Comet 3I Atlas - The Interstellar Voyager Unveiled

In this episode of SpaceTime, we explore the latest revelations from the cosmos, featuring the intriguing interstellar comet 3I Atlas, a groundbreaking theory about our place in the universe, and the safe return of SpaceX Crew 10.
The Enigmatic Comet 3I Atlas
Astronomers utilizing NASA's Hubble Space Telescope have captured the sharpest images yet of the interstellar comet 3I Atlas, revealing a solid icy nucleus estimated to measure between 320 meters and 5.6 kilometers in diameter. This comet, traveling at a staggering 209,000 kilometers per hour, is believed to have been journeying through interstellar space for approximately 7 billion years. Observations from multiple telescopes are enhancing our understanding of this ancient visitor, including its size, chemical makeup, and physical properties. With a dust plume and tail reminiscent of solar system comets, 3I Atlas offers a unique glimpse into the history of our galaxy as it approaches the sun.
Earth's Position in a Cosmic Void
A new hypothesis suggests that Earth and the Milky Way may reside in a vast cosmic void rather than along a filament of the universe's cosmic web. This idea could help resolve the Hubble tension, a discrepancy in the rate of the universe's expansion. The study, presented at the Royal Astronomical Society's National Astronomy Conference, posits that our galaxy might be near the center of a local void, influencing the observed expansion rate of the universe. This intriguing concept challenges existing cosmological models and could reshape our understanding of cosmic structure.
Safe Return of SpaceX Crew 10
After five months aboard the International Space Station, SpaceX Crew 10 has safely returned to Earth. Their Dragon capsule splashed down in the North Pacific Ocean, marking the end of a mission that contributed to over 200 scientific experiments, ranging from plant growth studies to the effects of microgravity on human physiology. The crew's successful return paves the way for their replacements, Crew 11, to continue vital research in low Earth orbit.
www.spacetimewithstuartgary.com
✍️ Episode References
Astrophysical Journal Letters
https://iopscience.iop.org/journal/2041-8205
Royal Astronomical Society
https://ras.ac.uk/
NASA's Hubble Space Telescope
https://www.nasa.gov/mission_pages/hubble/main/index.html
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Episode Transcript

Speaker 1 (00:00):
This is Spacetime Series twenty eight, episode one hundred, for
broadcast on the twentieth of August twenty twenty five. Coming
up on Spacetime, new details about our latest interstellar visitor,
three Eye Atlas, a new theory suggesting Earth in the
Milky Way galaxy may be located deep inside a cosmic void,

(00:20):
and Space Station Crew ten returned safely to Earth. All
that and more coming up on space Time.

Speaker 2 (00:28):
Welcome to space Time with Stewart Gary.

Speaker 1 (00:48):
Astronomers using Nassas Hubble Space Telescope have taken the sharpest
observation jet of our latest interstellar visitor, the comet three
Eye Outlas. The new data, reported in the Astrophysical Journal
let have provided the best images yet of this mysterious object.
Astronomers say that, based on their observations, three I Atlas

(01:08):
has a soldid icy nucleus which is somewhere between three
hundred and twenty meters and five point six kilometers in diameter.
The exact size is somewhat open to interpretation because the
nucleus is surrounded by a thick, dusty COMA. Hubble is
one of numerous observatories either in orbit or on the
ground intensely studding this comet. Observations from other NAS emissions,

(01:30):
including the web Space Telescope, a Transiting Exoplanet Survey, satellite tests,
and the Swift Space Telescope, as well as ground based
observatories like the ten meter KECTWINS in Hawaii, will help
to further refine sciences understanding about the comet, including its
exact size, chemical makeup, and physical properties. Hubbles also capture
a dust plue ejected from the sunwarm side of the

(01:52):
comet and the hint of a dust tail streaming away
from the nucleus. Hubble datas yielding a dust loss rate
which is consistent with Solar System comets when they're first
detected around four hundred and eighty million kilometers from the Sun.

Speaker 3 (02:05):
So this behavior is.

Speaker 1 (02:06):
Very much like the signature of previously seen sunbound comets
originating from within our Solar System. Of course, the big
difference is that this interstellar visitor originated from another star
system somewhere else in the galaxy three I outlets, is
traveling through our Solar System at a staggering two hundred
and nine thousand kilometters per hour. That's the highest velocity

(02:26):
ever recorded for any interstellar visitor. It's breathtaking velocity. It's
evidence that the comet's been traveling through interstellar space for
many billions of years. Current estimates suggest that it could
be seven billion years old. The gravitational slingshot effect from
innumerable stars and nebuly encountered by the comet during its
journey has added momentum ratcheting up at speed, and the

(02:48):
longer three eye outlasts was out there in space, the
higher at speed grew. Science team leader for Hubble observations,
David Jewett from the University of California, Los Angeles, no
one knows for sure exactly where this comet came from.
He says, it's a bit like glimpsing a rifle bullet
in flight for just a thousandth of a second. You
simply can't project that object back with any degree of

(03:11):
accuracy to figure out exactly where it started.

Speaker 3 (03:13):
On its path.

Speaker 1 (03:14):
The comet will remain visible to ground based telescopes for
the rest of this month and through September, after which
time it will pass too close to the Sun to
be observed, but is expected to reappear on the other
side of the Sun by early December. This report from Nasstva.

Speaker 4 (03:29):
Using NASA's Hubble Space telescope, a team of astronomers captured
the clearest image to date of the unexpected interstellar commet
three I Atlasts. Astronomers are now able to more precisely
estimate the size of the comet's solid icy nucleus. Its
estimated diameter is no bigger than three point five miles across,

(03:52):
but potentially as small as one thousand feet across. Hubble
captured a dust plume ejected from the sun worn side
of the comet and the hint of a tear drop
shaped dust tail streaming away from the nucleus. This behavior
is similar to that of previously seen sunbound comets originating
within our Solar System. The big difference is that this

(04:15):
mysterious visitor came from an ancient and unknown realm of
our Milky Way, launching from an undetermined star system long
ago and far away. In what may be the final
chapter in its space odyssey, three I Atlas is plunging
towards the Sun at a staggering one hundred and thirty
thousand miles per hour. This is the highest velocity ever

(04:38):
recorded for a Solar System visitor. The comet's astonishing speed
suggests it has traversed interstellar space for billions of years.
The comet gained speed due to the gravitational slingshot effect
of the stars and other objects it encountered. The longer
three Iatlists traveled through interstellar space, the faster it moved.

(05:00):
Hubble observations suggest that Commet three Iatlists was likely expelled
from a developing planetary system. This occurred as icy bodies
aggregated within an outer disc or ring surrounding a star,
further supporting the idea that such outer belts are common
in planet forming systems. Another possibility is that three iat

(05:23):
Lists is just a fragment of a small icy planet
that came too close to a white dwarf star, disintegrated
under the stress of gravity and scentence, shards cannon balling
back into space. Three Iatlis is an icy fossil from
a time perhaps before Earth even existed. If three iAtlas

(05:43):
has wandered among the stars for nearly half of the
Milky Way's age, it provide insights into the history of
our galaxy and the processes behind our solar system's formation.
Comet three Iatlists will make its closest approach to the
Sun in October twenty twenty five, but don't worry, it
won't be anywhere near Earth. NASA's assets, including Hubble, the

(06:06):
James Webb Space Telescope, the Transiting Exoplanet Survey Satellite, and
the Swift Observatory, will closely monitor the commet to measure
its chemical composition as the Sun's heat further sublimates its ices.
Should it survive the perilous journey near the Sun, the
chances of three I Atlas experiencing another close encounter with

(06:28):
a star are incredibly remote. It's also possible that three
I Atlas, like many fragile commet nuclei, approaching the Sun,
could break apart or disintegrate into dust, bringing its existence
to an end. Each new discovery offers astronomers valuable insights
into both our own Solar System and the distant universe

(06:49):
beyond Tree.

Speaker 1 (06:50):
I Atlas is only the third interstellar object ever observed
to be traveling through our Solar System. There have a
dadly been others, are there only three we know about
for sure. The first was a mal Maur, which was
discovered back on October the nineteenth, twenty seventeen, approximately forty
days after it passed its closest point to the Sun
on September the ninth. When it was first observed, mail

(07:12):
Mao was around thirty three million kilometers from Earth and
already heading out of the Solar System. It's estimated to
be between one hundred and one thousand kilometers in length,
with a width and thickness estimated to be between thirty
five and one hundred and sixty seven meters.

Speaker 3 (07:26):
Interestingly, it has a.

Speaker 1 (07:28):
Reddish color similar to objects from the outer Solar System.
Even more fascinating, despite its close approach to the Sun,
it showed no signs of having a coma, the usual
nebulau seen around comets, which is formed as they passed
near the Sun and are heated up, allowing volatile gases
to expand an escape. Also, a mal Maour appears to
be tumbling rather than spinning as it moves. Interestingly, it

(07:51):
exhibited a sudden non gravitational acceleration as it left the
Solar System, possibly either due to outgassing or a push.

Speaker 3 (07:58):
From solar radiation pressure.

Speaker 1 (08:00):
As best as we can tell, a mal Mara apiece
to have come from roughly the direction of Vega in
the constellation Lyra It entered our Solar System from the
north of the plan of the Ecliptic on a strongly
hyperbolic trajectory. The Sun's gravity then bent its orbit in
a sharp turn again northwards, and it's now heading away
from the Sun towards the constellation Pegasus. The second confirmed

(08:23):
interstellar visitor was the comet two I Borisov, which was
first observed on August the twenty ninth, twenty nineteen. Borisov
passed through the ecliptic of the Solar System at the
end of October twenty nineteen, and that its closest approach
to the Sun on December the eighth of that year.
Early estimates suggested the nucleus of the comet is somewhere
between one point four and sixteen kilometers wide, and unlike

(08:45):
Solar System comets, Borisov noticeably shrunk during its Solar System flyby,
losing at least zero point four percent of its mass
before perihelion, its closest approach to the Sun, Borisov entered
our Solar system from the direction of Cassiopea in the
border with Perseus, on an extremely hyperbolic trajectory. Now this
direction indicates it probably originated from the galactic plane rather

(09:09):
than the galactic halo. It's leaving our Solar System in
the direction of the constellation Teroscopium. This space time. Still
to come is planet Earth, and for that matter, the
Milky Way in a cosmic void, and four SpaceX crew
teen astronauts have returned safely to Earth after spending five
months aboard the International Space Station. All that and more

(09:31):
still to come on space time observations to astronomers that

(09:51):
the large scale structure of the universe is shaped sort
of like a giant cosmic web, comprising filaments of galaxies,
galaxy clusters, and superclusters spread around the edges of giant,
near empty voids. Now, a new hypothesis has revived the
idea that planet Earth, and for that matter, our entire
Milky Way galaxy, may not be residing along one of

(10:12):
the filaments of the cosmic web, but rather inside one
of the giant voids, and that's making the universe expand
faster here than in neighboring.

Speaker 3 (10:21):
Regions of the cosmos.

Speaker 1 (10:23):
The idea is a potential solution to the Hubble tension,
and it could help confirm the true age of our universe,
which is currently estimated to be around thirteen point eight
two billion years. The new research provided of the Royal
Astronomical Society's National Astronomy Conference in Durham shows that pressure
waves from the early universe, essentially the sound ways from
the Big Bang, support this idea. The Hubble constant, first

(10:47):
proposed by Edwin Hubble in nineteen twenty nine, is designed
to express the rate at which the universe is expanding.
It can be measured by observing the distance of celestial
objects and how fast they're moving away from us. The
stumbling block, however, is that extrapolating measurements of the distance
of the early universe to today using the standard cosmological

(11:07):
model predicts a slower rate of expansion. The measurements of
the nearby, more recent universe indicate this is the Hubble tension.
The Steadies, lead author in Grenelled Banning from the University
of Portsmouth, says a potential solution of this inconsistency is
that the Milky Way galaxy that includes the Earth may
be close to the center of a large local void.

(11:29):
Bannick says that would cause matter to be pulled by
gravity towards the higher density exterior regions of the void
where the filaments are leading to the void becoming emptier
with time. As the voids emptying out, the velocity objects
away from us would be larger than if the void
simply wasn't there. This therefore gives the appearance of a
faster local expansion rate even explained dark energy. Bannik says

(11:53):
that would mean the Hubble tension is largely a local phenomenon,
with little evidence that the expansion rate disagrees with expectations
in the standard cosmology further back in time. So a
local solution like a local void is a promising way
to go about solving the problem. But for the idea
to stand up, planet Earth in our Solar system would

(12:14):
need to be near the very center of the void,
about a billion light years in radius and with a
density about twenty percent below the average for the rest
of the universe as a whole. Now directly counting galaxies
does support this theory. That's because the number density in
our local universe is lower than in neighboring regions. However,
it doesn't mesh particularly well with the standard model of cosmology,

(12:36):
which suggests that matter today should be more uniformly spread
out on such large scales. Despite this, the new data
shows that baryon acoustic oscillations pressure wasts from the Big
Bang do support the idea of a local void. These
waves traveled for any short period of time before becoming
frozen in place once the universe cooled enough for neutral

(12:56):
atoms to form. They act as a standard cosmic ruler
whose angular size can be used to chart the cosmic
expansion history. A local void slightly distorts the relation between
the baryon acoustic oscillation's angular scale and the red shift
how far the universe has expanded simply by the stretching
of space time. That's because the velocity is induced by

(13:18):
a local void and its gravitational effect slightly increase the
red shift on top of that due to cosmic expansion.
By considering all available baryonic acoustic ossolation measurements over the
last twenty years, the authors have shown that AVOID model
is about one hundred million times more likely than AVOID
free model with parameters designed to fit the cosmic microwave

(13:39):
background observations taken by the Plank satellite, the so called
homogeneous Plank cosmology. The cosmic microwave background is a relic
radiation that fills all space time and the observable universe.
It occurred about three hundred and eighty thousand years after
the Big Bang, when subatomic particles in the quak glue

(13:59):
on plasma cooled enough to come together to form the
first atoms, and its remnants are still there, filling the
entire universe that now cooled down to just two point
seven degrees above absolute zero. In fact, if you have
an old analog radio or TV, you can actually see
and hear the cosmic microwave background as the white noise
static you get between channels. This is space time still

(14:24):
to come. Another crew from the International Space Station returned
safely to Earth, and later in the Science report, researchers
develop a new brain interface computer that can read your
mind with a seventy four percent accuracy rate. All that
and more still to come on space time. Four SpaceX

(14:58):
crew ten astronauts have returned safe back to Earth after
spending five months aboard the International Space Station. Their drag
and capsule Endurance splashed down in the North Pacific Ocean
off the California coast, just six hours after undugging from
the orbiting outpost. They've been replaced by four SpaceX crew
eleven team members who arrived on station last week. During

(15:20):
their stay on station, the team contributed to more than
two hundred scientific experiments, including studying plank growth, house cells
interact to gravity, and the effect of micro gravity on
the human eye. This is Space Time and time out

(15:50):
to take another brief look at some of the other
stories making use in science this week with a science report.
A new study suggest a Mediterranean style diet may help
slow down cognitive decline. A report in the Journal of
the American Medical Association measured hippocampal sclerosis, a severe decline
in brain cells and processes in areas of the brain

(16:10):
linked with dementia in Alzheimer's. The stud involved eight hundred
and nine people for whom dietary information and brain autopsies
were available. They found those on diets which combine elements
of a Mediterranean diet and dietary approaches to stop hypertension
were less likely to have signs of hyppocampal sclerosis in
their brains. You authors say the finding suggests that sticking

(16:32):
to a Mediterranean diet may well help reduce the risk
of dementia and Alzheimer's disease. Scientists have discovered fossil evidence
of a new species of ancient whale on Victoria's surf coast.
The findings, reported in the Zoological Journal of the Linum Society,
claims the twenty six million year old dolphin cy citation
and Jenesustis dallati, is based on the partial skull and earburns,

(16:56):
as well as teeth. First uncovered in twenty nineteen, it
featured a short snout, large forward facing eyes, razor sharp
slicing teeth, and a compact body built for hunting.

Speaker 3 (17:07):
The study, which is thought to have a bit of a.

Speaker 1 (17:09):
Juvenile, offers remarkable insights into the early evolution of baileen whales,
the filter feeding giants now cruising our oceans. Scientists have
developed a new brain computer interface that can read your
mind with a seventy four percent accuracy level. A report
in the journal Cell claims the device could even decode
your inmost thoughts. The authors measured brand activity in four

(17:33):
people who had SEV paralysis from murder, neurine disease, or
brainstem stroke, recording their inner speech data. They then trained
an artificial intelligence model to interpret the imagined words.

Speaker 3 (17:44):
The AI was.

Speaker 1 (17:45):
Able to decode sentences from a vocabulary of up to
one hundred and twenty five thousand words with an accuracy
level of seventy four percent. They also demonstrated that it
could use a password to start the system decoding, such
as Chitty Chitty Bang Bang, which it was able to
wreckon with ninety eight percent accuracy. Also say the new
findings could help people communicate even if they're unable to

(18:07):
audibly speak. All the final countdowns now on the way
to tomorrow's launch of the latest Google Pixel Tense smartphones.
Rumors suggests the new phone will include a Tensor G
five chip, higher spec cameras, a new range of colors,
battery upgrades, and the ability to work with megasef accessories
just like Apple. With the details, we're joined by technology

(18:29):
editor Alex saharov Roy from Tech Advice.

Speaker 5 (18:31):
Start life to the Tense generation of Google's phones, and
currently they have the regular model, they have two pro
models or a smaller one and a large one, and
they have the folding phone as well. So there's going
to be faster processes, better cameras, more AI and they're
going to really give a challenge to what Apple is
doing because Apple is behind.

Speaker 1 (18:50):
They're late birth with a folding phone and also with
their AI as well.

Speaker 5 (18:54):
Yeah, Apple has been working on having a folding phone
with no creature in the screen, and the screen supplier
is Samsung. Earlier this year did show off a folding
screen technology that had no crease. But obviously it takes
time to go from a model that you show at
a trade show to a model that is able to
be produced at the scale thatt both Samsung requires for
its own devices, and of course at the scale that

(19:14):
Apple requires, which is in theory many orders of magnitude
more because of course Apple sells for most phones compared
to anybody else. Now, Apple has been working very hard
on AI, but it's had a number of its staff
stolen effectively hied away by Open AI or most notably Meta.
I mean Meta, which is the company behind Facebook, is

(19:34):
wanting to pay one research in particular a quarter of
a billion dollars. I mean that's serious money to steal
somebody away from Google, or from Apple or from anybody else.
That reports have come out in the last week or
so that Apple is going to have not only a
much smartest serie, but robots that are one is like
a Pixar style lamb. It's a robot that can sit
on a table and it can talk to you and
do various things. They're talking about humanoid robots as well.

(19:56):
And look, you know, some of these things are plans
that will change by the time you know, anything comes
to fruition. And some of this is just simply Apple's
way to say, look, we're doing stuff too. And the
big theme of twenty twenty five is agentic AI, where
AI is not simply answering questions anymore about anything that
you ask it, but can now do things for you,
call people, search things, give you reports, give you recommendations.

(20:19):
And this is what the sci fi robots of the
future have been portrayed as doing for decades to come true.

Speaker 3 (20:24):
Too.

Speaker 1 (20:25):
Was the year that George Jetson was meant to be born, Yes,
twenty sixty two, that was when the Jetsons were set.

Speaker 5 (20:31):
Yeah, I mean, we still don't have George Jetson car
that can shrink down into the size of a briefcase
reality and all the job yet. Yeah, that's right, I'm
looking forward to that happening one day. I mean, of course,
basically these Brockets did have Zoom predicted. We do, of course,
have all sorts of robots vacuums. Well, we have all
sorts of a robot vacuum cleaners. It's a no brainer
that we're going to have home robots in the style

(20:54):
of Optimus, in the style of a humanoid android that
will be able to have multiple tasks within.

Speaker 1 (21:00):
The next five years. They're talking about that, and they
won't be that expensive.

Speaker 5 (21:03):
Yeah, that's the beginning. Obviously. We want robots to effectively
become as affordable as a good smartphone is.

Speaker 3 (21:09):
Today.

Speaker 1 (21:09):
That's alex ohrrol Royd from Tech Advice, Start Life, and
that's the show for now. Spacetime is available every Monday,

(21:32):
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Time with Stuart Gary dot com. Space Time's also broadcast
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(21:55):
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(22:18):
to space Time with Stewart Gary dot com for full details.

Speaker 2 (22:22):
You've been listening to space Time with Stuart Gary. This
has been another quality podcast production from bytes dot com.