a Rare White Dwarf Merger Remnant
Astronomers have identified an ultra-massive white dwarf star resulting from the merger of two stars, rather than the evolution of a single star. This discovery, made possible by NASA's Hubble Space Telescope, suggests that such white dwarf mergers may be more common than previously thought. The object, catalogued as WD0525 526, is located 126 light years away and is about 20% more massive than our Sun. Hubble's ultraviolet observations revealed carbon in its atmosphere, a sign of its violent origin, challenging previous assumptions about white dwarf formation.
China Tests Its New Manned Lunar Lander
In a significant milestone for lunar exploration, China has successfully conducted a test flight of its new manned lunar landing craft, named Lanyu. This test, which included a controlled landing and takeoff, marks a crucial step in China's ambitions to send taikonauts to the Moon by 2030. The Lanyu is designed to carry astronauts from lunar orbit to the surface and back, with plans for a permanent lunar base in collaboration with Russia in the early 2030s.
www.spacetimewithstuartgary.com
✍️ Episode References
PLOS One
https://journals.plos.org/plosone/
Nature Astronomy
https://www.nature.com/natureastronomy/
NASA Hubble Space Telescope
https://www.nasa.gov/mission_pages/hubble/main/index.html
Become a supporter of this podcast: https://www.spreaker.com/podcast/spacetime-space-astronomy--2458531/support.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
This is Spacetime Series twenty eight, episode one hundred and one,
for broadcast on the twenty second of August twenty twenty five.
Coming up on Space Time, did a comet trigger Earth's
Younger Dryas cool off? The discovery of a rare white
dwarf merger remnant, and China tests its new manned lun
orlanda All that and more Coming up on space Time.
Speaker 2 (00:24):
Welcome to space Time with Stuart Gary.
Speaker 1 (00:43):
A new study has raised serious questions as to whether
a massive comet may have triggered planet Earth's Younger Dryas
cool off event. The massive climate change is generally thought
to have been caused by glacial milt water. That analysis
of ocean sediments reported in the journal plus one one
by suggesting geochemical clues in line with the possibility that
(01:03):
an encounter with a disintegrating comet eight hundred years ago
may well have triggered rapid cooling of Earth's air and oceans.
The studies lead author, Christopher Moore from the University of
South Carolina, says that during the abrupt cool off the
Younger Dryous event, temperatures dropped by around ten degrees celsius
in a year or less. With cooler temperatures lasting for
(01:24):
some twelve hundred years. Many scientists believe that no comet
was involved, and that it was glacial melt water in
the northern Hemisphere causing a freshening of the Atlantic Ocean,
significantly weakening currents that transport warm tropical water northwards, such
as the Golf Stream Now. In contrast, the Younger Dryas
impact hypothesis proposes that Earth pass through a debris trail
(01:46):
left from the disintegrating comet, with numerous impacts and shark
waves to stabilizing ice sheets and causing massive melt water flooding,
which then shut down key ocean currents. However, the impact
hypothesis has been less well supported, lacking any evidence from
ocean sediment that address this gap. More on, colleagues analyzed
the geochemistry of four sea four cores from Baffin Biny, Greenland.
(02:09):
Radiocarbon dating suggest that the cause include sediments deposited when
the Younger Drys event began. To study them, the authors
use several techniques including scanning, electro microscopy, single particle inductivity
coupled with plasma time of flight, mass spectrometry, energy dispersive
spectroscopy and laser a Bleason inductivity coupled plasma mass spectrometry.
(02:31):
The analysis detected metallic debris whose geochemistry would be consistent
with comet dust. These occurred alongside microscopic spherical particles whose
composition indicates a mostly terrestrial origin, with some materials believed
to be extraterrestrial. That suggests these microspherals could have famed
when cometary fragments exploded just above or a bond hitting
(02:51):
the ground melting materials together. The analysis also uncovered even
smaller nanoparticles with high levels of platinum, iridium, cobalt, and
these can all be signs of extraterrestrial origin, especially iridium,
which is rare on Earth but common in asteroids and comets. Together,
the findings indicate a geochemical anomaly occurring around the time
(03:13):
that the Younger dryse event began. Of course, they don't
provide direct evidence supporting the impact hypothesis. More research will
be needed to confirm whether the findings are indeed evidence
of an impact and to firmly link the impact climate cooling.
Moore says identification of the Younger Drys impact layer in
the deep marine sediments underscores the potential of oceanic records,
(03:35):
the broadened sciences understanding of this event and its climatological impacts.
He says, the debt is suggests that the amount of
comet dust in the atmosphere was enough to cause a
short term impact winter, followed by a fourteen hundred year
cooling off period. This is space time still to come.
Discovery of a rare white dwarf merger remnant and China
(03:56):
tests its new manned Luna Lander. All that and more
still to come on space time. Astronomers have discovered a
(04:18):
cosmic rarity, an ultra massive white dwarf star, resulting from
a white dwarf merging with another star rather than through
the evolution of just a single star. The discovery, which
is made possible by NASA's Hubble Space telescope sensitive ultraviolet observations,
suggested these very rare white dwarf mergers may be more
common than previously thought. One of the studies authors, Boriskin
(04:40):
Ziki from the University of Warwick, says the discovery underlines
how things can be different from what they appear to
be at first sight. Until now, this object appeared to
be a normal white dwarf but Hubble's ultraviolet vision revealed
that it had a very different history from what astronomers
would have guessed. Now. A white dwarf is the dead
stella core of a sun like star. After fusing their
(05:04):
core hydrogen into helium, they then fuse their core helium
into carbon and oxygen. The process is expanding out to
become a red giant, and because they're not massive enough
to fuse carbon and oxygen into heavier elements, the fusion
process turns off and the star dies. Eventually, they puff
off their outer gaseous envelope, which gradually floats away as
(05:26):
a spectacular colorful object called a planetary nebula, and that
exposes their white, ultra hot stellar core. The white dwarf
a super dense object composed mostly of oxygen and carbon,
usually about the size of the Earth, which will slowly
cool over the eons. Our Sun will eventually become a
white dwarf when it drops off the main sequence in
(05:47):
around five to seven billion years from now now. In theory,
a white dwarf can have a massive up to one
point four times that of the Sun, but usually white
dwarfs heavier than our Sun are fairly rare. These objects,
which astronomers call ultra massive White dwarfs, can form either
through the evolution of a single massive star or through
the merger of a white dwarf with another star, such
(06:09):
as a binary companion. This new discovery, reported in the
journal Nature Astronomy, marks the first time that a white
dwarf borne from merging stars has been identified by its
ultraviolet signature now. Prior to this study, only six white
dwarf merger room thats have been discovered, all by their
carbon spectral lines in their visible light spectra. Now, all
(06:30):
seven of these objects are part of a larger group
of stars that were found to be blue with and
expected for their masses and ages from a study by
the European Space AGENCYSGAIA mission in twenty nineteen, providing new
insights into their formation history. For this lattice discovery, astronomers
used Hubble's Cosmic Origin Spectrograph to investigate a white dwarf
catalog as WD zero five two five plus five twenty six.
(06:54):
It's located one hundred and twenty six light years away
and is about twenty percent more massive than our Sun
now in visible light, the spectrum of the atmosphere of
WD zero five twenty five plus five twenty six resembles
that of a typical white dwarf. However, Hubble's ultraviolet spectrum
revealed something unusual, evidence of carbon in the white dwarf's atmosphere.
(07:15):
White dwarfs that form through the evolution of a single
star have atmospheres composed of hydrogen and helium. As we
mentioned earlier, the core of the white dwarf is typically
composed mostly of carbon and oxygen, but a thick atmosphere
usually prevents these elements from appearing in the white dwarf spectra.
So when carbon does appear in the spectrum of a
white dwarf, it's a signal of a more violent origin
(07:37):
than a typical single star scenario. In other words, the
collision of two white dwarfs or a white dwarf and
another star, and these collisions can burn away the hydrogen
and helium atmospheres of the colliding stars, leaving behind a
scant layer of hydrogen and helium around the merger room
that allows carbon from the white dwarf's core to float
upwards where it can be detected. D E zero five
(08:00):
twenty five plus five twenty six is remarkable even within
the small group of white dwarves known to be the
result of merging stars. With the temperature of almost twenty
one thousand kelvin and some one point two solar masses,
this object is harder and more massive than other white
dwarfs in this group. Its extreme temperature posts something of
a mystery. For cooler white dwarfs, such as the six
(08:22):
previously discovered, merger products a process called convection and mixed
carbon into the thin hydrogen helium atmosphere. The problem is
wdzero five twenty five plus five twenty six is simply
too hot for convection to take place, so instead, the
authors concluded that a more subtle process called sindic convection
brings small amounts of carbon up into the atmosphere, and
(08:44):
this object has the smallest amount of atmospheric carbon of
any white dwarf known to result from a merger, about
one hundred thousand times less than other merger remnants. The
high temperature, low carbon abundance means that identifying this white
dwarf as a product of a merger would have been
in possible without hubble sensitivity to ultraviolet light see the
spectral lines from elements heavier than helium like carbon become
(09:07):
fainter at visible wave links for hotter white dwarfs, but
these spectral signatures remain bright in the ultraviolet. Hubble is
uniquely positioned to spot them because WD zero five twenty
five plus five twenty six's unusual origins were only revealed
once astronomer's glimpsed its ultraviolet spectrum. It's highly likely that
other shavingly normal white dwarfs may actually be out there
(09:30):
as a result of other cosmic collisions, and so the
search is underway. This report from MASSTV.
Speaker 3 (09:38):
Astronomers using NASA's Hubble Space Telescope have found a rare
ultramassive white dwarf formed from merging stars. The discovery was
made possible by Hubble sensitive ultraviolet observations and suggests these
unusual white dwarfs may be more common than once thought.
The white dwarf is one hundred and twenty eight light
(09:59):
years away and twenty percent more massive than the Sun.
Invisible light, it looked like a typical white dwarf, but
hubbles altered violet data revealed something unusual, evidence of carbon
in its atmosphere. A white dwarf is what stars like
the sun become after they exhaust their nuclear fuel. Near
the end of its life, this type of star expels
(10:21):
most of its outer material, creating a planetary nebula. Only
the hot core of the star remains. White dwarfs that
form from a single star usually have atmospheres made of
hydrogen and helium. These thick layers cover its carbon and
oxygen or oxygen and neon surface, preventing their detection in
the star's spectrum. When carbon shows up in a white
(10:44):
dwarf spectrum, it can point to a more violent origin,
such as a collision between two white dwarfs, or between
a white dwarf and a subgiant star. These collisions can
burn off most of the hydrogen and helium, leaving only
a thin layer behind, allowing the astronomers to detect carbon
on the white dwarf's surface. This white dwarf's merger origin
(11:05):
would be impossible to identify without Hubble's ultraviolet sensitivity and
hotter white dwarfs. Spectral lines from elements heavier than helium
fade in visible light and stay bright and ultraviolet where
Hubble can detect them. Researchers discover this white dwarf's unusual
origin by looking at its ultraviolet spectrum, suggesting that other
(11:27):
white dwarfs with a typical visible light spectrum may also
be the result of cosmic collisions. The team plans to
explore this possibility further and hopes to continue this research
by studying how common carbon stars are among similar white
dwarfs and how many stellar mergers might be hiding among
the normal white dwarf family. This research will help improve
(11:51):
our understanding of the environments in which stars evolve and
the paths that lead to supernova explosions.
Speaker 1 (11:57):
This space time to come, China tests its new manned
Luna lander and later in the science report, researchers have
developed new solar powered floating devices so light they can
support instruments high up in the atmosphere. All that and
more still to come on space time, China has successfully
(12:31):
carried out what it claims is the first test of
its future manned lunar landing craft. The China Manned Space
Agency does the test flight at a facility in Hebi Province,
included both the controlled landing and takeoff marking. At major
milestone in Beijing's manned lunar space exploration program, the land U,
which means embracing the Moon in Mandarin is similar in
(12:52):
concept and as this original Apollo era Lunar Excursion Module
or LEM, which brought the first humans to the lunar
surface on Apollo eleven nineteen sixty nine. LANDU is composed
of both a landing module and a propulsion module, and
it's designed to carry two Taygan notes from lunar orbit
down to the surface and back again. It also has
enough room for a lunar rover and scientific equipment. Again
(13:15):
just like Apollo, China says it plans to hab its
first tiger notts walking on the lunar's surface by twenty
thirty and will develop a permanent base on the Moon
with the Russians during the early twenty thirties. This is
space time, and time that to take another brief look
(13:45):
at some of the other stories making use in science
this week. With a science report, scientists are warning that
Argentina is Prito Marina glacier, previously considered to be one
of the most stable in the region, has now began
retreating faster than previously thought. Reporting the journal Communications, Earth
and Environment looked at a combination of satellite data radar
(14:05):
images from helicopter flights and mapping of the lake bed
to estimate how the glacier has changed between the year
two thy and twenty twenty four. Despite retreating less than
one hundred meters from the year two thousand through to
twenty nineteen, the authors found that some areas of the
glacier have been retreating by as much as eight hundred
meters in recent years, with a more than sixteen fold
(14:26):
increase in thinning rates at the glacier's lowest point since
twenty nineteen. The authors wiarn it's now possible that this
glacier is following a similar pattern in other retreating glaciers
around the world. Anthropologists have found that two different groups
of Neanderthals living in two nearby caves butchered the same prey,
but in very different ways. The discovery, reported in the
(14:49):
General Frontiers of Environmental Archaeology, suggests that each group practiced
its own unique local traditions. These Neanderthals, who lived between
fifty thousand and sixty five years ago, used the same
tools and hunted the same prey, but the cut marks
on the remains of their food revealed they were preparing
it in very different ways. Ways that can be explained
(15:11):
simply by the skill of the butchers or the resources
or tools that each of these communities were using. The
authors say that Neanderthals that one cave may have been
drying their meat before cooking it, while the other group
didn't do that. Scientists have developed tiny, solar powered floating
devices that could support instruments high up in the atmosphere.
(15:32):
The devices, reported in the journal Nature, work through a
process called photophoresis, in which motion is generated by heating
particles to spend it in a gas or liquid by
exposing them to sunlight. The authors developed a new type
of flying structure made from two thin, perforated membranes connected
by tiny vertical supports, which they say can levitate under
(15:52):
the amount of light available at high altitudes on Earth.
They're now proposing a three centimeter wide version of this vehicle,
capable of carrying a ten milligram payload that's enough to
support a small communications system panning a radio frequency antenna,
a solar cell, and integrated circuits. They say the devices
have the potential to help monitor the planet's atmosphere and
(16:13):
even help with the expiration of other planets. It seems
a medieval saint may have wrongly predicted the number of
popes before the end of times. Saint Malachi of Armah,
who died in eleven forty eight, is alleged to have
stated in the Prophecy of the Popes that one undred
and ten pontiffs would rain until Judgment Day. But there
(16:34):
may have been some confusion with the prophecy. That's because
of political events within the Catholic Church which have impacted
exactly how many people were anointed as Bishop of Rome.
Tim Mendem from Australian's Skeptics says, then again, Alahai may
simply have got it all wrong.
Speaker 4 (16:50):
Well, we do know about the end of the world
and when it's going to happen, because this saint called
Saint Malachi of Armagh in Ireland made a prediction. He't
from the eleven hundred on his way to Rome. He
hadn't manly said, oh, how many popes have there been?
And based on the number of popes, when you get
to one hundred and eleven actually he said one hundred
and ten, someone else out of another one to when
you get to one hundred and eleven or one hundred
and ten, that'll be the last pope. Unfortunately we just
(17:12):
passed that now to thee and twelve, I think top Yes,
we'll see. In other words, the headline of this story
was did they medieval saint wrong, we predict the number
of popes before the end time? The answer is yes.
The issue is that with only way they assume he lived,
they pretty got They're pretty sure this fellow was a
real person, but it is a real saint in the
eleven hundreds. But this these predictions started appearing a few
(17:34):
hundred years later that he supposedly wrote, so he didn't
necessarily write them, but they's been applied to him and
they're wrong anyway. So it might have been written during
a period of anti popery, great disgiven of the Catholic Church.
Catholic Church can't take their saint wood away from someone
which they've already given to him. Even if he got
his prediction wrong, they're probably quite happy anyway. So the
story goes, this guy made his prediction. It's unfortunately, like
(17:56):
a lot of predictions, we've passed the time. The world
hasn't ended. It is supposed to be the end times,
and the whole thing comes to apocalypse and aged and
whatever sort of particular and you're looking for it was
supposed to be the last post, but was supposed to
be Petrius Romanus, which is Peter the Roman. He identified
as the final pope, and the story goes in the
final persecution of the Holy Roman Church, there will reign
(18:17):
Peter the Roman, who will save his flock amid many tribulations,
after which the seven Hill city will be destroyed and
a dreadful judge will judge the people. So they haven't
got a pope called Petrus or Peter or the Rock.
And therefore whoopsy, as you say, prophecy has not come
true and probably won't come true.
Speaker 1 (18:35):
That's timendum from Austria and Scape Diggs, and that's the
show for now. Space Time is available every Monday, Wednesday
(18:58):
and Friday through Apple podcast, iTunes, Stitcher, Google Podcast, pocket Casts, Spotify, Acast,
Amazon Music, bytes dot Com, SoundCloud YouTube, your favorite podcast
download provider, and from space Time with Stuart Gary dot com.
Space Time's also broadcast through the National Science Foundation, on
(19:18):
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(19:43):
Just go to space Time with Stewart Gary dot com
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Speaker 2 (19:47):
You've been listening to space Time with Stuart Gary. This
has been another quality podcast production from bytes dot com.
This is Spacetime Series twenty eight, episode one hundred and one,
for broadcast on the twenty second of August twenty twenty five.
Coming up on Space Time, did a comet trigger Earth's
Younger Dryas cool off? The discovery of a rare white
dwarf merger remnant, and China tests its new manned lun
orlanda All that and more Coming up on space Time.
Speaker 2 (00:24):
Welcome to space Time with Stuart Gary.
Speaker 1 (00:43):
A new study has raised serious questions as to whether
a massive comet may have triggered planet Earth's Younger Dryas
cool off event. The massive climate change is generally thought
to have been caused by glacial milt water. That analysis
of ocean sediments reported in the journal plus one one
by suggesting geochemical clues in line with the possibility that
(01:03):
an encounter with a disintegrating comet eight hundred years ago
may well have triggered rapid cooling of Earth's air and oceans.
The studies lead author, Christopher Moore from the University of
South Carolina, says that during the abrupt cool off the
Younger Dryous event, temperatures dropped by around ten degrees celsius
in a year or less. With cooler temperatures lasting for
(01:24):
some twelve hundred years. Many scientists believe that no comet
was involved, and that it was glacial melt water in
the northern Hemisphere causing a freshening of the Atlantic Ocean,
significantly weakening currents that transport warm tropical water northwards, such
as the Golf Stream Now. In contrast, the Younger Dryas
impact hypothesis proposes that Earth pass through a debris trail
(01:46):
left from the disintegrating comet, with numerous impacts and shark
waves to stabilizing ice sheets and causing massive melt water flooding,
which then shut down key ocean currents. However, the impact
hypothesis has been less well supported, lacking any evidence from
ocean sediment that address this gap. More on, colleagues analyzed
the geochemistry of four sea four cores from Baffin Biny, Greenland.
(02:09):
Radiocarbon dating suggest that the cause include sediments deposited when
the Younger Drys event began. To study them, the authors
use several techniques including scanning, electro microscopy, single particle inductivity
coupled with plasma time of flight, mass spectrometry, energy dispersive
spectroscopy and laser a Bleason inductivity coupled plasma mass spectrometry.
(02:31):
The analysis detected metallic debris whose geochemistry would be consistent
with comet dust. These occurred alongside microscopic spherical particles whose
composition indicates a mostly terrestrial origin, with some materials believed
to be extraterrestrial. That suggests these microspherals could have famed
when cometary fragments exploded just above or a bond hitting
(02:51):
the ground melting materials together. The analysis also uncovered even
smaller nanoparticles with high levels of platinum, iridium, cobalt, and
these can all be signs of extraterrestrial origin, especially iridium,
which is rare on Earth but common in asteroids and comets. Together,
the findings indicate a geochemical anomaly occurring around the time
(03:13):
that the Younger dryse event began. Of course, they don't
provide direct evidence supporting the impact hypothesis. More research will
be needed to confirm whether the findings are indeed evidence
of an impact and to firmly link the impact climate cooling.
Moore says identification of the Younger Drys impact layer in
the deep marine sediments underscores the potential of oceanic records,
(03:35):
the broadened sciences understanding of this event and its climatological impacts.
He says, the debt is suggests that the amount of
comet dust in the atmosphere was enough to cause a
short term impact winter, followed by a fourteen hundred year
cooling off period. This is space time still to come.
Discovery of a rare white dwarf merger remnant and China
(03:56):
tests its new manned Luna Lander. All that and more
still to come on space time. Astronomers have discovered a
(04:18):
cosmic rarity, an ultra massive white dwarf star, resulting from
a white dwarf merging with another star rather than through
the evolution of just a single star. The discovery, which
is made possible by NASA's Hubble Space telescope sensitive ultraviolet observations,
suggested these very rare white dwarf mergers may be more
common than previously thought. One of the studies authors, Boriskin
(04:40):
Ziki from the University of Warwick, says the discovery underlines
how things can be different from what they appear to
be at first sight. Until now, this object appeared to
be a normal white dwarf but Hubble's ultraviolet vision revealed
that it had a very different history from what astronomers
would have guessed. Now. A white dwarf is the dead
stella core of a sun like star. After fusing their
(05:04):
core hydrogen into helium, they then fuse their core helium
into carbon and oxygen. The process is expanding out to
become a red giant, and because they're not massive enough
to fuse carbon and oxygen into heavier elements, the fusion
process turns off and the star dies. Eventually, they puff
off their outer gaseous envelope, which gradually floats away as
(05:26):
a spectacular colorful object called a planetary nebula, and that
exposes their white, ultra hot stellar core. The white dwarf
a super dense object composed mostly of oxygen and carbon,
usually about the size of the Earth, which will slowly
cool over the eons. Our Sun will eventually become a
white dwarf when it drops off the main sequence in
(05:47):
around five to seven billion years from now now. In theory,
a white dwarf can have a massive up to one
point four times that of the Sun, but usually white
dwarfs heavier than our Sun are fairly rare. These objects,
which astronomers call ultra massive White dwarfs, can form either
through the evolution of a single massive star or through
the merger of a white dwarf with another star, such
(06:09):
as a binary companion. This new discovery, reported in the
journal Nature Astronomy, marks the first time that a white
dwarf borne from merging stars has been identified by its
ultraviolet signature now. Prior to this study, only six white
dwarf merger room thats have been discovered, all by their
carbon spectral lines in their visible light spectra. Now, all
(06:30):
seven of these objects are part of a larger group
of stars that were found to be blue with and
expected for their masses and ages from a study by
the European Space AGENCYSGAIA mission in twenty nineteen, providing new
insights into their formation history. For this lattice discovery, astronomers
used Hubble's Cosmic Origin Spectrograph to investigate a white dwarf
catalog as WD zero five two five plus five twenty six.
(06:54):
It's located one hundred and twenty six light years away
and is about twenty percent more massive than our Sun
now in visible light, the spectrum of the atmosphere of
WD zero five twenty five plus five twenty six resembles
that of a typical white dwarf. However, Hubble's ultraviolet spectrum
revealed something unusual, evidence of carbon in the white dwarf's atmosphere.
(07:15):
White dwarfs that form through the evolution of a single
star have atmospheres composed of hydrogen and helium. As we
mentioned earlier, the core of the white dwarf is typically
composed mostly of carbon and oxygen, but a thick atmosphere
usually prevents these elements from appearing in the white dwarf spectra.
So when carbon does appear in the spectrum of a
white dwarf, it's a signal of a more violent origin
(07:37):
than a typical single star scenario. In other words, the
collision of two white dwarfs or a white dwarf and
another star, and these collisions can burn away the hydrogen
and helium atmospheres of the colliding stars, leaving behind a
scant layer of hydrogen and helium around the merger room
that allows carbon from the white dwarf's core to float
upwards where it can be detected. D E zero five
(08:00):
twenty five plus five twenty six is remarkable even within
the small group of white dwarves known to be the
result of merging stars. With the temperature of almost twenty
one thousand kelvin and some one point two solar masses,
this object is harder and more massive than other white
dwarfs in this group. Its extreme temperature posts something of
a mystery. For cooler white dwarfs, such as the six
(08:22):
previously discovered, merger products a process called convection and mixed
carbon into the thin hydrogen helium atmosphere. The problem is
wdzero five twenty five plus five twenty six is simply
too hot for convection to take place, so instead, the
authors concluded that a more subtle process called sindic convection
brings small amounts of carbon up into the atmosphere, and
(08:44):
this object has the smallest amount of atmospheric carbon of
any white dwarf known to result from a merger, about
one hundred thousand times less than other merger remnants. The
high temperature, low carbon abundance means that identifying this white
dwarf as a product of a merger would have been
in possible without hubble sensitivity to ultraviolet light see the
spectral lines from elements heavier than helium like carbon become
(09:07):
fainter at visible wave links for hotter white dwarfs, but
these spectral signatures remain bright in the ultraviolet. Hubble is
uniquely positioned to spot them because WD zero five twenty
five plus five twenty six's unusual origins were only revealed
once astronomer's glimpsed its ultraviolet spectrum. It's highly likely that
other shavingly normal white dwarfs may actually be out there
(09:30):
as a result of other cosmic collisions, and so the
search is underway. This report from MASSTV.
Speaker 3 (09:38):
Astronomers using NASA's Hubble Space Telescope have found a rare
ultramassive white dwarf formed from merging stars. The discovery was
made possible by Hubble sensitive ultraviolet observations and suggests these
unusual white dwarfs may be more common than once thought.
The white dwarf is one hundred and twenty eight light
(09:59):
years away and twenty percent more massive than the Sun.
Invisible light, it looked like a typical white dwarf, but
hubbles altered violet data revealed something unusual, evidence of carbon
in its atmosphere. A white dwarf is what stars like
the sun become after they exhaust their nuclear fuel. Near
the end of its life, this type of star expels
(10:21):
most of its outer material, creating a planetary nebula. Only
the hot core of the star remains. White dwarfs that
form from a single star usually have atmospheres made of
hydrogen and helium. These thick layers cover its carbon and
oxygen or oxygen and neon surface, preventing their detection in
the star's spectrum. When carbon shows up in a white
(10:44):
dwarf spectrum, it can point to a more violent origin,
such as a collision between two white dwarfs, or between
a white dwarf and a subgiant star. These collisions can
burn off most of the hydrogen and helium, leaving only
a thin layer behind, allowing the astronomers to detect carbon
on the white dwarf's surface. This white dwarf's merger origin
(11:05):
would be impossible to identify without Hubble's ultraviolet sensitivity and
hotter white dwarfs. Spectral lines from elements heavier than helium
fade in visible light and stay bright and ultraviolet where
Hubble can detect them. Researchers discover this white dwarf's unusual
origin by looking at its ultraviolet spectrum, suggesting that other
(11:27):
white dwarfs with a typical visible light spectrum may also
be the result of cosmic collisions. The team plans to
explore this possibility further and hopes to continue this research
by studying how common carbon stars are among similar white
dwarfs and how many stellar mergers might be hiding among
the normal white dwarf family. This research will help improve
(11:51):
our understanding of the environments in which stars evolve and
the paths that lead to supernova explosions.
Speaker 1 (11:57):
This space time to come, China tests its new manned
Luna lander and later in the science report, researchers have
developed new solar powered floating devices so light they can
support instruments high up in the atmosphere. All that and
more still to come on space time, China has successfully
(12:31):
carried out what it claims is the first test of
its future manned lunar landing craft. The China Manned Space
Agency does the test flight at a facility in Hebi Province,
included both the controlled landing and takeoff marking. At major
milestone in Beijing's manned lunar space exploration program, the land U,
which means embracing the Moon in Mandarin is similar in
(12:52):
concept and as this original Apollo era Lunar Excursion Module
or LEM, which brought the first humans to the lunar
surface on Apollo eleven nineteen sixty nine. LANDU is composed
of both a landing module and a propulsion module, and
it's designed to carry two Taygan notes from lunar orbit
down to the surface and back again. It also has
enough room for a lunar rover and scientific equipment. Again
(13:15):
just like Apollo, China says it plans to hab its
first tiger notts walking on the lunar's surface by twenty
thirty and will develop a permanent base on the Moon
with the Russians during the early twenty thirties. This is
space time, and time that to take another brief look
(13:45):
at some of the other stories making use in science
this week. With a science report, scientists are warning that
Argentina is Prito Marina glacier, previously considered to be one
of the most stable in the region, has now began
retreating faster than previously thought. Reporting the journal Communications, Earth
and Environment looked at a combination of satellite data radar
(14:05):
images from helicopter flights and mapping of the lake bed
to estimate how the glacier has changed between the year
two thy and twenty twenty four. Despite retreating less than
one hundred meters from the year two thousand through to
twenty nineteen, the authors found that some areas of the
glacier have been retreating by as much as eight hundred
meters in recent years, with a more than sixteen fold
(14:26):
increase in thinning rates at the glacier's lowest point since
twenty nineteen. The authors wiarn it's now possible that this
glacier is following a similar pattern in other retreating glaciers
around the world. Anthropologists have found that two different groups
of Neanderthals living in two nearby caves butchered the same prey,
but in very different ways. The discovery, reported in the
(14:49):
General Frontiers of Environmental Archaeology, suggests that each group practiced
its own unique local traditions. These Neanderthals, who lived between
fifty thousand and sixty five years ago, used the same
tools and hunted the same prey, but the cut marks
on the remains of their food revealed they were preparing
it in very different ways. Ways that can be explained
(15:11):
simply by the skill of the butchers or the resources
or tools that each of these communities were using. The
authors say that Neanderthals that one cave may have been
drying their meat before cooking it, while the other group
didn't do that. Scientists have developed tiny, solar powered floating
devices that could support instruments high up in the atmosphere.
(15:32):
The devices, reported in the journal Nature, work through a
process called photophoresis, in which motion is generated by heating
particles to spend it in a gas or liquid by
exposing them to sunlight. The authors developed a new type
of flying structure made from two thin, perforated membranes connected
by tiny vertical supports, which they say can levitate under
(15:52):
the amount of light available at high altitudes on Earth.
They're now proposing a three centimeter wide version of this vehicle,
capable of carrying a ten milligram payload that's enough to
support a small communications system panning a radio frequency antenna,
a solar cell, and integrated circuits. They say the devices
have the potential to help monitor the planet's atmosphere and
(16:13):
even help with the expiration of other planets. It seems
a medieval saint may have wrongly predicted the number of
popes before the end of times. Saint Malachi of Armah,
who died in eleven forty eight, is alleged to have
stated in the Prophecy of the Popes that one undred
and ten pontiffs would rain until Judgment Day. But there
(16:34):
may have been some confusion with the prophecy. That's because
of political events within the Catholic Church which have impacted
exactly how many people were anointed as Bishop of Rome.
Tim Mendem from Australian's Skeptics says, then again, Alahai may
simply have got it all wrong.
Speaker 4 (16:50):
Well, we do know about the end of the world
and when it's going to happen, because this saint called
Saint Malachi of Armagh in Ireland made a prediction. He't
from the eleven hundred on his way to Rome. He
hadn't manly said, oh, how many popes have there been?
And based on the number of popes, when you get
to one hundred and eleven actually he said one hundred
and ten, someone else out of another one to when
you get to one hundred and eleven or one hundred
and ten, that'll be the last pope. Unfortunately we just
(17:12):
passed that now to thee and twelve, I think top Yes,
we'll see. In other words, the headline of this story
was did they medieval saint wrong, we predict the number
of popes before the end time? The answer is yes.
The issue is that with only way they assume he lived,
they pretty got They're pretty sure this fellow was a
real person, but it is a real saint in the
eleven hundreds. But this these predictions started appearing a few
(17:34):
hundred years later that he supposedly wrote, so he didn't
necessarily write them, but they's been applied to him and
they're wrong anyway. So it might have been written during
a period of anti popery, great disgiven of the Catholic Church.
Catholic Church can't take their saint wood away from someone
which they've already given to him. Even if he got
his prediction wrong, they're probably quite happy anyway. So the
story goes, this guy made his prediction. It's unfortunately, like
(17:56):
a lot of predictions, we've passed the time. The world
hasn't ended. It is supposed to be the end times,
and the whole thing comes to apocalypse and aged and
whatever sort of particular and you're looking for it was
supposed to be the last post, but was supposed to
be Petrius Romanus, which is Peter the Roman. He identified
as the final pope, and the story goes in the
final persecution of the Holy Roman Church, there will reign
(18:17):
Peter the Roman, who will save his flock amid many tribulations,
after which the seven Hill city will be destroyed and
a dreadful judge will judge the people. So they haven't
got a pope called Petrus or Peter or the Rock.
And therefore whoopsy, as you say, prophecy has not come
true and probably won't come true.
Speaker 1 (18:35):
That's timendum from Austria and Scape Diggs, and that's the
show for now. Space Time is available every Monday, Wednesday
(18:58):
and Friday through Apple podcast, iTunes, Stitcher, Google Podcast, pocket Casts, Spotify, Acast,
Amazon Music, bytes dot Com, SoundCloud YouTube, your favorite podcast
download provider, and from space Time with Stuart Gary dot com.
Space Time's also broadcast through the National Science Foundation, on
(19:18):
Science Own Radio and on both iHeartRadio and tune in Radio.
And you can help to support our show by visiting
the Spacetime store for a range of promotional merchandising goodies,
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(19:43):
Just go to space Time with Stewart Gary dot com
for full details.
Speaker 2 (19:47):
You've been listening to space Time with Stuart Gary. This
has been another quality podcast production from bytes dot com.
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